Earlier last year i convinced my dad to let me install a DIY pool-water circulating system on his 16kW panels in Spain. Panels temps dropped from 85°C at 30°C ambient to about 45-50°C. Average power output on a cloud free day jumped about 17% in addition to eliminating the pool heater in spring and fall. Since this house is completely off-grid, the savings in diesel already made up for the $800 cost. The system is not perfect and was more of a prototype that worked too good to tear it down. Super cheap plastic sheets glued on the back of the panels with about 1cm gap and sealed on all four sides. Fittings are epoxied straight onto the plastic. Water flows in parallel through all panels, two redundant overpowered pumps are controlled by an ESP32 with Wifi for fault notification and temp measurements. Next upgrade would be a water to water heat exchanger to be able to run automotive coolant. In theory i could push air through the same pipe when pool-temps get to high, might test that this year
This is the way. In the video setup, if you lose power to the fans, or the fans fail, you'll cook the panel fast. With a water cooling loop, you still have air flow if things break. And, over a long enough timeline, something will fail. I have an 18kw system that I DIY'ed, with half mounted on a roof, half on the ground. I water cooled a 6kw section of the array and am seeing similar results. The heat is dumped into the ground. The pump is powered by a panel that was badly damaged during shipping, but still makes power.
@@ur_quainmaster7901 Not to mention how long do those small fans cost? And how much work would be involved in pulling a panel out of a large roof mounted array, to replace a fan? I think a much better way to go about this if you have the land area, is just build a ground mount array, so the panels always have free air flow around them, and makes the array itself easier to service, and also not get in the way of roof repairs. But if you don't have the land space, and/or don't want the eyesore of a huge ground mount array, then mounting on the roof and using the waste heat to heat water for a pool, showers etc, is a very good idea.
@@ur_quainmaster7901 I assume they would connect the fans across the panel with a voltage regulator in practice so that never happens, if the panel is hot it's making power.
Guys please take the time to appreciate what this channel is doing. They are producing top notch content, super educational, very well produced and they at no point read any sponsored ads, they don't ask for you to join their Patreon, they don't sell you merchandise, this is unheard of in the world we live today. So much effort goes into these videos and I'm always blown away how sincerely the content is delivered, if you haven't subscribed, just click a button real quick and forget about it, or at the very least leave a like, the value proposition is very fair.
They were supposedly going to sell their thermal paste. I put in an order and heard nothing. No communication of any kind. I eventually had to do a charge back through PayPal.
I agree this man puts out some of the best content out there for useful scientific information and self edification. I always look forward to his new content and have learned so much from his work. I dont know his name and I should but I'd like to thank him right now for all of his effort and knowledge that is so generously given to us watching. Thank you Sir! So nice to know that there are still those out there that teach just to enrich the lives of their fellow man. Bravo Sir.
This is truly a scientific good old style educational channel. The presenter shows a rare combination of beautifull understandable English - important for foreign listeners, huge knowledge and intelligence.
The ONLY thing I could suggest is to run a side by side comparison of the two identical panels, one actively cooled, and one not. I'd like to see data logging and graphing the way Matthias Wandell does. Face them due south and let them run for a full 12 hours.
I’d like to see this as well. During the initial control test measurements, I wondered if the unpowered cooling system has a greater temperature than the unmodified PV panel.
@@jasonwisser3253 It's unlikely that the modified PV is hotter than the unmodified one. They receive the same number of photons that create the waste heat this modification is addressing.
Yes, and drive the fans by the produced energy off of the cooled solar panel through a buck converter set at the fans most efficient voltage. Adding any external power through a power supply does not make sense for a scientific efficiency measurement.
@@jasonwisser3253 Good point. Tough to tell. The added heatsinks on the back may have even lowered the temperature of the panel when the cooling was disabled. It's not a perfect test.
Love it! In my 4KW PV array in upstate New York, I was distraught in winter when an inch of snow dropped output to zero. I disconnected the array from the Controller, and fed pulsating DC from a 240 volt bridge rectifier to the panels. In an hour, enough of the snow melted to begin self-defrosting. Reconnected the controller and produced power the rest of the day instead of zero power. Wish that switching was an option of the controller! Could easily be fully automatic.
I like what you have done to improve solar efficiency. 30 years ago I started adding solar pool heating strip to the back of panels. It has 10 pipes moulded in a rubber strip. Usually glued to the roof to heat a pool, it is easy to serpentine it across a row of panels 3 times and slitting it at the turn-rounds. A small 12 panel driving a 12v solar HW-heating pump will auto speed-control according to the sun on the panel and thus be self compensating. Air cooling is poor compared to water and more than one fan is a big no, no, as one fan will pull through the others. You can always dump the heat into a pool or a heat pump via a car radiator, so its not necessarily wasted.
some people just call it being thorough. it's amazing how capitalism has trained us to think that simply being thorough is somehow going above and beyond. it's also known as doing something right
30 years ago I was living in my RV in the Colorado mountains for a couple of years and getting my electrical power from PV panels. Plus I was spending my days designing a MPPT charge controller, so I spent a whole lot of time thinking about PV panels. You covered everything I experimented with, as well as contemplated regarding thermal management and optimization with the exception of reflectors in low light situations. And the use of reflectors in normal sun was something you have covered in the past. So well done. Thanks for educating many people regarding PV's. While PV cell technology is improving every day, the fundamental fact is that nothing beats the basic physics and applications knowledge for getting the most out of PV's, and you are providing it.
Frankly, I don't think a 10 minute test (not to mention with active tracking) shows ANYTHING. All we really "learned" is what we already knew, which is that fans move air.
@@tarstarkusz We learned that at that small scale, we can gain more output than we are taking out. We learned it is feasible enough to try further, longer, and maybe more costly scenarios.
I absolutely love this channel. Can't get enough of the discussions and the experiments. I'm thinking about how to apply these ideas to my practical life and as a nerd, I'm all in. But as a consumer, I'd probably just buy more solar panels to get more output rather than attempt to make them more efficient. Assuming I had the space to put them somewhere, of course.
1:05 No one really does that anymore... For monocrystalline solar cells like the one you're holding, you start with a doped silicon wafer. On the front side, you would texture the surface and typically heavily dope it with phosphorus and then throw on like 80 nm of Silicon Nitride for passivation and antireflection. On the back you would just screen print an aluminum rich paste for the rear contact (Ag on the front). After the printing, you send it into a belt furnace (glorified pizza oven) at 700-800 C which burns off the organic binders in the pastes and causes the metal to contact the wafer. On the back, the aluminum actually forms a eutectic alloy with silicon that assists carrier collection. Let me know if you want more deets.
Yes it's high quality output every drop and the person who makes and does the demonstrations is such a good speaker and character. I like the guy and i don't actually know him, he is personable
I agree. This well presented content uses the scientific method and rational thinking for its conclusions. No hype, no BS. He takes the viewer on a logical journey with a payoff in the end. Just look around you at the average person and it's easy to conclude that they are looking for something else. Keep up the good work, we'll be watching!
@@chiphill4856 No matter how much I like this channel, the content doesn't make my day in the same way as waching a video of a cat falling down the stairs...
On my RV I have considered installing a copper spiral on the back of the panel to act as a hot water maker. After seeing your results I imagine it would also be worthwhile as a secondary benefit of cooling the panel and improving efficiency. On an RV or boat everything should have at least 2 uses/benefits.
If you do a copper spiral, you should try to do something to soak up the extra heat as evenly as possible. If other portions of the panel are still super hot, those portions may be a weak link that prevents you from being able to tap into a lot of the extra efficiency you'd gain by cooling the parts in contact with the copper coil. Maybe get a flat sheet of copper that is the same size as the back of your solar panel, then use some plumbing solder to tack down your copper coil to the sheet. Use some thermal grease or compound of some sort between the panel and the copper sheet, as well as between the copper sheet and the copper coil. That way the solder is only needed for securing the coil in a few places.
@@MR-nl8xr I would certainly NOT buy new copper. I would find an old solar water heater panel that someone was scrapping and buy it from them cheap. A lot of them have a full sheet of fairly thick copper inside that the tubing was soldered to. The solder usually is about oxidized off by the time someone scraps their solar panel, so it shouldn't be too hard to get it off so that you can run your own tubing pattern. The scrap value of a 4'x10' sheet of copper is well under $300.
I have 400watts of panels mounted on the top of my motorhome. I was unaware that the heat hurts them like that. I will absolutely be making covers for them for when the motorhome is in storage now. we hit 45 C in the summer where I live. I bet those things are hitting 100 or more in the blazing sun. And if they aren't even doing anything I better have them covered! Thank you for the video! I love learning new stuff!
Typically they design these with a 30-50% excess margin built in due to the fact that they do degrade slowly over time. The biggest help will be adding extra batteries to such a system. If your RV can fit an extra 4 or 8 batteries, it's often well worth it versus having to replace the panels in a decade or so.
We can simplify this even further. His objective approach to thinking about the world makes him an excellent role model. Children need strong role models who figure out solutions to problems. I teach Grade 1 and I think we should be very aware that the upcoming generation doesn't seem to be interested in projects or hobbies such as these (most parents of these children don't seem to have any interesting hobbies either). This has nothing to do with school either. It seems most people now prefer to watch rather than to do (just as we are doing on this RUclips video). We need to be engaging children in doing things, rather than watching things. That's my opinion at least. Tech Ingredients does a great job of trying to engage the viewer in practical science (look how engaged the comment section is in every video). My hope is that people leave these RUclips videos and are inspired to figure out problems on their own too.
I really like what you guys are doing in terms of your production quality!! IMO Arguably the best content and articulation of such on RUclips. Keep up the awesome work guys!!
Professor, great video. I love to learn, even at 68 yrs old. I have to say, you’re my go to channel if I want to learn about your projects. This project has really excited me. Thanks for taking your valuable time to teach us.
When I installed my Australian arrays I was tempted by the Dualsun panels using a water loop to dump heat into the 50K liter pool as a heat sink. I think you’ve inspired me to revisit active cooling for the next array to compare performance directly. Maybe I’ll find room for a sunnovate panel too.
Try plumbing the heat exchanger that's connected to an accumulator, similar to an AC or refrigerator set up. This should let you concentrate the heat/waste energy to be converted to something more usable, perhaps captured from a peltier stack.
Here in Australia we sometimes have forced air ventilation of roof spaces to reduce the heat gain through the ceiling, so in those cases you could even just redirect that existing airflow to behind the panels for an even greater efficiency gain and very low capital outlay. Likewise with air conditioners, commercial buildings usually have about 0.7 air changes per hour, so all that chilled air being discarded could be blown behind the panels.
It would be interesting to see the effect of just the heat sink fins and an open back vs the closed back and fans. I feel like the convective flow over the fins might be enough to tip the energy balance toward the passive design without fans.
Passive cooling has a better chance than active cooling. Good fans are freakin expensive, I bet you'd try to save the solar panels by adding fans and end up spending on ton replacing burnt up fans, when you could have just added more panels. Solar panels are too cheap these days to make this stuff make sense. Put as many panels as you can fit on your roof and be done with it, unless you're willing to lower your ROI because it's pet project or whatever.
I spent hours designing a passive solar tracking system that should add 20% to daily solar harvesting, but cost 20-25% additional for the array. In the end, adding 20% more panels with no moving parts was the wiser solution.
Open air natural convection cooling may be a workable thing in higher latitudes, but in lower latitudes, the sun may be directly overhead (or further, towards the poles), and the panels may lie flat. There's no real possibility of natural convection for a panel laying flat - forced convection would be a must-have. And cooling would be even more critical. For much of summer, the sun is actually a few degrees north of us in Phoenix, AZ (about 33 deg North latitude). Temperatures (in the shade) typically exceed 110°F (43°C) from 11AM to 5PM.
@@brettd5884 Non-tracking, fixed angle systems are set halfway between the summer and winter solstice angles which is fairly close to the local latitude. So Phoenix, AZ would have a fixed angle of roughly 33 degrees.
Rotating and moving up and down to peak the panel output, Plus a passive heat sync is more efficient than putting fans on the back. Most Solar panels are not even pointed directly at the sun for any meaningful amount of time. So, they never see peak efficiency... but for a couple of minutes a day.
We typically just add a little more solar :) Also, it seems like your aluminum backing is trapping hot air causing your starting temperature to be higher than it would with an open back and angled panel.
I continue to be impressed by the editing on these videos especially for the intros. And how long the takes are, it's not easy to do that many lines in a row! Each of these videos is a masterclass, kudos to you and to the budding scientists and engineers you are inspiring.
What I'd really like to see is fully integrated heat management in homes. One big ole heat pump, and a manifold to direct hot and cold water. Hook up your fridge, pool heater, ac, heat, solar, battery packs, everything.
I've been thinking about this as well, instead of solar panels we could install solar absorption panels and radiative sky cooling panels all over the roof, but I don't know a reliable way to toggle the panels on and off, without having to replace mechanical parts a lot
In combination with more efficiently insulated homes, the energy required to moderate the temperature of the home would drop and less panels would be needed
I think another useful tool is window treatments. I'm thinking things like: An external insulated & heat absorbent window shutter for cooler weather, and a passive cooling film for warm weather which reflects IR and heat and radiates the energy it does absorb into the sky If this kind of thing is possible it would help even more
@@Kavukamari if you live about halfway into the southern or northern hemisphere such that sun somes in at about a 45 degrees angle, you could build and position your house such that one side of the roof is getting sunlight dead on (at midday, the sun would still cross the sky) while the other side of the roof is in perpetual darkness since the sunlight would be parallel to the other side of the roof, though the wobble of the earth might expose it to light if you aren't careful. Then you could have ideally placed and oriented photovoltaic/thermal/hybrid panels on one side of the roof, and passively radiative panels on the other side that could provide cooling power in broad daylight since they are always in the shade (though if you are trying to rejectheat to space, you'd either need to ensure nothing would radiate heat at them, or you'd need the radiative panels built as staircase structure with protectivs walls to prevent radiant heat from trees warming them up too much, or some other structure.) The closer you are to the equator the more awkward the angle on your roof you'd need, with being at the equator resulting in a flat roof with radiative panels on the walls. You'd be building a roof that peaks with a 90 degree angle, then adjusting the orientation of the roof (allowing one side to get longer/shorter than the other) such that sunlight will almost always hit on one side dead on at midday, and will always come in parallel to the panels on the other side of the roof (missing all of them). Then you would only have the issue of the "solar" side of the roof not doing anything at night. But if you cooled the panels with water (providing hot water during the day), then at night you could possibly use the panels as additional radiators (though not as efficient as the ones on the other side of the roof).
I really love the idea of thermal electric combined solar panels. You can have water run through the panels, cooling them down increasing their efficiency, and use that to heat your pool, or shower water, (with a heatpump) Thermal pvt panels are slowly happening, and although slightly more expensive, can be especially useful on a small roof where more cheap panels are not possible.
Thermal electric panels are also called hybrid panels in some markets. I think they're a great idea. Presumably you could use a heat exchanger with them and use that warmth to pre warm your running hot water for shower etc.
i get that by introducing an MPPT (Maximum Power Point Tracker) you introduce a blackbox, however the MPP is temperature dependent, so in your test without air cooling the power delivered by the panel is actually lower than optimal. which biases your setup more towards the air cooled test. That being said with or without MPPT cooling the panel will always make sense from an efficiency perspective. Love your videos
yes, Vmpp decreases linearly with temperature. So the load impedance should be decreased to get the most out of the module at higher temperatures. Once the panel had heated up to the new steady state temperature, he should of measured the IV curve of the panel with something like a PV Analyzer and then changed the load impedance for the new temperature. The test isn't really fair otherwise.
Of course almost everybody nowadays uses MPPT to efficiently adapt the panels to the load because most inverters use this technology. But the fact remains, that any solar panel's efficiency is decreasing at higher temperatures. This effect is not very different for all the panel brands on the market. It was explained in this video that for this demonstration MPPT was not used on purpose because the ups and downs of MPPT regulation could disturb the measurement. In a real solar power generator the positive effects of MPPT and panel cooling add up. I think, using MPPT for this test would better show the effect of cooling in real life because disturbances of the power measurement caused by MPPT might be less than expected. The influence of temperature on Impp and Vmpp should not be neglected in this test.
@@thomasschmidt9264 I believe you missunderstood me. if MPP is achieved with a 7ohm termination @20°C then you are not at MPP anymore if you increase temperature. Therefore this experiment favours the cooled measurement because you are closer to 20° and therefore closer to MPP
@@SuperBiologe I corrected my text. As Vmpp and Impp change with temperature there might be a change of the optimum termination even the irradiation doesn't change. So the use of MPPT for this test would be better.
Thank you for the solar panel video. I've been in the process of installing, designing, modifying my solar power system, batteries included. Please make more solar power videos and solar panel videos. I enjoy how you give examples and instructions on how your test are performed. You are a smart man.
If I heard correctly you gained 5 watts while losing 3 watts. This was in full sun with zero clouds. If it was cloudy you still lose 3 watts in cooling fans, but do you still gain 5 watts? I’m guessing no. Great video. I like the use of the square casting shadow to find perfect angle
I see one more gap in the measurments. The system in the back of the pannel possibly might keep panel hotter than without it. Maybe without the whole equipment, the max temperature might be lower, and then he is not gaining 5 watts but for example 4 watts.
@@wrobewo2 It's almost guaranteed that enclosing the panel back will limit convective cooling, and thus produce higher panel temperatures when the fan is off. The fundamental point he makes about active cooling is still likely valid. As he points out, the very small scale of the test also means that the cost of cooling is unrealistic. The video is great, but a more complete exploration of a full scale solar system would be informative.
How about using the 'waste' heat for drying the dessicant in your alternative air conditioner? I would love to see you do that as a video (including analysis of the overall system power consumption, etc.).
This is by far the best channel on youtube. Your science communication skills are on the same level as Carl Sagan, and the production quality is amazing. These videos provide a very important public service, you and your team deserve to be recognized for what you do. Your videos inspired me to get back into design and sustainable engineering. Thank you!
I wonder if just the heat sinking passively would have relevance 🤔. Of course active would prove better but if passive heat sinking did have a significant gain then it may prove to be useful in certain applications. Would you guys be interested in doing a follow up with just the heatsinks in a passive setup? Just to show hard results and relevance. And thank you btw for your content!
yeah I just thought up of and started experimenting with attaching those thermoelectric generator pad things to the back of some solar panels a couple weeks ago
It would be really cool to see the effects of the air cooling with the solar concentrators installed on the same panel. The temp differential between ambient and the peaked heat from the concentrated panel load may have much higher yields on performance!
Man, you made my day. I've always wondered what the difference is if you add active cooling. We don't have panels yet, but now I have a better idea of what to do about efficiency when we do get them. Thank you.
You can buy a 310W panel for $120. ($0.39 per watt of panel.) Just be real, and buy a an extra 10W of panel for $3.90 instear of spending countless dollars on cooling your panels for 3.5W. Not to mention the noise and failures. Meh.
Love this channel. The way he explains everything definitely inspires people to understand these technologies and encourage others to pursue such sciences.
RUclipsr Robert Murray Smith has an episode that shows how to greatly increase the output of solar cells. One involves amber filters and focusing devices. You should look at the video. It's episode 1664.
Not a dedicated reflector but Out here in new mexico i know a guy has a ground mounted pergola type solar setup hoisted a good 20 feet in the air and the entire roof line is angled. He used bifacial panels and then lined the area around the panels with white gravel and white cement under the pergola. Said he saw a noticable increase in production once he putthe rocks and cement down.
I’d like to see a few more iterations on this idea. I’d love to see temps and wattage of a panel by itself. Then another with the back panel where the fans are mounted to see if passively cooling with just fins had any effect. A modification I’d be interested in seeing would be to use boxed fins with air directed through, and also water directed through fully boxed radiator fins to see if water could carry away more heat than active air cooling. Not sure if a pump could match the efficiency of simple fans. I may try to get a similar setup to try experimenting. I just got panels installed on my roof and would love to extend their lives and make them more efficient.
Fantastic content! Would love to see more on solar efficiency in future videos. Please make some content on tying it all together with something like heat pumps. This channel is one of the best things on YT.
Currently my panels here in the Northeast are putting out 8kW. I want to add more panels/efficiency for those days when we see no sun. Thanks for the videos, they're very informative.
When my wife and I went to Taos NM in 2017 to spend some time learning about Earthships, I suggested that they do this without fans to try to improve their panels. It is always breezy out there and I figured making and attaching fins to the backs of the panels would help dissipate the heat and boost the panel efficiency/increase the longevity. Glad to know it works... too bad they aren't interested in testing and gathering hard data to prove anything.
This takes me back to the video about using reflectors to boost the output from a single solar panel, since one big issue with doing so was that exposing the panel to over twice the amount of sunlight would probably fry it, this seems like it would be a great way to reach the top rated power output even on less than ideal conditions
The benefit demonstrated in your experiment is overstated. The baseline should have been done without the heatsink and shroud. The high temperature may have been artificially high due to the lack of natural convective current on the back side. You could at least test the junction temperature of an unmodified panel in the same conditions with your second unit to confirm the validity of your test method.
Glad to see you back in action! Please take this as positive feedback… you might want to run your audio through a low pass filter to remove the low frequencies that the wind or moving around is causing. Watching you video on my surround sound system causes my house to shake! Thank you. Keep them coming!
@@MakersAcres I have specialized audio equipment configurations for each video I watch within my facility that hosts many pre-calibrated rooms with specific environment controlled tech custom tuned for each of these videos... all equipped with a deluxe LazyBoy recliner and haptic suit for maximum enjoyment. Only the finest. ; )
MTBF would be my primary argument against adding dc/dc voltage regulators, fans and heat sinking. I'd be curious to see the performance uplift of just adding the heatsink without the backplate and fans. Either way, excellent bit of content as always!
Love this type of detailed testing an explaining. Keep it up. Testing all the things I’ve wanted to test but haven’t been able to because of time and money constraints.
Water heating type of these panels are pretty popular in the Mediterranean. We had one installed about 15 years ago. The water was so warm that I'd had to introduce cold water at the combination tap.
As always a well made video with proper physiks. Living in an area with moderate temperaturs I'm currently leaning more towards just adding more panels instead of optimizing them for peak power. I have issues with not having enough power in the winter and low lights (panels are cold there anyway). As I can't store the power long enough to be usefull. In the summer the panels produce more than enough power already. And the roof is not full yet ;). Also moving parts are not what I like to have (but that is just me). I clearly see areas with limited space and enough storage to benefit exactly from what you tried there.
Word class methodology. Showing the meters clearly and continuously is virtually unseen on youtube. Thanks! love how realistic and well thought the analysis is.
I think you can make it even more efficient.. You could attach a small electric water vapor thingy to the back, that blows out a little bit of water every so often, at the back of the solar panel, covering the inside of the back in a thin layer of water.. this, together with the fans, would cool off the back of the panel even more, due to evaporative cooling.. It would literally cost almost no extra electricity to add this to the system.
@@rogerphelps9939 depends on what you can use the “hot” water for. I have a two story house with a gas water heater in the basement, and would be surprised if I could bring that heat from the roof to the basement with a net gain. Not saying it isn’t possible, but it seems unlikely for a trickle of warm water.
@@rogerphelps9939 While i agree that circulating water would cool down the panel to a greater extend then water sprayed on the back with air blowing over it, this would most likely take too much power to run.. for this system to work, you would need to use alot of electricity to pump the water around.. you might get around this problem, by having some sort of rain water catcher, that holds onto the water, at a higher elevation then the solar panels, and then slowly releases it down some thin tubing over the course of a hot sunny day.. but if you are circulating the water, you will have to use a pump, and pumping water would most likely cost more electricity then what is gained.. not only that, but the water that is circulating, has to be cooled off somewhere, so you would need something like a radiator with a big enough surface area, to cool the water down, else the water would just heat up slowly.. But if you misted the back of the solar panel with some kind of electric spray bottle or something like that, it would cost almost no extra electricity, and with the fans blowing over the water, it would cause the water to evaporate.. when water evaporates from a surface, the surface cools down a bit.. this is how "swamp coolers" work.. thats why you feel cold air, if you sit infront of a swamp coolers output while your room is hot.. the problem with swamp coolers tho, is that swamp coolers not only cools the air a bit, but they also raise the air humidity quite a bit.. so even if you manage to cool down your room by a few degrees, it wont really help much, since the humidity is higher.. with higher humidity, the "warm feeling" in the room intensifies.. just like when someone puts water on the hot thingy in a sauna.. but this is no problem outside where a solar panel might be located.. outside you just gain the cooling effect on the panel
I really appreciate your videos. You actually build and test the things I just sit around and think about forever stuck in a state of analysis paralysis. I was surprized yesterday how warm the panels are when the ambient air near freezing and the aluminum frame of the panel (black, shoulda been light) is comfortably warm. I just got them this fall and really wonder what the temp of that frame is going to be in August? The cats sure seem to like to hang out behind them on a chilly morning. One thing not mentioned is the reasonably expected lifespan of the fan motors. If you installed 100 of those fans, how many of them would not have seized bearings in 10 years? I wonder if electrostatically charging the air with HV, moving air with no moving parts might be a better option? Dyson fan for clues. I think closed circuit liquid cooling is where it is at, much easier to utilize that collected heat elsewhere which could be considerable on many sq ft of panels. After watching your solar water heater/PV drag race, I'm sure you are readily aware of the heat potential, well over half the radiant energy caught by that PV panel becomes heat at the panel that must be convected or radiated or in the case of liquid cooling, conducted away. You would have a hybrid solar water heater/PV that makes flowing electrons too! Maybe use a sheet of coroplast(styrene) or polycarbonate greenhouse panel to make a heat exchanger that can be glued on the back face of the panel, would be pretty easy to fashion multiple circuits with and exacto and a soldering iron if that seemed beneficial. If you used silane for glue it could be easily reversible to not mess up your panel if it doesnt work out. Coroplast can be purchased with a decent layer of thermal insulation sandwiched on, and greenhouse panels can be purchased that have 2 or 3 layers deep for insulation purposes. Thanks for doing and sharing what you learned.
I had a similar thought about the fans needing to be replaced multiple times through the panel lifetime. There's also the added cost of the heat fins and back panels. Also I don't believe the Dyson fans are electrostatic. They have a fan in the base and the airflow is directed up to the manifold in the top section. But I like the idea of cooling with no moving parts.
I have computer fans stacked about an arm's length from early 00 and the fans still work well. Most of these have ran through at least 1 if not 2 or 3 versions of Windows. The fans outlasted the system being relevant in most scenarios. I am not positive to the max life of solar cells but you could not buy any rated past 10yrs before recently if that has even changed. The clear coating on the cells will have to be redone if they are even still functionally efficient enough to run as a modern system after 10yrs of improvements to material research. Plan the purchase I guess for a summary and look at the lifespans on your investments in cells.
@@rallyfeind You are way off on solar cells. Panels last basically forever and 25 year warranties guaranteeing 90%+ performance after 25 years are industry standard. But most panels are still working just fine after 30+ years. They have glass covering them, not clear coat. Sure sometimes electric fans last forever, electric motors are very simple and tend to have very little wear in operation. But you're missing the point that these would be outside and exposed to the elements and running constantly 24/7 in hot weather. Then you add in that there will need to be 3 per panel, and with my solar array that would be 84 fans. I'd be replacing fans pretty regularly instead of just having a maintenance free array. I think the extra money and effort would be better spent on a few additional panels. And this simple calculation is why nobody really bothers with active cooling of solar arrays.
@@CheddarKungPao Neat. You spent way to much effort to explain something has changed. You didn't tell me how or why like you know only that you are aware of numbers as they stand today. Thank you for the update to the standards without any insights beyond saying that I was outdated in info. Good talk though. Oh can you send me a link for hail-proof glass they are using because that is something I would love to get since I live in a tornado heavy area and hail is inevitable not just possible.
You could improve things significantly with a fluorescent polyethylene film over the panel to absorb UV and re-radiate the energy at visible light spectra the panel can use. This will also stop IR and UV frequencies heating the panel. And double the surface area available for your air cooling, as you can pass air through the cavity on the front as well as behind the panels.
I must admit - when he was talking about spectra I thought we were about to hear about a filter/reflective coating he was experimenting with. Active cooling and major modifications sounds more expensive than just adding another panel to the array for the extra power.
How much attenuation of the light at critical wavelengths occur, when using such a polythene sheet, wavelengths which are used by the panel to create electricity?
@@deang5622 you may lose 5%. But Infrared is blocked very effectively, and the fluorescence can boost output by over 30%. Robert Murray Smith on RUclips TnT demonstrated it with a green leaf smoothy. Blending up some green leaves, and making a chlorophyll dye. Chlorophyll is fluorescent. Even soaking a piece of paper in the dye and putting it over the panel improved it's output significantly. Though chlorophyll is degraded by UV, so not the best choice.
A really interesting episode. My only problem with the power differential was that the baseline was the modified panel with a mostly enclosed back. Are the aluminium fins compensating for this passive airflow that would otherwise keep the panels cool?
That is a great point, he needed to do the baseline with an open panel, not the one set up for passive cooling I wonder what the baseline of the open back panel is?
Love this- absolutely bs-free experimental set-up- both as a learning exercise and more importantly a platform for playing around yourself. These types of things ALWAYS seem to leave out critical details (as you alluded to with the Rice paper on graphene) that are obvious [only] when you actually get 'burned'.
Great video! Very well explained and interesting topic, a small correction in the manufacturing. The vast majority of solar cells today are made by starting with a P-type silicon wafer, and then doping that from the outside by hot gas diffusion, greating the P-N junction. The front and back electrical contacts are usually applied as a solder paste, and then baked in an oven. On the back, an aluminium paste is also applied to create a very heavily P-doped layer, which help reduce carrier recombination, and increases the efficiency. It is usually only 2nd and 3rd gen solar cells that start with a substrate, and then deposit the thinner layers on top, as this is a much more expensive process.
I would love for there to be a solar powered solar cell manufacturer, but as far as I know there isn't any of those around. Producing solar cells is a huge multistep process, usually different companies specialize in different areas. Which research paper are you looking for?
I have learned something watching this channel since the beginning, whatever comes out of this man's mouth you can take it to the bank.i love learning and I appreciate this channel and all that you share with us.
Great video and channel! I'd be curious to add into the wear and tear of fans, replacements etc into the total life cycle cost. Depending on the setup storm's may not make having small computer fans very beneficial. Still, if a company looks closely at this like the one example you gave I'm sure they can find better fan designs that are more storm resistant instead of off the shelf computer fans.
Any chance you could show a better picture of how you attached the heat sinks to the back of the panel? Usually there is a vinyl cover on the back of the panel, I am guessing you removed that and put the heat sinks right up against the panel? Any thoughts on keeping moisture out? Also have any thoughts on how to actively cool bi-facial panels? Very cool method of cooling the panels.
Oof! active cooling on a bi-facial would be a PITA since you don't want to block the reflected light from hitting the backside of the panel. Maybe using the water trickle method on the top side as he mentioned and simply having a set of fans blowing across the back of the panel.
@@michiganengineer8621 the trickle method would probably be the best bet. Could possibly use a clear channel and force air through that. Could allow for light to go through and channel air. As far as removing the vinyl backing, I wonder what effect that would have for allowing moisture to more easily access the back of the panel. Perhaps if you sandwiched the entire back panel with thermal paste that could prevent moisture intrusion?
@@Runnerb03 For standard panels I'm not sure you'd need to reseal the back, if you did maybe a thin layer of epoxy resin or a conformal coating after the heatsinks have been bonded to the panel. With bi-facial panels I'm pretty sure the backside is already sealed as well as the top.
Firstly. ALWAYS top notch content. No one does it better. I had 3 ideas after watching this. 1) why not use Thermo Electric Cells adhered to the right angle heat syncs? Heat on one side cooler on the other... maybe enough to run the fans. 2) If a water sync like a lake is not available... consider using the trick of digging down 4-6 feet and burying pipe. Get some precooled air. 3) the approach using the buried pipe can be done using convection heating to move the air without power depending on where is installed.
The thermoelectric generators are very inefficient and will lower the heat removal from the PV panels. The net result is an overall decrease in system efficiency.
There is another cost consideration. How much cost is the cooling system adding overall? Because if I just want 5% more power I could add 5% more panels (assuming there is available space). As much as I appreciate the efficiency and potential life extension of your system, I generally favour the KISS principle. Fewer moving parts is almost always a good idea, especially on an installation with an expected lifespan of 20 years or more. Finally, to make the most of your system you would probably need to add a temperature monitoring system for each panel so that you can identify any problems with the fans and know when to service them. Maybe there is a better way to use passive cooling to keep the system simpler and without moving parts? Could be the ideal compromise. Enjoyed the video, btw!
That's legitimately a nonargument. The cost of a couple fans and some aluminium sheets is nearly nothing compared to the panels and installation. You're also COMPLETELY ignoring the environmental effects of not having to produce even more garbage. A good quality fan can last several decades, the same as a solar panel.
@@Gabu_ You are talking about the environmental effects of "producing more garbage" yet you are suggesting to add a ton of fans, aluminium fins, fan controllers and power supplies, other mounting hardware, etc. You are contradicting yourself.
@@ABC-rh7zc I'm not contradicting myself, you're just clearly completely unqualified to comment about this topic. Recycling or reusing aluminium is easy and cheap. Fans are mostly made of empty space, cheap and easy to discard properly. Solar panels use a shit ton of energy to produce and contain heavy metals, toxic pollutants. Which do you think makes more sense to preserve for as long as possible?
I had similar issues. One thing that is kind of ignored, which is understandable, not everyone lives in a hot country. The roof surface temperature will be 50°c to 80°c in summer. DC fans generally don’t work well at such high temperatures in a 24/7 environment that wouldn’t require looking after. DC fans are cheap, but if they have to be constantly replaced every 1-2 years, the amount of efficiency gains become a headache. We have flat roof over here, but other countries use slanted roof structure. Servicing, repairing will be immensely troublesome. Plus we get dust storms, dc wire connections will break over time. Had the heat sink worked, that would have been great. Using cold water is an option, but our water tank is usually on the roof, that is already hot. Folks who have underground water tanks will have to live with hot water coming out of the cold tap. Usual panel size is about 3’ x 6’~7’. Those metal sheets may stop working as effective heat sinks. Especially during winters. We have to remember, best testing conditions are done around 22°c with a light cool breeze. If the air temperature is 10°c and panels are warmed up to 18°c because of the sun. This active cooling will cool the panels down and make them more inefficient. USA is quite backwards in solar technology, bifacial panels solve this issue significantly. Having a white heat sink coated roof works out really well well. Still not sure if worth the investment to go this route. Sorry for the message appearing after a year 😁
I remember nighthawk in light showed a really efficient way to always center the solar panel with 4 slights smaller ones at each of the edges connected to motors. It would seem weird but if you can get small enough panels it could work really well.
The ones at the edges are not really solar panels, they're photoresistive cells that change resistance depending on light. A full tracking system like that is not practical for reliability and maintenance cost reasons. It would also be easier to just use the internet to look up the position of the sun based on location, instead of actively tracking it
@@signalworks I drive past a large scale commercial solar farm occasionally for work, and I noticed the rows of panels were all facing northeast in the morning. Weird direction for central IL, and I assumed maybe they were working on them and somehow had flipped the panels to 'shut them off' so to speak. Later that day (late afternoon) driving past them they were flipped to the southwest and you could see the mechanism that flips entire rows as a whole. Point is some commercial operations are active tracking at least in a single axis so it must be economical on some scale.
This absolutely explains my recent frustration 😤 I have a 1800watts panel array and I have noticed drastic drop in watt output within a year, it is currently given me 400watts at peak value as opposed to 900+watts when it was first installed. I have called the technicians many times to come and test why and explain, they all have no idea why. But this video gives me an understanding why. Thank you, subscribing...
That sounds like a big drop for one year, even allowing for the temperature effect. You might check whether there is any shadowing of ANY part of the array. The combined output can be significantly decreased by a weak panel. You might also ask if they checked the output of each panel. The same effect can be caused by a bad panel. In one year, you might still be under a warranty.
Thank you for further clarity. The difference is really much for 1 year. I believe a bad panel is also causing this. I will request for a thorough test of each panel and have any bad one replaced. Thank you
An interesting test that comes with some design flaws that could greatly improve the system, and a series of variables that compound my interest. 1) Fan alignment. You have top mounted intake fans, which is generally a bad location since hot air rises and you fight the natural convection. The panels should be flipped upside down. You also aim the fans so they blow at a nearby surface (the back of the panel), rather than in the direction of desired flow, thereby decreasing CFM due to the pressure losses. Bottom mount the fans, perpendicular to the panel with ducted shrouds to focus the air down into the heatsink channels. 2) Convection has a worse heat exchange than convection. While you state that it doesn't make sense for your setup, I imagine economics of scale against a say 8x3 panel array would improve the numbers on running a pump and radiator. 3) Useful work. Most buildings, be it commercial, industrial, or residential, require how water. Pumping 40° coolant through a heat exchanger in a modified heat-pump style home water heater reduces the workload for a radiator, and re-coops lost power to running the water heater. 4) Temperature delta. While 3W vs 10W to run a few fans is a better solution than 30W vs 10W, lower latitude areas also have worse temperature deltas than NE: Dropping the panel to 30°C isn't a realistic option when outside ambient is already 48°C. A heat pump is a far more efficient for moving heat than ambient convection in high temperature areas, regardless of variables other than scale.
Definitely interesting any efficiency boost to solar without massively increasing cost seems worth it. I would be curious to see the temp difference with the back panel with fans removed rather than just off.
The fans alone will massively increase cost. The simple fact is solar panels are about 1$ per watt these days, and it's going to be impossible to find a high duty cycle fan, that can survive high temps, outside, that will increase efficiency by 1 watt for each dollar spend on the fan. Then consider those fans absolutely will need maintenance, and it's all the sudden not a good idea.
This is cool, but need more data! Strait on with the 68% sun, 3 watts in gave 5 out. But do the fans still help produce more then they use at oblique angles? If you can either test different angles to find the tipping point where the fans stop helping (less then 3watt boost) - or do a full day test facing south at your ideal angle upward (probably 35ish) to get the average for us who don't have panel movers. Would really help give us the full picture. Also how about a liquid to liquid heat exchanger; setup with antifreeze on the roof side and preheat cold water into hot water heater on the other side. - Cool your panels and preheat water at the same time?
The main issue I see here is that the cost to add the fans and metal to the panel. Sure you gain 2 watts of power but how long would it take to recoup the cost of the additional materials. The second part would be that those fans will most likely go fail somewhere between 5-10 years so the cost of replacing the fans needs to be factored as well.
I really enjoy these energy videos. I've been way ahead of you on this so far. If you store the extracted heat in an underground insulated tank/pool, you're offsetting your home heating costs in the winter, while chilling your fluid for panel cooling in the summer. You can also run a closed loop ethylene glycol loop into an aquifer for a few hundred dollars and only run it's pump when ambient temps are over 30-35F. It takes very little energy to move fluid in a loop.
Thank you for excellent explanation for a total newbie. This is so rarely seen this days - technical topics explained with easy to get language without excessive jargon. Thank you for sharing your knowledge and experience!!! Keep on doing!
Always enjoy your practical experiments and analysis, very interested to see net gain in relatively temperate climates, I’ve been thinking about this for some time but hadn’t considered your approach for homemade heatsink which had made the capital cost prohibitive from my perspective. I do think the heat recovery point you made at the end makes the cost benefit case more attractive even for a domestic Instalation if you can divert that heat through and existing air source heat pump and into your hot water (in theory this would increase efficiency/reduce cost of producing hot water). Nice job 👍👍👍
Always solid content and we are getting it from a first rate technical instructor. I believe I have watched all but 2-3 of your presentations. Congrats ~ Allan J
I've wondered. Can't you collect the heat from the panel and use it to heat your house in the winter time? Perhaps you could also use this heat combined with a heat pump to pump heat into the ground during the summer, then extract that heat in the winter. AKA stabilize the ground as geothermal heat pumps tend to work well when they start, but it takes around 8 years fore the ground to stabilize. At that point the heat pump looses a lot of it's performance.
I imagine the only effective way to heat your house with this would be through a heat pump. The air isn't going to be hot enough to directly pump into your house (if your displacing 20c air with 15c air, it's going to be a loss) You could duct the air into a air exchange heat pump, but you would need to redirect it based on if your heating, or cooling your house (heating the outside unit is good for when your heating your house, but bad for when your cooling your house). My guess at the best way to utilize the heat would be pre-warming the water coming into your house for your hot water tank. The only question then is if it's enough flow to keep the panels cool, the useful heat gained may be outweighed by higher panel temperatures.
There are systems that use heat from the sun to collect heat and transfer it in doors, but from what i've heard they are quite expensive. Its usually an array of glass tubes filled with glycol that gets pumped in to dump heat into a water heater. if you are heating a small enough space, have really good insulation and are already taking advantage of passive solar heating in the design of the building you might get away with using only radiant heating to keep the building warm in the winter. SunMaxx solar has some kits if you want to see what they look like. I've heard they are a pain to maintain though. if the pump fails for example, you can get into a situation where the system gets too hot and will get damaged relatively quickly.
@@Errzman They did some solar hot water heater stuff in this video ruclips.net/video/5g5PW78XMSo/видео.html the vacuum tubes are not great, you can get a much more reliable system for low $.
Great video as always! Would it be possible to filter out the wavelengths that only add to heating on the front surface of the solar panel via reflection?
I think he mentioned that in a video before. I heard it somewhere. My recollection is that the filtering would lower the input too much to be practical.
A couple things come to mind. First, I'd really like to see the unmodified panel's performance rather than measuring the performance of the panel with heat fins attached but blocked by the outer sheet trapping the heat and not allowing convection heat to flow upwards. I'm speculating that there's no heat sink compound between the fins and the outer sheet of aluminum and just trapping heat inside. With my rooftop solar system on a sunny day, there's significant convection warm air flowing upwards between the panels and the roof deck that whisk away the heat. Second, the longevity of the fans vs the solar panels. How often do they need replacing? Third, what is the performance look like with the air heat sink attached but the rear panel removed so that it can just dissipate into the open air. I would guess that would be the best of both worlds. More surface area without adding mechanical devices to the mix.
The back of the panel is shiny. Shiny equals low emissivity. It needs to be black if it is looking at grass! There is also room to place a reflective surface behind the array to reflect the sky. The sky is transparent to IR at 8µ to 15µ and acts as a super cool heat dump.
If the people woult take a IR kitchen thermometer and aim it in a night with no clouds up outside, they would be shocked. MINUS 50-60 degres Celsius. First i did not get it ... (Think this would also make a good short learning video for Tech Ingrediens ?)
Also, flood systems are more effective than you elude to due to evaporation. However they have their own issues, such as mineral deposit build-up over time - especially in areas with hard water.
I was wondering if you could convection cool the sun panel. Add an insulated chimney on top to create stronger draft. In fact you could do an entire video of whether is there a limit to that kind of cooling
It all comes down to the cost of the cooling, 5 watts will make $1 of electricity in about 1 year, solar panels last max 30 years So if you cooling system gains 5 watts, 6 equivalent hours per day, for 30 years, your cooling system cannot cost more than $30 per 100w to just break even And few people are willing to put money into an investment that doesnt pay back in 5 to 10 years. And that's if nothing breaks, gets blown down, damaged by contractors, etc.
@@jaycweingardt11 Since you replied toy comment I feel entitled to intrude: Note it's around 5 watts in the video for a single panel. Still marginally beneficial but from a more level ground.
@@LiviuGelea Or consider the additional wattage gained from cooling and compare the cost of the cooling system (including maintenance over 30 years) against simply adding the equivalent wattage in additional panels without any cooling. Well, I can already tell you the answer... it is far more economic to simply add more panels to the system than it is to try to cool an installation.
I was wondering the same thing. As stated below by others, I'm also not the biggest fan of using fans, because of the added complexity. However, if there were to be a simple, low cost solution that would last the lifetime of the panels that would be striking gold. In the solar panel installation on our home there are gaps between the panels. I can't help but wonder if it would have been more effective to seal every gap, and only leave the gaps on top of the rows of panels and the bottom. This would create a chimney almost for free. The top panels would be warmer than the bottom panels (so parallel connection would be required), but you would create a higher airflow, basically for free. Especially on less windy days this might actually result in a higher heat dissipation. I'm not sure though, it's hard to get an intuition if the pro's would outweigh the cons.
Excellent video! Thinking of a solar project in the spring, Lots of helpful data. Very interesting how you "play-out" the various arguments for/against, plus/minus. I'm a Broadcast Engineer and my wife has a degree in English. You were able to hold her attention too!! Many Thanks!
In a previous video you showed a set of DIY wing reflectors that helped increase how many photons the panel gets, I imagine those would have the same effect as being in an area like the southwest of raising panel temps. It would be interesting to see the effect of that active cooled panel with the wing reflectors attached to see how much more of a difference it makes.
Was thinking exactly the same. Run a pipe system on the back of each panel, connected to a manifold, and have the whole system connected to a water basin.
Thank you sir, very well done. I was inspired by your Peltier cooler two years ago and decided to build our own for our insulated battery enclosure. Both heats and cools based on internal temp. Now I must thank you again, our East-West Facing system called the SA4 acts very much like a greenhouse in summer. Going forward will install a fan on one of the ends of the array to allow fresh air to flow under the panels when ambient temperature rises above 20 degrees C. This will surely increase gains, and thankfully our Grid Tie Inverters all come with a 120V outlet at source to power the fan. Keep up the great content, as a solar installer, it's a pleasure seeing these experiments.
I really enjoy these how-to engineering videos. Just got off my roof checking temperature of panels and found the heat around the black asphalt shingle roof was hotter that the pv solar panel. The ambient was 65°F, panel had gotten to 105°F by 10am, and black shingles were already over 135°F. Behind the panel the shaded shingle roof was 90°F! So my roof heating is going to be more of a problem than I expected.
A clear scientific demonstration of the value of keeping the solar panel temperature in a safe range. Thank you🌹. The refrigerator runs on 100 watts power through the day. A 12 volt 8A panel can supply this power for 6-8 hours a day for twenty years. This greatly exceeds the cost of the panel. So it's a great saving. No power failure. Safe.
Earlier last year i convinced my dad to let me install a DIY pool-water circulating system on his 16kW panels in Spain. Panels temps dropped from 85°C at 30°C ambient to about 45-50°C. Average power output on a cloud free day jumped about 17% in addition to eliminating the pool heater in spring and fall. Since this house is completely off-grid, the savings in diesel already made up for the $800 cost.
The system is not perfect and was more of a prototype that worked too good to tear it down. Super cheap plastic sheets glued on the back of the panels with about 1cm gap and sealed on all four sides. Fittings are epoxied straight onto the plastic. Water flows in parallel through all panels, two redundant overpowered pumps are controlled by an ESP32 with Wifi for fault notification and temp measurements. Next upgrade would be a water to water heat exchanger to be able to run automotive coolant. In theory i could push air through the same pipe when pool-temps get to high, might test that this year
Nice
This is the way.
In the video setup, if you lose power to the fans, or the fans fail, you'll cook the panel fast. With a water cooling loop, you still have air flow if things break. And, over a long enough timeline, something will fail.
I have an 18kw system that I DIY'ed, with half mounted on a roof, half on the ground. I water cooled a 6kw section of the array and am seeing similar results. The heat is dumped into the ground. The pump is powered by a panel that was badly damaged during shipping, but still makes power.
@@ur_quainmaster7901 Not to mention how long do those small fans cost? And how much work would be involved in pulling a panel out of a large roof mounted array, to replace a fan? I think a much better way to go about this if you have the land area, is just build a ground mount array, so the panels always have free air flow around them, and makes the array itself easier to service, and also not get in the way of roof repairs. But if you don't have the land space, and/or don't want the eyesore of a huge ground mount array, then mounting on the roof and using the waste heat to heat water for a pool, showers etc, is a very good idea.
@@ur_quainmaster7901 I assume they would connect the fans across the panel with a voltage regulator in practice so that never happens, if the panel is hot it's making power.
How does this effect pool water temp in the summer?
Guys please take the time to appreciate what this channel is doing. They are producing top notch content, super educational, very well produced and they at no point read any sponsored ads, they don't ask for you to join their Patreon, they don't sell you merchandise, this is unheard of in the world we live today. So much effort goes into these videos and I'm always blown away how sincerely the content is delivered, if you haven't subscribed, just click a button real quick and forget about it, or at the very least leave a like, the value proposition is very fair.
Couldn’t agree more!
Wonder how much money they are getting from country kitchen on this video.
isn't it their job to advertise for their own patreon?
@@katiebarber407 Certainly, but there's a link. No need to turn it onto the total begathon some other channels do.
They were supposedly going to sell their thermal paste. I put in an order and heard nothing. No communication of any kind. I eventually had to do a charge back through PayPal.
I agree this man puts out some of the best content out there for useful scientific information and self edification. I always look forward to his new content and have learned so much from his work. I dont know his name and I should but I'd like to thank him right now for all of his effort and knowledge that is so generously given to us watching. Thank you Sir! So nice to know that there are still those out there that teach just to enrich the lives of their fellow man. Bravo Sir.
This channel is a treasure!! Such diligence is so rare on RUclips, thank you for your videos!
Agree- outside of automotive review channels, etc, this channel and Project Farm for comparisons are among my tops.
This is truly a scientific good old style educational channel. The presenter shows a rare combination of beautifull understandable English - important for foreign listeners, huge knowledge and intelligence.
He is the teacher I wish I had for applied physics in vocational school classes.
@@That_Handle this channel's really good when he sticks to science
Felix, if you like this channel, you may also like Project Farm. Same kind of diligence applied to somewhat less technical matters. Cheers!
The ONLY thing I could suggest is to run a side by side comparison of the two identical panels, one actively cooled, and one not. I'd like to see data logging and graphing the way Matthias Wandell does. Face them due south and let them run for a full 12 hours.
I’d like to see this as well. During the initial control test measurements, I wondered if the unpowered cooling system has a greater temperature than the unmodified PV panel.
Great suggestion!
@@jasonwisser3253 It's unlikely that the modified PV is hotter than the unmodified one.
They receive the same number of photons that create the waste heat this modification is addressing.
Yes, and drive the fans by the produced energy off of the cooled solar panel through a buck converter set at the fans most efficient voltage. Adding any external power through a power supply does not make sense for a scientific efficiency measurement.
@@jasonwisser3253 Good point. Tough to tell. The added heatsinks on the back may have even lowered the temperature of the panel when the cooling was disabled. It's not a perfect test.
Love it! In my 4KW PV array in upstate New York, I was distraught in winter when an inch of snow dropped output to zero. I disconnected the array from the Controller, and fed pulsating DC from a 240 volt bridge rectifier to the panels. In an hour, enough of the snow melted to begin self-defrosting. Reconnected the controller and produced power the rest of the day instead of zero power.
Wish that switching was an option of the controller! Could easily be fully automatic.
I love this guy. He takes these tiny details in his work and takes it far beyond than I can even imagine
I like what you have done to improve solar efficiency.
30 years ago I started adding solar pool heating strip to the back of panels. It has 10 pipes moulded in a rubber strip. Usually glued to the roof to heat a pool, it is easy to serpentine it across a row of panels 3 times and slitting it at the turn-rounds.
A small 12 panel driving a 12v solar HW-heating pump will auto speed-control according to the sun on the panel and thus be self compensating.
Air cooling is poor compared to water and more than one fan is a big no, no, as one fan will pull through the others.
You can always dump the heat into a pool or a heat pump via a car radiator, so its not necessarily wasted.
literally the best tech guy on youtube, i dare anyone to prove me wrong
You took the words right out of my mouth. Just when I think of something to ask, he answers it like he was reading my mind.
some people just call it being thorough. it's amazing how capitalism has trained us to think that simply being thorough is somehow going above and beyond. it's also known as doing something right
30 years ago I was living in my RV in the Colorado mountains for a couple of years and getting my electrical power from PV panels. Plus I was spending my days designing a MPPT charge controller, so I spent a whole lot of time thinking about PV panels. You covered everything I experimented with, as well as contemplated regarding thermal management and optimization with the exception of reflectors in low light situations. And the use of reflectors in normal sun was something you have covered in the past. So well done. Thanks for educating many people regarding PV's. While PV cell technology is improving every day, the fundamental fact is that nothing beats the basic physics and applications knowledge for getting the most out of PV's, and you are providing it.
Colorful Colorado, all that sunshine, helps improve the output 🌞
is it time to say 'kids these days have it easy!'?=)
@@morkovija old solar panels, PWM charge controllers, hundreds of Lbs of lead acid batteries, incandescent lights...
Frankly, I don't think a 10 minute test (not to mention with active tracking) shows ANYTHING. All we really "learned" is what we already knew, which is that fans move air.
@@tarstarkusz We learned that at that small scale, we can gain more output than we are taking out. We learned it is feasible enough to try further, longer, and maybe more costly scenarios.
I absolutely love this channel. Can't get enough of the discussions and the experiments. I'm thinking about how to apply these ideas to my practical life and as a nerd, I'm all in. But as a consumer, I'd probably just buy more solar panels to get more output rather than attempt to make them more efficient. Assuming I had the space to put them somewhere, of course.
1:05 No one really does that anymore... For monocrystalline solar cells like the one you're holding, you start with a doped silicon wafer. On the front side, you would texture the surface and typically heavily dope it with phosphorus and then throw on like 80 nm of Silicon Nitride for passivation and antireflection. On the back you would just screen print an aluminum rich paste for the rear contact (Ag on the front). After the printing, you send it into a belt furnace (glorified pizza oven) at 700-800 C which burns off the organic binders in the pastes and causes the metal to contact the wafer. On the back, the aluminum actually forms a eutectic alloy with silicon that assists carrier collection.
Let me know if you want more deets.
Interesting. Things change so quickly I couldn't make a youtube video ever without fear of posts like this lol
Sounds like someone working in panel fabbing
His explanation made it sound like a diode lol
@@sf4137 We make cells lol.
@@yun-z Yeah, interesting thing is thin film silicon solar cells fromm like the 90s used to kinda be made like that.
i still have a hard time understanding why this channel doesnt have 6 million + subscribers already. no doubt one of my favorite channels of all time.
Yes it's high quality output every drop and the person who makes and does the demonstrations is such a good speaker and character. I like the guy and i don't actually know him, he is personable
Because ppl need to think when watching the videos and.ppl don't like that, hence they use TikTok and the like, easier entertainment
I agree. This well presented content uses the scientific method and rational thinking for its conclusions. No hype, no BS. He takes the viewer on a logical journey with a payoff in the end. Just look around you at the average person and it's easy to conclude that they are looking for something else. Keep up the good work, we'll be watching!
No g string butt shaking 😮
@@chiphill4856 No matter how much I like this channel, the content doesn't make my day in the same way as waching a video of a cat falling down the stairs...
On my RV I have considered installing a copper spiral on the back of the panel to act as a hot water maker. After seeing your results I imagine it would also be worthwhile as a secondary benefit of cooling the panel and improving efficiency. On an RV or boat everything should have at least 2 uses/benefits.
If you do a copper spiral, you should try to do something to soak up the extra heat as evenly as possible. If other portions of the panel are still super hot, those portions may be a weak link that prevents you from being able to tap into a lot of the extra efficiency you'd gain by cooling the parts in contact with the copper coil. Maybe get a flat sheet of copper that is the same size as the back of your solar panel, then use some plumbing solder to tack down your copper coil to the sheet. Use some thermal grease or compound of some sort between the panel and the copper sheet, as well as between the copper sheet and the copper coil. That way the solder is only needed for securing the coil in a few places.
@@HeyChickens sheet of copper?!?!?!? are you ready to pull out a loan???
@@MR-nl8xr I would certainly NOT buy new copper. I would find an old solar water heater panel that someone was scrapping and buy it from them cheap. A lot of them have a full sheet of fairly thick copper inside that the tubing was soldered to. The solder usually is about oxidized off by the time someone scraps their solar panel, so it shouldn't be too hard to get it off so that you can run your own tubing pattern. The scrap value of a 4'x10' sheet of copper is well under $300.
@@HeyChickens says way under 300 like thats not some ones entire paycheck, and more than most peoples paycheck after bills..
@@neon_Nomad I feel ya, but unfortunately almost all solar water heating or PV panels and accessories are not cheap. It is what it is.
I have 400watts of panels mounted on the top of my motorhome. I was unaware that the heat hurts them like that. I will absolutely be making covers for them for when the motorhome is in storage now. we hit 45 C in the summer where I live. I bet those things are hitting 100 or more in the blazing sun. And if they aren't even doing anything I better have them covered! Thank you for the video! I love learning new stuff!
The panels will likely outlive the Motorhome so perhaps cover the entire vehicle?!
Typically they design these with a 30-50% excess margin built in due to the fact that they do degrade slowly over time. The biggest help will be adding extra batteries to such a system. If your RV can fit an extra 4 or 8 batteries, it's often well worth it versus having to replace the panels in a decade or so.
You know, If every school kid had a teacher like you in every grade we would be in such amazing shape as a nation!
Are you saying that purple hair isn't interested in educating students, except about assorted perversions?
@@hxhdfjifzirstc894 that is one aspect for sure
Indeed. The best I ever got was a few episodes of Watch Mr. Wizard on TV when I was a kid.
We can simplify this even further. His objective approach to thinking about the world makes him an excellent role model. Children need strong role models who figure out solutions to problems.
I teach Grade 1 and I think we should be very aware that the upcoming generation doesn't seem to be interested in projects or hobbies such as these (most parents of these children don't seem to have any interesting hobbies either). This has nothing to do with school either. It seems most people now prefer to watch rather than to do (just as we are doing on this RUclips video).
We need to be engaging children in doing things, rather than watching things. That's my opinion at least. Tech Ingredients does a great job of trying to engage the viewer in practical science (look how engaged the comment section is in every video). My hope is that people leave these RUclips videos and are inspired to figure out problems on their own too.
Instead you have drag queen story hour. Well done.
I always appreciate how rigorous, well thought-out, and well executed your experiments and videos are. Please keep up the good work!
I really like what you guys are doing in terms of your production quality!! IMO Arguably the best content and articulation of such on RUclips.
Keep up the awesome work guys!!
Professor, great video. I love to learn, even at 68 yrs old. I have to say, you’re my go to channel if I want to learn about your projects. This project has really excited me. Thanks for taking your valuable time to teach us.
When I installed my Australian arrays I was tempted by the Dualsun panels using a water loop to dump heat into the 50K liter pool as a heat sink. I think you’ve inspired me to revisit active cooling for the next array to compare performance directly. Maybe I’ll find room for a sunnovate panel too.
Try plumbing the heat exchanger that's connected to an accumulator, similar to an AC or refrigerator set up. This should let you concentrate the heat/waste energy to be converted to something more usable, perhaps captured from a peltier stack.
Sorry if I repeated your thoughts yours sounds good.
DualSun could conceivably work if you could make the hot water output 30°C and not have a legionnaires risk.
Here in Australia we sometimes have forced air ventilation of roof spaces to reduce the heat gain through the ceiling, so in those cases you could even just redirect that existing airflow to behind the panels for an even greater efficiency gain and very low capital outlay. Likewise with air conditioners, commercial buildings usually have about 0.7 air changes per hour, so all that chilled air being discarded could be blown behind the panels.
It would be interesting to see the effect of just the heat sink fins and an open back vs the closed back and fans. I feel like the convective flow over the fins might be enough to tip the energy balance toward the passive design without fans.
My thought too. Additionally you minimize cost, you don't steal any power and you omit any moving parts that would need service and eventually fail.
Passive cooling has a better chance than active cooling. Good fans are freakin expensive, I bet you'd try to save the solar panels by adding fans and end up spending on ton replacing burnt up fans, when you could have just added more panels. Solar panels are too cheap these days to make this stuff make sense. Put as many panels as you can fit on your roof and be done with it, unless you're willing to lower your ROI because it's pet project or whatever.
I spent hours designing a passive solar tracking system that should add 20% to daily solar harvesting, but cost 20-25% additional for the array. In the end, adding 20% more panels with no moving parts was the wiser solution.
Open air natural convection cooling may be a workable thing in higher latitudes, but in lower latitudes, the sun may be directly overhead (or further, towards the poles), and the panels may lie flat. There's no real possibility of natural convection for a panel laying flat - forced convection would be a must-have. And cooling would be even more critical.
For much of summer, the sun is actually a few degrees north of us in Phoenix, AZ (about 33 deg North latitude). Temperatures (in the shade) typically exceed 110°F (43°C) from 11AM to 5PM.
@@brettd5884 Non-tracking, fixed angle systems are set halfway between the summer and winter solstice angles which is fairly close to the local latitude. So Phoenix, AZ would have a fixed angle of roughly 33 degrees.
Rotating and moving up and down to peak the panel output, Plus a passive heat sync is more efficient than putting fans on the back. Most Solar panels are not even pointed directly at the sun for any meaningful amount of time. So, they never see peak efficiency... but for a couple of minutes a day.
We typically just add a little more solar :) Also, it seems like your aluminum backing is trapping hot air causing your starting temperature to be higher than it would with an open back and angled panel.
It doesn't. The uncovered panel is still better than the stock panel.
I continue to be impressed by the editing on these videos especially for the intros. And how long the takes are, it's not easy to do that many lines in a row! Each of these videos is a masterclass, kudos to you and to the budding scientists and engineers you are inspiring.
What I'd really like to see is fully integrated heat management in homes. One big ole heat pump, and a manifold to direct hot and cold water. Hook up your fridge, pool heater, ac, heat, solar, battery packs, everything.
I've been thinking about this as well, instead of solar panels we could install solar absorption panels and radiative sky cooling panels all over the roof, but I don't know a reliable way to toggle the panels on and off, without having to replace mechanical parts a lot
In combination with more efficiently insulated homes, the energy required to moderate the temperature of the home would drop and less panels would be needed
I think another useful tool is window treatments. I'm thinking things like: An external insulated & heat absorbent window shutter for cooler weather, and a passive cooling film for warm weather which reflects IR and heat and radiates the energy it does absorb into the sky
If this kind of thing is possible it would help even more
I'm sure it would sell pretty good. So get a loan and BUILD IT..!
@@Kavukamari if you live about halfway into the southern or northern hemisphere such that sun somes in at about a 45 degrees angle, you could build and position your house such that one side of the roof is getting sunlight dead on (at midday, the sun would still cross the sky) while the other side of the roof is in perpetual darkness since the sunlight would be parallel to the other side of the roof, though the wobble of the earth might expose it to light if you aren't careful. Then you could have ideally placed and oriented photovoltaic/thermal/hybrid panels on one side of the roof, and passively radiative panels on the other side that could provide cooling power in broad daylight since they are always in the shade (though if you are trying to rejectheat to space, you'd either need to ensure nothing would radiate heat at them, or you'd need the radiative panels built as staircase structure with protectivs walls to prevent radiant heat from trees warming them up too much, or some other structure.) The closer you are to the equator the more awkward the angle on your roof you'd need, with being at the equator resulting in a flat roof with radiative panels on the walls. You'd be building a roof that peaks with a 90 degree angle, then adjusting the orientation of the roof (allowing one side to get longer/shorter than the other) such that sunlight will almost always hit on one side dead on at midday, and will always come in parallel to the panels on the other side of the roof (missing all of them). Then you would only have the issue of the "solar" side of the roof not doing anything at night. But if you cooled the panels with water (providing hot water during the day), then at night you could possibly use the panels as additional radiators (though not as efficient as the ones on the other side of the roof).
I really love the idea of thermal electric combined solar panels.
You can have water run through the panels, cooling them down increasing their efficiency, and use that to heat your pool, or shower water, (with a heatpump)
Thermal pvt panels are slowly happening, and although slightly more expensive, can be especially useful on a small roof where more cheap panels are not possible.
Thermal electric panels are also called hybrid panels in some markets. I think they're a great idea.
Presumably you could use a heat exchanger with them and use that warmth to pre warm your running hot water for shower etc.
@@felixokeefe exactly, i have seen a dutch company do that.
Nice part is too that its perfectly quiet instead of a typical condensor.
i get that by introducing an MPPT (Maximum Power Point Tracker) you introduce a blackbox, however the MPP is temperature dependent, so in your test without air cooling the power delivered by the panel is actually lower than optimal. which biases your setup more towards the air cooled test. That being said with or without MPPT cooling the panel will always make sense from an efficiency perspective. Love your videos
yes, Vmpp decreases linearly with temperature. So the load impedance should be decreased to get the most out of the module at higher temperatures. Once the panel had heated up to the new steady state temperature, he should of measured the IV curve of the panel with something like a PV Analyzer and then changed the load impedance for the new temperature. The test isn't really fair otherwise.
Of course almost everybody nowadays uses MPPT to efficiently adapt the panels to the load because most inverters use this technology. But the fact remains, that any solar panel's efficiency is decreasing at higher temperatures. This effect is not very different for all the panel brands on the market. It was explained in this video that for this demonstration MPPT was not used on purpose because the ups and downs of MPPT regulation could disturb the measurement. In a real solar power generator the positive effects of MPPT and panel cooling add up. I think, using MPPT for this test would better show the effect of cooling in real life because disturbances of the power measurement caused by MPPT might be less than expected. The influence of temperature on Impp and Vmpp should not be neglected in this test.
@@thomasschmidt9264 I believe you missunderstood me. if MPP is achieved with a 7ohm termination @20°C then you are not at MPP anymore if you increase temperature. Therefore this experiment favours the cooled measurement because you are closer to 20° and therefore closer to MPP
@@SuperBiologe I corrected my text. As Vmpp and Impp change with temperature there might be a change of the optimum termination even the irradiation doesn't change. So the use of MPPT for this test would be better.
@@thomasschmidt9264 👍
Thank you for the solar panel video. I've been in the process of installing, designing, modifying my solar power system, batteries included. Please make more solar power videos and solar panel videos. I enjoy how you give examples and instructions on how your test are performed. You are a smart man.
If I heard correctly you gained 5 watts while losing 3 watts. This was in full sun with zero clouds. If it was cloudy you still lose 3 watts in cooling fans, but do you still gain 5 watts? I’m guessing no.
Great video. I like the use of the square casting shadow to find perfect angle
He should use a voltage reading to decide to use the cooler. Pretty easy
I see one more gap in the measurments. The system in the back of the pannel possibly might keep panel hotter than without it. Maybe without the whole equipment, the max temperature might be lower, and then he is not gaining 5 watts but for example 4 watts.
@@wrobewo2 It's almost guaranteed that enclosing the panel back will limit convective cooling, and thus produce higher panel temperatures when the fan is off. The fundamental point he makes about active cooling is still likely valid. As he points out, the very small scale of the test also means that the cost of cooling is unrealistic. The video is great, but a more complete exploration of a full scale solar system would be informative.
You could have it set as an automation to turn on only during hot days etc.
@@enkrypt3d or with a thermister.
How about using the 'waste' heat for drying the dessicant in your alternative air conditioner? I would love to see you do that as a video (including analysis of the overall system power consumption, etc.).
@The Tired Horizon on the contrary, it should be quite hot... ;-)
@TheTiredHorizon or standing at the outlet of the air conditioner, inside. :)
Heat is energy.. so it feels bad just letting it out without use.
Could be used for something.. from heating house, heat storage, water or anything
@The Tired Horizon Ye, bi-metal tech is going the right way. But efficiency is still low
@@frosty6960 our guy is testing things .
But is kinda still shortsighted .
Or inefficient .
Thank you AGAIN for taking a complex issue and making it completely understandable. Your hard work isn't overlooked or unappreciated. 😎👍🏼
This is by far the best channel on youtube. Your science communication skills are on the same level as Carl Sagan, and the production quality is amazing. These videos provide a very important public service, you and your team deserve to be recognized for what you do. Your videos inspired me to get back into design and sustainable engineering. Thank you!
Oh boy I was trying to figger out who he reminded me of.....You nailed it !
That really helpful for me. I have to learn new thing here. thank you for your effort doing this experiment for everyone.
I wonder if just the heat sinking passively would have relevance 🤔. Of course active would prove better but if passive heat sinking did have a significant gain then it may prove to be useful in certain applications. Would you guys be interested in doing a follow up with just the heatsinks in a passive setup? Just to show hard results and relevance. And thank you btw for your content!
came here to post that same question. Hopefully they answer it. Passive costs zero watts.
Based on what I've seen in PC hardware, this would be really difficult to pull off. Would love to see TI give it a go though.
I love what you're doing with this channel. Bringing really clear and understandable important information to a wide audience. Big time Kudos!
yeah I just thought up of and started experimenting with attaching those thermoelectric generator pad things to the back of some solar panels a couple weeks ago
It would be really cool to see the effects of the air cooling with the solar concentrators installed on the same panel. The temp differential between ambient and the peaked heat from the concentrated panel load may have much higher yields on performance!
I was thinking that from the start of the video!
Man, you made my day. I've always wondered what the difference is if you add active cooling. We don't have panels yet, but now I have a better idea of what to do about efficiency when we do get them. Thank you.
You can buy a 310W panel for $120. ($0.39 per watt of panel.)
Just be real, and buy a an extra 10W of panel for $3.90 instear of spending countless dollars on cooling your panels for 3.5W. Not to mention the noise and failures. Meh.
lol. I love this channel. the first 2 minutes are unapologetically technical, yet doesn't talk down to the audience at all.
Love this channel. The way he explains everything definitely inspires people to understand these technologies and encourage others to pursue such sciences.
RUclipsr Robert Murray Smith has an episode that shows how to greatly increase the output of solar cells. One involves amber filters and focusing devices. You should look at the video. It's episode 1664.
That was the best scientific video I've seen in a while. Incredibly detailed and professional. Subscribed!
Thanks, and welcome!
It would be fun to see this combined with overclocking panels with reflectors. How much can you squeeze from a small array??
Not a dedicated reflector but Out here in new mexico i know a guy has a ground mounted pergola type solar setup hoisted a good 20 feet in the air and the entire roof line is angled. He used bifacial panels and then lined the area around the panels with white gravel and white cement under the pergola.
Said he saw a noticable increase in production once he putthe rocks and cement down.
Small ultimate power plant with small servos to keep it in 90... just as a flex .... to show that is possible.....
I’d like to see a few more iterations on this idea.
I’d love to see temps and wattage of a panel by itself. Then another with the back panel where the fans are mounted to see if passively cooling with just fins had any effect.
A modification I’d be interested in seeing would be to use boxed fins with air directed through, and also water directed through fully boxed radiator fins to see if water could carry away more heat than active air cooling. Not sure if a pump could match the efficiency of simple fans.
I may try to get a similar setup to try experimenting. I just got panels installed on my roof and would love to extend their lives and make them more efficient.
This channel is one of the perks of the Internet
Fantastic content! Would love to see more on solar efficiency in future videos. Please make some content on tying it all together with something like heat pumps. This channel is one of the best things on YT.
Currently my panels here in the Northeast are putting out 8kW. I want to add more panels/efficiency for those days when we see no sun. Thanks for the videos, they're very informative.
Very illuminating. People always forget about the heat and the heavy metals. Thanks for sharing.
When my wife and I went to Taos NM in 2017 to spend some time learning about Earthships, I suggested that they do this without fans to try to improve their panels. It is always breezy out there and I figured making and attaching fins to the backs of the panels would help dissipate the heat and boost the panel efficiency/increase the longevity. Glad to know it works... too bad they aren't interested in testing and gathering hard data to prove anything.
Earthships? You mean the tweaker houses made out of garbage?
This takes me back to the video about using reflectors to boost the output from a single solar panel, since one big issue with doing so was that exposing the panel to over twice the amount of sunlight would probably fry it, this seems like it would be a great way to reach the top rated power output even on less than ideal conditions
I saw one panel that had one tiny cell, with huge heat sink and a focusing lens to concentrate sunlight.
The benefit demonstrated in your experiment is overstated. The baseline should have been done without the heatsink and shroud. The high temperature may have been artificially high due to the lack of natural convective current on the back side. You could at least test the junction temperature of an unmodified panel in the same conditions with your second unit to confirm the validity of your test method.
Glad to see you back in action! Please take this as positive feedback… you might want to run your audio through a low pass filter to remove the low frequencies that the wind or moving around is causing. Watching you video on my surround sound system causes my house to shake! Thank you. Keep them coming!
In general the gain could be lowered a little bit, with headphones on it sounds like he's in my head! 😄
Maybe watch his videos through a low pass filter to remove the low frequencies that the wind or moving around is causing.
@@sidthetech_USA haha. I’ll get one just for his channel. ;p
I thought the same.
@@MakersAcres I have specialized audio equipment configurations for each video I watch within my facility that hosts many pre-calibrated rooms with specific environment controlled tech custom tuned for each of these videos... all equipped with a deluxe LazyBoy recliner and haptic suit for maximum enjoyment.
Only the finest.
; )
MTBF would be my primary argument against adding dc/dc voltage regulators, fans and heat sinking. I'd be curious to see the performance uplift of just adding the heatsink without the backplate and fans. Either way, excellent bit of content as always!
It boggles my brain how good the content is on your channel. I'm super happy I ended up finding it!
So are we!
Good to see you back making bangers after what happened!
Banger. Lol. I see what ya did there.
Love this type of detailed testing an explaining. Keep it up. Testing all the things I’ve wanted to test but haven’t been able to because of time and money constraints.
Water heating type of these panels are pretty popular in the Mediterranean. We had one installed about 15 years ago. The water was so warm that I'd had to introduce cold water at the combination tap.
As always a well made video with proper physiks. Living in an area with moderate temperaturs I'm currently leaning more towards just adding more panels instead of optimizing them for peak power. I have issues with not having enough power in the winter and low lights (panels are cold there anyway). As I can't store the power long enough to be usefull. In the summer the panels produce more than enough power already. And the roof is not full yet ;). Also moving parts are not what I like to have (but that is just me). I clearly see areas with limited space and enough storage to benefit exactly from what you tried there.
Word class methodology. Showing the meters clearly and continuously is virtually unseen on youtube. Thanks! love how realistic and well thought the analysis is.
I think you can make it even more efficient.. You could attach a small electric water vapor thingy to the back, that blows out a little bit of water every so often, at the back of the solar panel, covering the inside of the back in a thin layer of water.. this, together with the fans, would cool off the back of the panel even more, due to evaporative cooling.. It would literally cost almost no extra electricity to add this to the system.
✔
It is far better to circulate water through pipes attached to the back and get free water heating.
@@rogerphelps9939 depends on what you can use the “hot” water for. I have a two story house with a gas water heater in the basement, and would be surprised if I could bring that heat from the roof to the basement with a net gain. Not saying it isn’t possible, but it seems unlikely for a trickle of warm water.
@@rogerphelps9939 While i agree that circulating water would cool down the panel to a greater extend then water sprayed on the back with air blowing over it, this would most likely take too much power to run.. for this system to work, you would need to use alot of electricity to pump the water around.. you might get around this problem, by having some sort of rain water catcher, that holds onto the water, at a higher elevation then the solar panels, and then slowly releases it down some thin tubing over the course of a hot sunny day.. but if you are circulating the water, you will have to use a pump, and pumping water would most likely cost more electricity then what is gained.. not only that, but the water that is circulating, has to be cooled off somewhere, so you would need something like a radiator with a big enough surface area, to cool the water down, else the water would just heat up slowly.. But if you misted the back of the solar panel with some kind of electric spray bottle or something like that, it would cost almost no extra electricity, and with the fans blowing over the water, it would cause the water to evaporate.. when water evaporates from a surface, the surface cools down a bit.. this is how "swamp coolers" work.. thats why you feel cold air, if you sit infront of a swamp coolers output while your room is hot.. the problem with swamp coolers tho, is that swamp coolers not only cools the air a bit, but they also raise the air humidity quite a bit.. so even if you manage to cool down your room by a few degrees, it wont really help much, since the humidity is higher.. with higher humidity, the "warm feeling" in the room intensifies.. just like when someone puts water on the hot thingy in a sauna.. but this is no problem outside where a solar panel might be located.. outside you just gain the cooling effect on the panel
I really appreciate your videos. You actually build and test the things I just sit around and think about forever stuck in a state of analysis paralysis. I was surprized yesterday how warm the panels are when the ambient air near freezing and the aluminum frame of the panel (black, shoulda been light) is comfortably warm. I just got them this fall and really wonder what the temp of that frame is going to be in August? The cats sure seem to like to hang out behind them on a chilly morning.
One thing not mentioned is the reasonably expected lifespan of the fan motors. If you installed 100 of those fans, how many of them would not have seized bearings in 10 years? I wonder if electrostatically charging the air with HV, moving air with no moving parts might be a better option? Dyson fan for clues.
I think closed circuit liquid cooling is where it is at, much easier to utilize that collected heat elsewhere which could be considerable on many sq ft of panels. After watching your solar water heater/PV drag race, I'm sure you are readily aware of the heat potential, well over half the radiant energy caught by that PV panel becomes heat at the panel that must be convected or radiated or in the case of liquid cooling, conducted away. You would have a hybrid solar water heater/PV that makes flowing electrons too! Maybe use a sheet of coroplast(styrene) or polycarbonate greenhouse panel to make a heat exchanger that can be glued on the back face of the panel, would be pretty easy to fashion multiple circuits with and exacto and a soldering iron if that seemed beneficial. If you used silane for glue it could be easily reversible to not mess up your panel if it doesnt work out. Coroplast can be purchased with a decent layer of thermal insulation sandwiched on, and greenhouse panels can be purchased that have 2 or 3 layers deep for insulation purposes. Thanks for doing and sharing what you learned.
I had a similar thought about the fans needing to be replaced multiple times through the panel lifetime. There's also the added cost of the heat fins and back panels.
Also I don't believe the Dyson fans are electrostatic. They have a fan in the base and the airflow is directed up to the manifold in the top section. But I like the idea of cooling with no moving parts.
@@CheddarKungPao Thanks for the correction on Dyson fan.
I have computer fans stacked about an arm's length from early 00 and the fans still work well. Most of these have ran through at least 1 if not 2 or 3 versions of Windows. The fans outlasted the system being relevant in most scenarios. I am not positive to the max life of solar cells but you could not buy any rated past 10yrs before recently if that has even changed. The clear coating on the cells will have to be redone if they are even still functionally efficient enough to run as a modern system after 10yrs of improvements to material research. Plan the purchase I guess for a summary and look at the lifespans on your investments in cells.
@@rallyfeind You are way off on solar cells. Panels last basically forever and 25 year warranties guaranteeing 90%+ performance after 25 years are industry standard. But most panels are still working just fine after 30+ years. They have glass covering them, not clear coat.
Sure sometimes electric fans last forever, electric motors are very simple and tend to have very little wear in operation. But you're missing the point that these would be outside and exposed to the elements and running constantly 24/7 in hot weather. Then you add in that there will need to be 3 per panel, and with my solar array that would be 84 fans. I'd be replacing fans pretty regularly instead of just having a maintenance free array. I think the extra money and effort would be better spent on a few additional panels. And this simple calculation is why nobody really bothers with active cooling of solar arrays.
@@CheddarKungPao Neat. You spent way to much effort to explain something has changed. You didn't tell me how or why like you know only that you are aware of numbers as they stand today. Thank you for the update to the standards without any insights beyond saying that I was outdated in info. Good talk though. Oh can you send me a link for hail-proof glass they are using because that is something I would love to get since I live in a tornado heavy area and hail is inevitable not just possible.
Love to see the test of air cooling and your flat concentrators. Thanks for the videos. ❤
You could improve things significantly with a fluorescent polyethylene film over the panel to absorb UV and re-radiate the energy at visible light spectra the panel can use.
This will also stop IR and UV frequencies heating the panel.
And double the surface area available for your air cooling, as you can pass air through the cavity on the front as well as behind the panels.
I must admit - when he was talking about spectra I thought we were about to hear about a filter/reflective coating he was experimenting with. Active cooling and major modifications sounds more expensive than just adding another panel to the array for the extra power.
How much attenuation of the light at critical wavelengths occur, when using such a polythene sheet, wavelengths which are used by the panel to create electricity?
@@deang5622 you may lose 5%. But Infrared is blocked very effectively, and the fluorescence can boost output by over 30%.
Robert Murray Smith on RUclips TnT demonstrated it with a green leaf smoothy. Blending up some green leaves, and making a chlorophyll dye. Chlorophyll is fluorescent.
Even soaking a piece of paper in the dye and putting it over the panel improved it's output significantly.
Though chlorophyll is degraded by UV, so not the best choice.
A really interesting episode. My only problem with the power differential was that the baseline was the modified panel with a mostly enclosed back. Are the aluminium fins compensating for this passive airflow that would otherwise keep the panels cool?
That is a great point, he needed to do the baseline with an open panel, not the one set up for passive cooling
I wonder what the baseline of the open back panel is?
Agreed
Agree
Love this- absolutely bs-free experimental set-up- both as a learning exercise and more importantly a platform for playing around yourself. These types of things ALWAYS seem to leave out critical details (as you alluded to with the Rice paper on graphene) that are obvious [only] when you actually get 'burned'.
Great video! Very well explained and interesting topic, a small correction in the manufacturing. The vast majority of solar cells today are made by starting with a P-type silicon wafer, and then doping that from the outside by hot gas diffusion, greating the P-N junction. The front and back electrical contacts are usually applied as a solder paste, and then baked in an oven. On the back, an aluminium paste is also applied to create a very heavily P-doped layer, which help reduce carrier recombination, and increases the efficiency. It is usually only 2nd and 3rd gen solar cells that start with a substrate, and then deposit the thinner layers on top, as this is a much more expensive process.
Where's the solar powered factory that makes solar panels? Where's the research paper?
I would love for there to be a solar powered solar cell manufacturer, but as far as I know there isn't any of those around. Producing solar cells is a huge multistep process, usually different companies specialize in different areas. Which research paper are you looking for?
Looking for attention...
Love all the engineering and scientific principles demonstrated in your videos. Very accessible to young people.
I have learned something watching this channel since the beginning, whatever comes out of this man's mouth you can take it to the bank.i love learning and I appreciate this channel and all that you share with us.
I appreciate that
Great video and channel!
I'd be curious to add into the wear and tear of fans, replacements etc into the total life cycle cost. Depending on the setup storm's may not make having small computer fans very beneficial. Still, if a company looks closely at this like the one example you gave I'm sure they can find better fan designs that are more storm resistant instead of off the shelf computer fans.
Any chance you could show a better picture of how you attached the heat sinks to the back of the panel? Usually there is a vinyl cover on the back of the panel, I am guessing you removed that and put the heat sinks right up against the panel? Any thoughts on keeping moisture out? Also have any thoughts on how to actively cool bi-facial panels? Very cool method of cooling the panels.
Oof! active cooling on a bi-facial would be a PITA since you don't want to block the reflected light from hitting the backside of the panel. Maybe using the water trickle method on the top side as he mentioned and simply having a set of fans blowing across the back of the panel.
@@michiganengineer8621 the trickle method would probably be the best bet. Could possibly use a clear channel and force air through that. Could allow for light to go through and channel air. As far as removing the vinyl backing, I wonder what effect that would have for allowing moisture to more easily access the back of the panel. Perhaps if you sandwiched the entire back panel with thermal paste that could prevent moisture intrusion?
@@Runnerb03that’s what I’m asking myself: bifacial panels or actively cooled classic ones?
@@Runnerb03 For standard panels I'm not sure you'd need to reseal the back, if you did maybe a thin layer of epoxy resin or a conformal coating after the heatsinks have been bonded to the panel. With bi-facial panels I'm pretty sure the backside is already sealed as well as the top.
What about a misting system that evaporates water to shed heat?
Firstly. ALWAYS top notch content. No one does it better. I had 3 ideas after watching this. 1) why not use Thermo Electric Cells adhered to the right angle heat syncs? Heat on one side cooler on the other... maybe enough to run the fans. 2) If a water sync like a lake is not available... consider using the trick of digging down 4-6 feet and burying pipe. Get some precooled air. 3) the approach using the buried pipe can be done using convection heating to move the air without power depending on where is installed.
The thermoelectric generators are very inefficient and will lower the heat removal from the PV panels. The net result is an overall decrease in system efficiency.
There is another cost consideration. How much cost is the cooling system adding overall? Because if I just want 5% more power I could add 5% more panels (assuming there is available space). As much as I appreciate the efficiency and potential life extension of your system, I generally favour the KISS principle. Fewer moving parts is almost always a good idea, especially on an installation with an expected lifespan of 20 years or more. Finally, to make the most of your system you would probably need to add a temperature monitoring system for each panel so that you can identify any problems with the fans and know when to service them. Maybe there is a better way to use passive cooling to keep the system simpler and without moving parts? Could be the ideal compromise. Enjoyed the video, btw!
That's legitimately a nonargument. The cost of a couple fans and some aluminium sheets is nearly nothing compared to the panels and installation. You're also COMPLETELY ignoring the environmental effects of not having to produce even more garbage. A good quality fan can last several decades, the same as a solar panel.
@@Gabu_ You are talking about the environmental effects of "producing more garbage" yet you are suggesting to add a ton of fans, aluminium fins, fan controllers and power supplies, other mounting hardware, etc. You are contradicting yourself.
@@ABC-rh7zc I'm not contradicting myself, you're just clearly completely unqualified to comment about this topic. Recycling or reusing aluminium is easy and cheap. Fans are mostly made of empty space, cheap and easy to discard properly. Solar panels use a shit ton of energy to produce and contain heavy metals, toxic pollutants. Which do you think makes more sense to preserve for as long as possible?
@@Gabu_ you're funny
I had similar issues. One thing that is kind of ignored, which is understandable, not everyone lives in a hot country. The roof surface temperature will be 50°c to 80°c in summer. DC fans generally don’t work well at such high temperatures in a 24/7 environment that wouldn’t require looking after. DC fans are cheap, but if they have to be constantly replaced every 1-2 years, the amount of efficiency gains become a headache. We have flat roof over here, but other countries use slanted roof structure. Servicing, repairing will be immensely troublesome. Plus we get dust storms, dc wire connections will break over time. Had the heat sink worked, that would have been great. Using cold water is an option, but our water tank is usually on the roof, that is already hot. Folks who have underground water tanks will have to live with hot water coming out of the cold tap. Usual panel size is about 3’ x 6’~7’. Those metal sheets may stop working as effective heat sinks. Especially during winters. We have to remember, best testing conditions are done around 22°c with a light cool breeze. If the air temperature is 10°c and panels are warmed up to 18°c because of the sun. This active cooling will cool the panels down and make them more inefficient.
USA is quite backwards in solar technology, bifacial panels solve this issue significantly. Having a white heat sink coated roof works out really well well. Still not sure if worth the investment to go this route. Sorry for the message appearing after a year 😁
I remember nighthawk in light showed a really efficient way to always center the solar panel with 4 slights smaller ones at each of the edges connected to motors. It would seem weird but if you can get small enough panels it could work really well.
The ones at the edges are not really solar panels, they're photoresistive cells that change resistance depending on light. A full tracking system like that is not practical for reliability and maintenance cost reasons. It would also be easier to just use the internet to look up the position of the sun based on location, instead of actively tracking it
@@signalworks I drive past a large scale commercial solar farm occasionally for work, and I noticed the rows of panels were all facing northeast in the morning. Weird direction for central IL, and I assumed maybe they were working on them and somehow had flipped the panels to 'shut them off' so to speak. Later that day (late afternoon) driving past them they were flipped to the southwest and you could see the mechanism that flips entire rows as a whole. Point is some commercial operations are active tracking at least in a single axis so it must be economical on some scale.
This absolutely explains my recent frustration 😤
I have a 1800watts panel array and I have noticed drastic drop in watt output within a year, it is currently given me 400watts at peak value as opposed to 900+watts when it was first installed. I have called the technicians many times to come and test why and explain, they all have no idea why.
But this video gives me an understanding why. Thank you, subscribing...
That sounds like a big drop for one year, even allowing for the temperature effect.
You might check whether there is any shadowing of ANY part of the array. The combined output can be significantly decreased by a weak panel. You might also ask if they checked the output of each panel. The same effect can be caused by a bad panel. In one year, you might still be under a warranty.
Thank you for further clarity. The difference is really much for 1 year. I believe a bad panel is also causing this. I will request for a thorough test of each panel and have any bad one replaced. Thank you
An interesting test that comes with some design flaws that could greatly improve the system, and a series of variables that compound my interest.
1) Fan alignment. You have top mounted intake fans, which is generally a bad location since hot air rises and you fight the natural convection. The panels should be flipped upside down. You also aim the fans so they blow at a nearby surface (the back of the panel), rather than in the direction of desired flow, thereby decreasing CFM due to the pressure losses. Bottom mount the fans, perpendicular to the panel with ducted shrouds to focus the air down into the heatsink channels.
2) Convection has a worse heat exchange than convection. While you state that it doesn't make sense for your setup, I imagine economics of scale against a say 8x3 panel array would improve the numbers on running a pump and radiator.
3) Useful work. Most buildings, be it commercial, industrial, or residential, require how water. Pumping 40° coolant through a heat exchanger in a modified heat-pump style home water heater reduces the workload for a radiator, and re-coops lost power to running the water heater.
4) Temperature delta. While 3W vs 10W to run a few fans is a better solution than 30W vs 10W, lower latitude areas also have worse temperature deltas than NE: Dropping the panel to 30°C isn't a realistic option when outside ambient is already 48°C. A heat pump is a far more efficient for moving heat than ambient convection in high temperature areas, regardless of variables other than scale.
Definitely interesting any efficiency boost to solar without massively increasing cost seems worth it. I would be curious to see the temp difference with the back panel with fans removed rather than just off.
The fans alone will massively increase cost. The simple fact is solar panels are about 1$ per watt these days, and it's going to be impossible to find a high duty cycle fan, that can survive high temps, outside, that will increase efficiency by 1 watt for each dollar spend on the fan. Then consider those fans absolutely will need maintenance, and it's all the sudden not a good idea.
This is cool, but need more data! Strait on with the 68% sun, 3 watts in gave 5 out. But do the fans still help produce more then they use at oblique angles? If you can either test different angles to find the tipping point where the fans stop helping (less then 3watt boost) - or do a full day test facing south at your ideal angle upward (probably 35ish) to get the average for us who don't have panel movers. Would really help give us the full picture.
Also how about a liquid to liquid heat exchanger; setup with antifreeze on the roof side and preheat cold water into hot water heater on the other side. - Cool your panels and preheat water at the same time?
The main issue I see here is that the cost to add the fans and metal to the panel. Sure you gain 2 watts of power but how long would it take to recoup the cost of the additional materials. The second part would be that those fans will most likely go fail somewhere between 5-10 years so the cost of replacing the fans needs to be factored as well.
True, but fans are light, easy and can be modular. Don't forget the benefit of increased panel longevity and operation in very hot climates.
I really enjoy these energy videos. I've been way ahead of you on this so far. If you store the extracted heat in an underground insulated tank/pool, you're offsetting your home heating costs in the winter, while chilling your fluid for panel cooling in the summer. You can also run a closed loop ethylene glycol loop into an aquifer for a few hundred dollars and only run it's pump when ambient temps are over 30-35F. It takes very little energy to move fluid in a loop.
But have you done it?
Thank you for excellent explanation for a total newbie. This is so rarely seen this days - technical topics explained with easy to get language without excessive jargon. Thank you for sharing your knowledge and experience!!! Keep on doing!
Always enjoy your practical experiments and analysis, very interested to see net gain in relatively temperate climates, I’ve been thinking about this for some time but hadn’t considered your approach for homemade heatsink which had made the capital cost prohibitive from my perspective. I do think the heat recovery point you made at the end makes the cost benefit case more attractive even for a domestic Instalation if you can divert that heat through and existing air source heat pump and into your hot water (in theory this would increase efficiency/reduce cost of producing hot water). Nice job 👍👍👍
Always solid content and we are getting it from a first rate technical instructor. I believe I have watched all but 2-3 of your presentations. Congrats ~ Allan J
This is truly the best science and education channel on RUclips!!
I've wondered. Can't you collect the heat from the panel and use it to heat your house in the winter time? Perhaps you could also use this heat combined with a heat pump to pump heat into the ground during the summer, then extract that heat in the winter. AKA stabilize the ground as geothermal heat pumps tend to work well when they start, but it takes around 8 years fore the ground to stabilize. At that point the heat pump looses a lot of it's performance.
I imagine the only effective way to heat your house with this would be through a heat pump. The air isn't going to be hot enough to directly pump into your house (if your displacing 20c air with 15c air, it's going to be a loss)
You could duct the air into a air exchange heat pump, but you would need to redirect it based on if your heating, or cooling your house (heating the outside unit is good for when your heating your house, but bad for when your cooling your house).
My guess at the best way to utilize the heat would be pre-warming the water coming into your house for your hot water tank. The only question then is if it's enough flow to keep the panels cool, the useful heat gained may be outweighed by higher panel temperatures.
There are systems that use heat from the sun to collect heat and transfer it in doors, but from what i've heard they are quite expensive. Its usually an array of glass tubes filled with glycol that gets pumped in to dump heat into a water heater. if you are heating a small enough space, have really good insulation and are already taking advantage of passive solar heating in the design of the building you might get away with using only radiant heating to keep the building warm in the winter. SunMaxx solar has some kits if you want to see what they look like.
I've heard they are a pain to maintain though. if the pump fails for example, you can get into a situation where the system gets too hot and will get damaged relatively quickly.
@@Errzman They did some solar hot water heater stuff in this video ruclips.net/video/5g5PW78XMSo/видео.html the vacuum tubes are not great, you can get a much more reliable system for low $.
Great video as always! Would it be possible to filter out the wavelengths that only add to heating on the front surface of the solar panel via reflection?
Yeah definitely, do a quick google on laser goggles, there's definitely ways of targeting specific wavelengths of light.
I think he mentioned that in a video before. I heard it somewhere. My recollection is that the filtering would lower the input too much to be practical.
@@mikebond6328 tbh that makes sense.
Watching these videos is like going to college for free. This guy is gold.
A couple things come to mind.
First, I'd really like to see the unmodified panel's performance rather than measuring the performance of the panel with heat fins attached but blocked by the outer sheet trapping the heat and not allowing convection heat to flow upwards. I'm speculating that there's no heat sink compound between the fins and the outer sheet of aluminum and just trapping heat inside. With my rooftop solar system on a sunny day, there's significant convection warm air flowing upwards between the panels and the roof deck that whisk away the heat.
Second, the longevity of the fans vs the solar panels. How often do they need replacing?
Third, what is the performance look like with the air heat sink attached but the rear panel removed so that it can just dissipate into the open air. I would guess that would be the best of both worlds. More surface area without adding mechanical devices to the mix.
The back of the panel is shiny. Shiny equals low emissivity. It needs to be black if it is looking at grass! There is also room to place a reflective surface behind the array to reflect the sky. The sky is transparent to IR at 8µ to 15µ and acts as a super cool heat dump.
black is more emissive. Learned that from action lab
If the people woult take a IR kitchen thermometer and aim it in a night with no clouds up outside, they would be shocked.
MINUS 50-60 degres Celsius.
First i did not get it ...
(Think this would also make a good short learning video for Tech Ingrediens ?)
Also, flood systems are more effective than you elude to due to evaporation. However they have their own issues, such as mineral deposit build-up over time - especially in areas with hard water.
For some reason I have an urge to visit the Country Kitchen. 🧐
Welcome to morning news shows
I was wondering if you could convection cool the sun panel. Add an insulated chimney on top to create stronger draft.
In fact you could do an entire video of whether is there a limit to that kind of cooling
It all comes down to the cost of the cooling, 5 watts will make $1 of electricity in about 1 year, solar panels last max 30 years
So if you cooling system gains 5 watts, 6 equivalent hours per day, for 30 years, your cooling system cannot cost more than $30 per 100w to just break even
And few people are willing to put money into an investment that doesnt pay back in 5 to 10 years.
And that's if nothing breaks, gets blown down, damaged by contractors, etc.
@@jaycweingardt11 Since you replied toy comment I feel entitled to intrude:
Note it's around 5 watts in the video for a single panel. Still marginally beneficial but from a more level ground.
@@LiviuGelea Or consider the additional wattage gained from cooling and compare the cost of the cooling system (including maintenance over 30 years) against simply adding the equivalent wattage in additional panels without any cooling. Well, I can already tell you the answer... it is far more economic to simply add more panels to the system than it is to try to cool an installation.
@@junkerzn7312 you’re likely right. Plus, complexity adds its own cost in maintenance
I was wondering the same thing. As stated below by others, I'm also not the biggest fan of using fans, because of the added complexity. However, if there were to be a simple, low cost solution that would last the lifetime of the panels that would be striking gold.
In the solar panel installation on our home there are gaps between the panels. I can't help but wonder if it would have been more effective to seal every gap, and only leave the gaps on top of the rows of panels and the bottom. This would create a chimney almost for free. The top panels would be warmer than the bottom panels (so parallel connection would be required), but you would create a higher airflow, basically for free. Especially on less windy days this might actually result in a higher heat dissipation.
I'm not sure though, it's hard to get an intuition if the pro's would outweigh the cons.
Excellent video! Thinking of a solar project in the spring, Lots of helpful data. Very interesting how you "play-out" the various arguments for/against, plus/minus. I'm a Broadcast Engineer and my wife has a degree in English. You were able to hold her attention too!! Many Thanks!
That's great to hear. The value of content that holds interest for a broad audience is obviously higher.
In a previous video you showed a set of DIY wing reflectors that helped increase how many photons the panel gets, I imagine those would have the same effect as being in an area like the southwest of raising panel temps. It would be interesting to see the effect of that active cooled panel with the wing reflectors attached to see how much more of a difference it makes.
True
I would very much like to see that test happen.
I continue to wonder why solar panels aren't designed to have water cooling to preheat hot water for the home as a win win.
They exist, look for PVT panels.
Was thinking exactly the same. Run a pipe system on the back of each panel, connected to a manifold, and have the whole system connected to a water basin.
I saw at least 2 companies that make solar panels with a integrated water loop, you could also do it yourself pretty easily
Thank you sir, very well done. I was inspired by your Peltier cooler two years ago and decided to build our own for our insulated battery enclosure. Both heats and cools based on internal temp. Now I must thank you again, our East-West Facing system called the SA4 acts very much like a greenhouse in summer. Going forward will install a fan on one of the ends of the array to allow fresh air to flow under the panels when ambient temperature rises above 20 degrees C.
This will surely increase gains, and thankfully our Grid Tie Inverters all come with a 120V outlet at source to power the fan.
Keep up the great content, as a solar installer, it's a pleasure seeing these experiments.
Best of luck!
This video sponsored by Country Kitchen 😂
I really enjoy these how-to engineering videos. Just got off my roof checking temperature of panels and found the heat around the black asphalt shingle roof was hotter that the pv solar panel.
The ambient was 65°F, panel had gotten to 105°F by 10am, and black shingles were already over 135°F. Behind the panel the shaded shingle roof was 90°F!
So my roof heating is going to be more of a problem than I expected.
True.
And, that might be the most cost-effective issue to focus on.
I love the channel! This father and son work hard and it's educational. Thank you very much.
Our pleasure!
Thanks so much for the great engineering videos and the detailed explanations. As an engineer myself, I always learn quite a bit from your videos.
A clear scientific demonstration of the value of keeping the solar panel temperature in a safe range.
Thank you🌹.
The refrigerator runs on 100 watts power through the day. A 12 volt 8A panel can supply this power for 6-8 hours a day for twenty years. This greatly exceeds the cost of the panel. So it's a great saving. No power failure. Safe.
I take a break but always click when a video comes up. Your work and production quality are superb.