Nice. I cant wait for your next heater. For the thermal connection from diode to the water you can file a provisional patent as a micro entity at the USPTO for 25% of the normal cost ($64). That filing will give you 12 months to research if you need to proceed with a full filing, As an individual inventor the micro entity status means all patent costs will be charged at 25%.
It works great, I have used the body diodes of mosfets, it works great and you can then actually control the string by switching on the mosfets if you want, thus effectively decreasing and increasing the amount of diodes! Another plus is that the mosfets makes really good thermal contact with the system you want to heat, like a water reservoir for instance. I have used that same heat to generate electricity by using the seebeck effect of a peltier module in addition to heating water or supplying the input to a switch mode voltage regulator for battery charging!
@petrusbosman4264 Great ideas :) can also use those metal power rectifiers, they have a ton of metal. Good for heat sinking. I am thinking a MOSFET could be used to short out some of the diodes and change voltage or power level instantly. Lots of options!
For some solar panels brands (e.g TRINA SOLAR, JINKO SOLAR, ...) , the datasheet contain graphs similar the ones shown in fig 6 of the paper. The two graphs can sometime be merged into a single graph with two vertical axis. Each graph typically contain 4 or 5 curves corresponding to various solar illuminations (e.g. 100%, 80%, ...). As shown in the scientific paper, those graphs can be used to predict the efficiency of a resistor or of a diode chain. They really helped me understand how U, I and P are related on a solar panel.
@cynodont7391 Thanks for sharing the information! that stuff can take awhile to absorb and understand... I must say this type of paper is a real gold mine, so much to learn :D
Please correct me if I'm wrong, but I think the thing so many people are missing and get confused about with your videos is that the point of using diodes is that they tune the output voltage to be as close as possible to the voltage at which the solar panel is designed to work most efficiently. That's all. There's no hand waving, energy out of nowhere BS. It's is NOT magically producing more heat out of a certain volts/amps curve (which is generally far from the optimum for a given panel). What it is doing is letting the solar panel work closer to its engineered peak efficiency for more of the day. I suspect a lot of people who get so upset about this don't really understand the point of MPPT, or that using a string of diodes is a simple, cheap way of approximating MPPT.
@fxm5715 Epic post :) Good points and good explanation. This topic has attracted previously unseen levels of ridicule and negativity because it's outside most peoples "comfort zone". But that's where progress happens! "Progress Has an Open Mind"
Here’s my vision for this: You’re right about the impoverished needing cooling energy. Current option is to cut down trees. A simple high tech way is solar cookers and PV to diode cooker. There will be less demand on trees, allowing trees to fruit and gaining another potential source of nutrients. I love this channel. This channel is being the hero I want to see in this world Even setting aside the Green Is Good value, people with self sufficient values or anti corporate greed value should be loving this channel
@peterxyz3541 I love the vision! Appreciate your support! I have seen where struggling villagers who managed to find some food - but it was left to spoil because they couldn't even get fuel to cook. Imagine a small dirt cheap solar electric cooker and small solar panel, cooking endless meals INDOORS (under shelter, more civilized than outdoor cooking) for years to come! If the cooker breaks, it's a 10 cent piece of nichrome or a a couple of diodes, it is not out of reach :)
This is absolutely fascinating. I was working on a resistor Network and mosfets to "tune" the Load to the Panel.. but you've just blown that out of the water! Thanks! Diodes have been suitably ordered!!
@timbrown9305 Meaning circulating liquid to heat a room? A tank of water with foam around it could store a nice amount of heat! I would like to do that but I am hesitant to have a lot of liquids stored in the workshop. A mixing valve could control how much heat is released from the solar panels vs. stored in the tank, or just run it straight through the system
I'm working on this. I'm going to use solar water heaters and then use a heat pump to increase temperature and store the heat in a phase change material.
Just provide a temperature controller that will switch off when it reaches 100°C then turn back on when it reaches 95°C. The temperature of your cooker will just play along 95-100, enough for the long life of the diode. #my2cents
Having used diodes many times for obtaining desired voltages this of course makes perfect sense. My thoughts went toward tab mounting diodes with either the metal TO220 style case or the similar size ones with insulated backs as these could be quite easily mounted to a flat surface with good thermal contact perhaps using the clamp method often seen in power inverters. Thinking of control I thought of a mosfet at the 0v end of the chain with its gat connected to 0v via an NTC thermistor and then a resistor from the gate to further up the chain, or even to positive with a value so that up to the max temp the gate is kept turned on but, when the aiming temp is approached, the NTC puls the gate towards 0v so turning the mosfet off, this could even be used to make a variable temperature if you wanted to, for instance, keep a pot at a slow cooking temperature. Being solid state there would be no contacts to go all irrelevant on you and low voltage high power MOSfETs and thermistors are really cheap. The MOSFET would of course also be cooled by the pot. With 400W solar panels now much cheaper than their controllers, never mind batteries, this could be viable. While I looked at the graphs I’m not sure they would hold true for an MPPT controlled battery system as their the actual power is tracked rather than the PWM controllers where the battery voltage of say 12v under load limits the output of a panel with an 18Vmp to 2/3 of its potential power. An MPPT would hold the panel at Vmp and also vary it as the panel temperature changed to keep it at its sweet spot. Of course you get inefficiencies in conversion but the main issue is the cost. Another use just came to mind so you could use the cheap 30v panels with cheap PWM controllers charging batteries but also having them connected to a diode heater with its voltage set at the panel’s Vmp, that way you get battery charging that swaps gradually to heating as the batteries start absorbing and the diodes harvest the power from the PWM peaks which increase in length as the battery charge current decreases. These days 400W 60c panels are very similar in price to 100w 36 cell ones.
Have just ordered up some 135 C (off) / 110 C (reset) thermal switches for my project. Since my diodes max running temp is 150 C, this should let me boil water with no problems or cook a roast to rare/ medium rare just how i like it. Still wondering if I can work with sand at 135 C as a viable night heater.
0:16 «It is better to err on the side of using too few diodes than too many». Both are probably true. If you put many diodes in the chain then the voltage could become too high and the current & power will decrease sharply (see figure 6). However, a simple way to reduce the current and so the power dissipated by each diode is to use multiple identical diode chains in parallel. That seems obvious to me but I do not remember seeing that idea in your videos or in paper (which I still have to read carefully). The system will cost more but the risk of overheating will be reduced. significantly.
@cynodont7391 Good points! I'll try to remember to include this in the next video. Operating Temperature of the heater plays a role too, very important! I have always heard don't use diodes in parallel, but that isn't going to stop us :D PS if you are interested... power bridge rectifiers are fantastic for regulated solar electric heating. They are pretty tough with a metal case. I have been using 50 amp ones to heat my workshop, and of course they are also in parallel!
I was looking into that today after I saw this video. Apparently due to tiny tolerances in each diode the diodes don't share the current evenly when in parallel so one diode tends to consume more power and get hotter than the other which leads to failure of the hotter diode. If the diode is cooled and kept below the failure temperature then that should not be an issue. The researchers in the paper stated they could pump 40A through the diodes as long as they were cooled and they are only rated at 3A.
@@cgmarch2359 Nice video, I guess i need to stop reading and start trying stuff. The theory people seem to have it all wrong. Could you add the details of the test to the video? Volts, amps, diode type etc. & why you were trying it, was it to test for heat generation or just to see if it works?
@peterxyz3541 Right on :) wish I could show you... on my workbench is one diode heater prototype, and a bigger one in testing, hooked to 2 extra 200w panels outside. It's not quite winter here, early fall... definitely getting ready :D
My battery disconnected from my solar charge controller and cooked the diodes on my solar panels. I assume they were there to meter the voltage but the panels are still working fine.the charge controller caught fire.
Could I mount these diodes to 1/8 inch alum, sheet to make radiant heaters for my garage? ( or radiant/ convective ) I have 2,4 by 8 solar air heaters, but these are hard to mount and need fans to move the air thru them, I would need 3 times the area of solar panels, but they could mount anywhere. , Or just be put up for seasonal use. The alum radiant heaters would be in a 40 to 80 deg. F enviroment. Something with no fans or switches sure sounds nice. These seasonal panels could mount almost vertical and would provid emergency power if needed.
for thermal connection in diy immersion elements(tubes for example) you could use hexagonal boron nitride powder (NOT the cubic form which is extremely hard and used in grinding and cutting applications) Hexagonal boron nitride is a white powder which is electrically insulating, thermally stable, non toxic and most important of all its thermal conductivity rivals that of copper. might sound like an exotic material but it can be had from aliexpress for like 20-25$ per 500g . a metal tube closed at one end filled with a diode string and the powder and then compacted to eliminate air pockets and ensure good thermal contact. Pretty similar in principle to how resistive immersion heaters are built.
@greygleam Hi, cutting edge stuff... thanks for sharing! I was looking to use magnesium oxide powder and a several other (must be non toxic) substances, but you're right on the mark.. just found some hexagonal boron nitride in small jars for sale! Thank you :D
Im not sure if I missed something here run the solar pannel through a series of diodes and use the emmiting heat. The voltage drops after passing througg the diode by at least .4 volt but often more ?
@ponemark Sounds right! I'd also add, match the voltage of the diode string to the vMP of the solar panel (like MPPT does). The voltage can vary, but it's easy to fix by adding or removing diodes
@richardsandwell2285 Great idea - I am building a submersion element for a water tank. Trying some smaller diodes this time. With fish I imagine it would be important to control the temperature (thermostat control) very interesting to use solar for this
@peterwright4656 In short, Nichrome resistance cannot regulate the solar panel to the most efficient voltage (that's what MPPT does) but oddly' enough a string of diodes behaves almost exactly the same as MPPT... so they can extract more heat under widely varying conditions
What about zenner diodes. It is possible to find powerful ones, which gives smaller amount of them, comparing to diodes. You can easily get them for any viltages. Even 48V for new solar panels or make series of them 4x12V to get smaller voltage or destribute power among them.
This is really good to see and very cool. It looks kinda dangerous for a DIY newbie like myself. However, I would like to know if there are similar options for an inverter system.
@ekeretteekpo3004 Hi! I'm glad you liked this paper... I never thought diodes should be used for heat... but new ideas take some getting used to :) Regarding your question on inverters: we'd only want to connect diode strings straight to a solar panel - reason is, solar panels limit current and need regulation at a specific voltage. Batteries and inverters don't really limit current and would burn diodes up, BUT you can just use "normal resistive heaters" for those setups. If you want to make pure heat cheap and direct from solar panels (no charge controller, no inverter, no battery to buy) diodes can really shine. This whole topic is honestly pretty confusing but I hope my reply is at least a little helpful :D any questions feel free to ask! -Dave
@@solarpoweredge thank you for the quick response. I already have a solar system setup (a small one - 1KW) and, seeing how this is, was thinking of something that could work for it.
Hi. How do you regulate the temperature from getting to high and causing damage in your diode chain? Just a thermostat? Say someone placed a diode chain in a sand battery connected to a couple solar panels.
IMAGINE…. (I work at a bakery, conveyor oven and all) …..using diode to bake or just to pre-heat the volume in oven before burning natural gas Yes, paten it!
@peterxyz3541 Good thinking :D I always wondered, what about those steel mills and foundries requiring massive amounts of heat? Build a massive solar farm next door and short circuit it through the furnace. PV to load ! Cut your electric bills! Any remaining heat can come from the grid or gas, but only as needed
@L0615T1C Sure, it's worth trying! They cost more I think. Keep in mind, there are metal tabbed power diodes. I am using 50a bridge rectifiers to heat my workshop, they seem fairly tough (metal case) but slightly more expensive than axial components of course
@Voidsworn Hi, one could say they are 100% efficient just like nichrome. Diode strings are only recommended for direct-connect solar electric operation, because solar panels need to stay at max power voltage (MPPT). Resistance wire cannot do that on its own. If you're running off 240v AC, standard resistance heat is still the way to go... hope that helps !
@@solarpoweredge when you say resistance heat, what do you mean? Can you recommend devices based on that? Are there cheaper alternatives that are also as efficient?
@ekeretteekpo3004 Hi, the most common type of electric heating element is literally just an electric resistor. It may be a piece of nichrome wire, a metal bar, ceramic plates, but no matter what it's just a resistor. *A resistor has Impedance (aka resistance) and it resists the flow of current, causing it to get very hot at a certain voltage. All electrical heating elements are technically 100% efficient, meaning you put in 100 watts, you get 100 watts of heat. *But when using only a solar panel to make heat, resistance heating elements don't work too well, and cannot keep the solar panel at the proper voltage to maximize heat. They lose a lot of heat as a result, it's never captured. *It just so happens a string of diodes can regulate the proper voltage of a solar panel, and they get hot, so they beat standard resistance heaters for direct-connected solar electric heating. *Diodes are not resistors, and may seem to behave a bit strange. They have no significant resistance to current. They regulate themselves, unlike a resistor element. *I do not know of any cheaper alternative besides diodes for direct solar electric heat. An MPPT converter will behave similarly, but it cost a lot of money versus cheap diodes. Here's an example of a resistor cooking food my mini PV DC oven - it's direct solar driven but still works. It has insulation to improve efficiency. ruclips.net/video/qj-sa0bZPCw/видео.html Here's a DIY mini 12 volt oven build using resistance heating, doesn't use much power but cooks food easily: ruclips.net/video/z0dKupye594/видео.html Another resistance based oven that runs on 18v power tool batteries: ruclips.net/video/SLiwNnHPlI0/видео.html Simply put, with battery power, we can use a resistor for heat - it's 100% efficient. With solar power, we can use a resistor (doesn't work as well) OR diodes (works better if properly configured). I hope this is helpful. My aim is to share knowledge and information, even if it's not quite mainstream - diode strings are still very obscure and unknown.
@ekeretteekpo3004 No problem! yes that term is technically correct. (because they use a resistance heating element to produce the heat from voltage and cook the food)
What about using direct solar to power 120v infrared light bulbs as an ultra simple heat source? I have (4)120w 20v panels I could arrange in series/parallel to produce 480w at 60v dc to power an 300w infrared bulb.
@solarpoweredge I am going to explore this as well. Lowes carries a dimmable ceramic heater bulb. Easy Bake Ovens use a 100w lightbulb to bake their cakes.
@803mastiff9 Great... I ordered a set of ordinary infrared bulbs last night, it just so happens I will have a metal box to put them in too. I am interested to see what they could do
Ceramic heating elements tend to increase their resistance as the temperature increases, which could be a good thing. And there are 12 volt elements available too.
@jima3252 Right on... that also helps increase safety... those ceramic (PTC) heaters are pretty awesome! I used some to heat the back room with 2 and later 4 100w solar panels. Was really surprised how much difference the setup made... 2 thin wires to get all that heat inside... Found some of the videos showing PTCs ruclips.net/video/UxgINFgqUoI/видео.html ruclips.net/video/wK3_lRSntRc/видео.html
Nice. I cant wait for your next heater. For the thermal connection from diode to the water you can file a provisional patent as a micro entity at the USPTO for 25% of the normal cost ($64). That filing will give you 12 months to research if you need to proceed with a full filing, As an individual inventor the micro entity status means all patent costs will be charged at 25%.
@mikefiatx19 Huge thanks for sharing that info! I was totally unaware!
It works great, I have used the body diodes of mosfets, it works great and you can then actually control the string by switching on the mosfets if you want, thus effectively decreasing and increasing the amount of diodes! Another plus is that the mosfets makes really good thermal contact with the system you want to heat, like a water reservoir for instance.
I have used that same heat to generate electricity by using the seebeck effect of a peltier module in addition to heating water or supplying the input to a switch mode voltage regulator for battery charging!
@petrusbosman4264 Great ideas :) can also use those metal power rectifiers, they have a ton of metal. Good for heat sinking. I am thinking a MOSFET could be used to short out some of the diodes and change voltage or power level instantly. Lots of options!
What a great idea.
For some solar panels brands (e.g TRINA SOLAR, JINKO SOLAR, ...) , the datasheet contain graphs similar the ones shown in fig 6 of the paper. The two graphs can sometime be merged into a single graph with two vertical axis. Each graph typically contain 4 or 5 curves corresponding to various solar illuminations (e.g. 100%, 80%, ...). As shown in the scientific paper, those graphs can be used to predict the efficiency of a resistor or of a diode chain. They really helped me understand how U, I and P are related on a solar panel.
@cynodont7391 Thanks for sharing the information! that stuff can take awhile to absorb and understand... I must say this type of paper is a real gold mine, so much to learn :D
very interesting and awesome info
@lorenwright3202 :D 👍
Please correct me if I'm wrong, but I think the thing so many people are missing and get confused about with your videos is that the point of using diodes is that they tune the output voltage to be as close as possible to the voltage at which the solar panel is designed to work most efficiently. That's all. There's no hand waving, energy out of nowhere BS. It's is NOT magically producing more heat out of a certain volts/amps curve (which is generally far from the optimum for a given panel). What it is doing is letting the solar panel work closer to its engineered peak efficiency for more of the day. I suspect a lot of people who get so upset about this don't really understand the point of MPPT, or that using a string of diodes is a simple, cheap way of approximating MPPT.
@fxm5715 Epic post :) Good points and good explanation. This topic has attracted previously unseen levels of ridicule and negativity because it's outside most peoples "comfort zone". But that's where progress happens! "Progress Has an Open Mind"
Here’s my vision for this:
You’re right about the impoverished needing cooling energy.
Current option is to cut down trees.
A simple high tech way is solar cookers and PV to diode cooker. There will be less demand on trees, allowing trees to fruit and gaining another potential source of nutrients.
I love this channel. This channel is being the hero I want to see in this world
Even setting aside the Green Is Good value, people with self sufficient values or anti corporate greed value should be loving this channel
@peterxyz3541 I love the vision! Appreciate your support! I have seen where struggling villagers who managed to find some food - but it was left to spoil because they couldn't even get fuel to cook. Imagine a small dirt cheap solar electric cooker and small solar panel, cooking endless meals INDOORS (under shelter, more civilized than outdoor cooking) for years to come! If the cooker breaks, it's a 10 cent piece of nichrome or a a couple of diodes, it is not out of reach :)
This is absolutely fascinating. I was working on a resistor Network and mosfets to "tune" the Load to the Panel.. but you've just blown that out of the water! Thanks! Diodes have been suitably ordered!!
@rockafella8977 Nice! Another one for the diode team!
This helps in the desire I have for hydronic radiant heat. I want to store heat as well but that is very high temp.
@timbrown9305 Meaning circulating liquid to heat a room? A tank of water with foam around it could store a nice amount of heat! I would like to do that but I am hesitant to have a lot of liquids stored in the workshop. A mixing valve could control how much heat is released from the solar panels vs. stored in the tank, or just run it straight through the system
I'm working on this. I'm going to use solar water heaters and then use a heat pump to increase temperature and store the heat in a phase change material.
Just provide a temperature controller that will switch off when it reaches 100°C then turn back on when it reaches 95°C. The temperature of your cooker will just play along 95-100, enough for the long life of the diode.
#my2cents
@abuxxx3607 Good thinking... I bought some of those small 100C appliance thermostats, not sure how durable they will be but worth a try
Who knew diodes could produce heat? It seems to produce a lot of possibilities. Thanks for the update!
@jima3252 Welcome :D they are probably the most unusual heating element I have ever heard of!
Having used diodes many times for obtaining desired voltages this of course makes perfect sense. My thoughts went toward tab mounting diodes with either the metal TO220 style case or the similar size ones with insulated backs as these could be quite easily mounted to a flat surface with good thermal contact perhaps using the clamp method often seen in power inverters. Thinking of control I thought of a mosfet at the 0v end of the chain with its gat connected to 0v via an NTC thermistor and then a resistor from the gate to further up the chain, or even to positive with a value so that up to the max temp the gate is kept turned on but, when the aiming temp is approached, the NTC puls the gate towards 0v so turning the mosfet off, this could even be used to make a variable temperature if you wanted to, for instance, keep a pot at a slow cooking temperature. Being solid state there would be no contacts to go all irrelevant on you and low voltage high power MOSfETs and thermistors are really cheap. The MOSFET would of course also be cooled by the pot. With 400W solar panels now much cheaper than their controllers, never mind batteries, this could be viable. While I looked at the graphs I’m not sure they would hold true for an MPPT controlled battery system as their the actual power is tracked rather than the PWM controllers where the battery voltage of say 12v under load limits the output of a panel with an 18Vmp to 2/3 of its potential power. An MPPT would hold the panel at Vmp and also vary it as the panel temperature changed to keep it at its sweet spot. Of course you get inefficiencies in conversion but the main issue is the cost. Another use just came to mind so you could use the cheap 30v panels with cheap PWM controllers charging batteries but also having them connected to a diode heater with its voltage set at the panel’s Vmp, that way you get battery charging that swaps gradually to heating as the batteries start absorbing and the diodes harvest the power from the PWM peaks which increase in length as the battery charge current decreases. These days 400W 60c panels are very similar in price to 100w 36 cell ones.
@philbrooke-little7082 Those TO style ones work nicely, fyi power rectifiers seem very promising too. In fact they're currently heating my shop :D
Have just ordered up some 135 C (off) / 110 C (reset) thermal switches for my project. Since my diodes max running temp is 150 C, this should let me boil water with no problems or cook a roast to rare/ medium rare just how i like it. Still wondering if I can work with sand at 135 C as a viable night heater.
@ianball3972 I have bought some appliance thermostats to test, not sure if they can take DC long term but we'll see...
0:16 «It is better to err on the side of using too few diodes than too many». Both are probably true. If you put many diodes in the chain then the voltage could become too high and the current & power will decrease sharply (see figure 6). However, a simple way to reduce the current and so the power dissipated by each diode is to use multiple identical diode chains in parallel. That seems obvious to me but I do not remember seeing that idea in your videos or in paper (which I still have to read carefully). The system will cost more but the risk of overheating will be reduced. significantly.
@cynodont7391 Good points! I'll try to remember to include this in the next video. Operating Temperature of the heater plays a role too, very important! I have always heard don't use diodes in parallel, but that isn't going to stop us :D
PS if you are interested... power bridge rectifiers are fantastic for regulated solar electric heating. They are pretty tough with a metal case. I have been using 50 amp ones to heat my workshop, and of course they are also in parallel!
I was looking into that today after I saw this video. Apparently due to tiny tolerances in each diode the diodes don't share the current evenly when in parallel so one diode tends to consume more power and get hotter than the other which leads to failure of the hotter diode. If the diode is cooled and kept below the failure temperature then that should not be an issue. The researchers in the paper stated they could pump 40A through the diodes as long as they were cooled and they are only rated at 3A.
I posted a video showing 2p2s diodes ...they warm at same rate so for sure you can parallel to spread current /heat
@cgmarch2359 Watched it.. awesome test!
@@cgmarch2359 Nice video, I guess i need to stop reading and start trying stuff. The theory people seem to have it all wrong. Could you add the details of the test to the video? Volts, amps, diode type etc. & why you were trying it, was it to test for heat generation or just to see if it works?
Also, I’m planning to build a string of diodes for supplementing my winter heating. If I can raise the ambient by 10-15f, it’s less heating cost.
@peterxyz3541 Right on :) wish I could show you... on my workbench is one diode heater prototype, and a bigger one in testing, hooked to 2 extra 200w panels outside. It's not quite winter here, early fall... definitely getting ready :D
Diode sand battery to store up thermal mass energy might be an idea,but the 120* degree optimum operating temperature might be a limiting factor.
My battery disconnected from my solar charge controller and cooked the diodes on my solar panels. I assume they were there to meter the voltage but the panels are still working fine.the charge controller caught fire.
@jestercrusher7743 Wow that's not fun! I'm glad at least the panels are still working
Could I mount these diodes to 1/8 inch alum, sheet to make radiant heaters for my garage? ( or radiant/ convective ) I have 2,4 by 8 solar air heaters, but these are hard to mount and need fans to move the air thru them, I would need 3 times the area of solar panels, but they could mount anywhere. , Or just be put up for seasonal use. The alum radiant heaters would be in a 40 to 80 deg. F enviroment. Something with no fans or switches sure sounds nice. These seasonal panels could mount almost vertical and would provid emergency power if needed.
for thermal connection in diy immersion elements(tubes for example) you could use hexagonal boron nitride powder (NOT the cubic form which is extremely hard and used in grinding and cutting applications) Hexagonal boron nitride is a white powder which is electrically insulating, thermally stable, non toxic and most important of all its thermal conductivity rivals that of copper. might sound like an exotic material but it can be had from aliexpress for like 20-25$ per 500g . a metal tube closed at one end filled with a diode string and the powder and then compacted to eliminate air pockets and ensure good thermal contact. Pretty similar in principle to how resistive immersion heaters are built.
@greygleam Hi, cutting edge stuff... thanks for sharing! I was looking to use magnesium oxide powder and a several other (must be non toxic) substances, but you're right on the mark.. just found some hexagonal boron nitride in small jars for sale! Thank you :D
I was also thinking of heat pipes
@kregloglowy I want to try that!
Im not sure if I missed something here run the solar pannel through a series of diodes and use the emmiting heat. The voltage drops after passing througg the diode by at least .4 volt but often more ?
@ponemark Sounds right! I'd also add, match the voltage of the diode string to the vMP of the solar panel (like MPPT does). The voltage can vary, but it's easy to fix by adding or removing diodes
Could you add a thermostat to interrupt the circuit to avoid cooking the diodes and regulate the temperature?
@jestercrusher7743 Yes! I think 100C would be fine. Working on that now with appliance thermostats, but it takes time to test them
I am looking at making a Diode Aquarium heater.
@richardsandwell2285 Great idea - I am building a submersion element for a water tank. Trying some smaller diodes this time. With fish I imagine it would be important to control the temperature (thermostat control) very interesting to use solar for this
Is the power that is lost in the other options heating the panels? or is it just not produced by the panels?
@peterwright4656 In short, Nichrome resistance cannot regulate the solar panel to the most efficient voltage (that's what MPPT does) but oddly' enough a string of diodes behaves almost exactly the same as MPPT... so they can extract more heat under widely varying conditions
@@solarpoweredge I see, thanks for the reply.
@peterwright4656 NP
Maybe heaters full of silicone oil surrounding the diodes could be made.
@richardsandwell2285 Good idea! Building one for my water heating tank, just waiting for more parts
What about zenner diodes. It is possible to find powerful ones, which gives smaller amount of them, comparing to diodes. You can easily get them for any viltages. Even 48V for new solar panels or make series of them 4x12V to get smaller voltage or destribute power among them.
@iIiWARHEADiIi I will look for some zeners, definitely need to investigate and see what they can do
This is really good to see and very cool. It looks kinda dangerous for a DIY newbie like myself. However, I would like to know if there are similar options for an inverter system.
@ekeretteekpo3004 Hi! I'm glad you liked this paper... I never thought diodes should be used for heat... but new ideas take some getting used to :)
Regarding your question on inverters: we'd only want to connect diode strings straight to a solar panel - reason is, solar panels limit current and need regulation at a specific voltage. Batteries and inverters don't really limit current and would burn diodes up, BUT you can just use "normal resistive heaters" for those setups.
If you want to make pure heat cheap and direct from solar panels (no charge controller, no inverter, no battery to buy) diodes can really shine. This whole topic is honestly pretty confusing but I hope my reply is at least a little helpful :D any questions feel free to ask! -Dave
@@solarpoweredge thank you for the quick response. I already have a solar system setup (a small one - 1KW) and, seeing how this is, was thinking of something that could work for it.
@ekeretteekpo3004 No problem :D
Hi. How do you regulate the temperature from getting to high and causing damage in your diode chain? Just a thermostat? Say someone placed a diode chain in a sand battery connected to a couple solar panels.
@Johnnyclean Hi, a thermostat would be a very reasonable way to regulate the temperature
IMAGINE…. (I work at a bakery, conveyor oven and all) …..using diode to bake or just to pre-heat the volume in oven before burning natural gas
Yes, paten it!
@peterxyz3541 Good thinking :D I always wondered, what about those steel mills and foundries requiring massive amounts of heat? Build a massive solar farm next door and short circuit it through the furnace. PV to load ! Cut your electric bills! Any remaining heat can come from the grid or gas, but only as needed
would transistors work? connect a thermo switch in series with the gate, and you dont have to deal with the amperage issue?
@L0615T1C Sure, it's worth trying! They cost more I think. Keep in mind, there are metal tabbed power diodes. I am using 50a bridge rectifiers to heat my workshop, they seem fairly tough (metal case) but slightly more expensive than axial components of course
How efficient are hot diodes vs a standard electric stove (240V AC)?
@Voidsworn Hi, one could say they are 100% efficient just like nichrome. Diode strings are only recommended for direct-connect solar electric operation, because solar panels need to stay at max power voltage (MPPT). Resistance wire cannot do that on its own. If you're running off 240v AC, standard resistance heat is still the way to go... hope that helps !
@@solarpoweredge when you say resistance heat, what do you mean? Can you recommend devices based on that? Are there cheaper alternatives that are also as efficient?
@ekeretteekpo3004 Hi, the most common type of electric heating element is literally just an electric resistor. It may be a piece of nichrome wire, a metal bar, ceramic plates, but no matter what it's just a resistor.
*A resistor has Impedance (aka resistance) and it resists the flow of current, causing it to get very hot at a certain voltage. All electrical heating elements are technically 100% efficient, meaning you put in 100 watts, you get 100 watts of heat.
*But when using only a solar panel to make heat, resistance heating elements don't work too well, and cannot keep the solar panel at the proper voltage to maximize heat. They lose a lot of heat as a result, it's never captured.
*It just so happens a string of diodes can regulate the proper voltage of a solar panel, and they get hot, so they beat standard resistance heaters for direct-connected solar electric heating.
*Diodes are not resistors, and may seem to behave a bit strange. They have no significant resistance to current. They regulate themselves, unlike a resistor element.
*I do not know of any cheaper alternative besides diodes for direct solar electric heat. An MPPT converter will behave similarly, but it cost a lot of money versus cheap diodes.
Here's an example of a resistor cooking food my mini PV DC oven - it's direct solar driven but still works. It has insulation to improve efficiency.
ruclips.net/video/qj-sa0bZPCw/видео.html
Here's a DIY mini 12 volt oven build using resistance heating, doesn't use much power but cooks food easily:
ruclips.net/video/z0dKupye594/видео.html
Another resistance based oven that runs on 18v power tool batteries:
ruclips.net/video/SLiwNnHPlI0/видео.html
Simply put, with battery power, we can use a resistor for heat - it's 100% efficient. With solar power, we can use a resistor (doesn't work as well) OR diodes (works better if properly configured).
I hope this is helpful. My aim is to share knowledge and information, even if it's not quite mainstream - diode strings are still very obscure and unknown.
@@solarpoweredgethank you. I'll check out the video of the DIY mini 12V oven build...
By the way, are they called resistance heating cookers?
@ekeretteekpo3004 No problem! yes that term is technically correct. (because they use a resistance heating element to produce the heat from voltage and cook the food)
What about using direct solar to power 120v infrared light bulbs as an ultra simple heat source? I have (4)120w 20v panels I could arrange in series/parallel to produce 480w at 60v dc to power an 300w infrared bulb.
@803mastiff9 Solar panels can run a resistive load (like an infrared bulb) no problem.. I will buy some of those infrared bulbs to test
@solarpoweredge I am going to explore this as well. Lowes carries a dimmable ceramic heater bulb. Easy Bake Ovens use a 100w lightbulb to bake their cakes.
@803mastiff9 Great... I ordered a set of ordinary infrared bulbs last night, it just so happens I will have a metal box to put them in too. I am interested to see what they could do
Ceramic heating elements tend to increase their resistance as the temperature increases, which could be a good thing. And there are 12 volt elements available too.
@jima3252 Right on... that also helps increase safety... those ceramic (PTC) heaters are pretty awesome! I used some to heat the back room with 2 and later 4 100w solar panels. Was really surprised how much difference the setup made... 2 thin wires to get all that heat inside...
Found some of the videos showing PTCs
ruclips.net/video/UxgINFgqUoI/видео.html
ruclips.net/video/wK3_lRSntRc/видео.html