I have been off grid for 7 years now in CA. My system uses 76kwh's of chevy volt batteries broken down to 48v packs. The 12kw Yiyen built inverter runs my 3bd 2ba 1700sq ft house just fine. My 6kw inverter charges my chevy volt car. My used 16000w solar work just fine. I do have 3000w of panels running micro inverters as a AC coupled experiment. I found when I not using much power my 12kw inverter will charge my chevy volt batteries from that source of solar power. I run a 3ton AC set to 72F years round. Other loads include 1.5hp well pump. 5hp air compressor, Miller mig welder. And the hardest thing to start is my 7hp pressure washer. It can be done but you need $$$ to do it. 35k in my system parts. Easy 20k of labor in my system.
Also using Home Assistant, in cooperation with g-e charger. Works great. Switches to 3phase if I have more than 4kW of solar excess, to charge as fast as possible. I can also set a "minimum return" - no matter what, I will feed back to the grid this amount before the charging is even considered - I use this to address "short term jumps" in consumption. Works amazing, so far I've charged excess of 2MWh since April solely from the sun, saving the purchase of 680 liters of Putin-juice, so well worth of the effort and investment.
You have a nice setup, the open source stuff is awesome. We have Enphase, with their battery storage. With the need to charge one car nightly for work, I don’t think it will ever be possible to charge without grid power. Our battery system is not large enough to charge either car all on its own. The best we can do is charge one car during the day when necessary since the second car is not used daily.
I swapped the peak and off-peak times of day in the Bolt system settings, so daylight hours are now "off-peak," and changed it to charge "off-peak only" on the scheduled section (with different hours for summer vs winter). It's crude but it does the job, even though it doesn't account for power generation and clouds. But it was also free with no extra parts and minimal time effort.
I planned two years and a half years in advance before i got my Ford F150 Lightening. I installed 14.6Kw worth of panels on my house for an average of 70Kw generated per day. The solar covers all our power use as well as selling about 50Kw back to the power company. After doing the math, optimal chrage rates on my level 2 charger is 32 amps and charging during the day between 10:00 and 16:00 to keep all my EV charging via my panels. I set the Lightening to only charge during those hours. I made the suggestion to Ford they incorporate a charge only during sunny moments using the existing sensors for a "green" charging option. Im going to look into the open source stuff though. Thanks for the great info.
If you have SolarEdge hardware since the introduction of the HD-Wave inverter without a screen, you can hardwire a SolarEdge EVSE directly to the Inverter -- no separate circuit -- and charge from your choice of directly from the PV or a combination of PV+grid power. The SolarEdge EVSE can also be hardwired to a circuit of plugged in just like a normal EVSE.
Built myself a ground based wooden framework for my panels as they don't have to be on the roof and they don't have to use fancy, expensive mouting rails. I also created a battery of individual lithium cells rather than a pre-manufactured battery. I use this to charge my Nissan Leaf with a level 2 charger and to power some circuits in my house.The solar is independent of the grid.
I have had internet problems this week so I only just got to watching this video. Australia has such a high rate of roof top solar is that if the sun is out the grid is running very high on solar power. Here in spring when its not too hot it gets up to 80%. My mum has been basically plugging the car in whenever the sun is up. The straight up connection was too expensive, so did go with the Zappi :).
If you have all electric hvac, running your home on 100% solar is rarely achievable. We have air source heat pump (geothermal not possible), heat pump water heater, maximum rooftop solar, newer windows, maximum insulation and sealing and we are grandfathered in for net metering for 5 more years. Never came close to a negative electric bill or even zero. We charge our EV (leased Bolt then Tesla model Y) mostly at home.
I have a Solar Edge solar system and inverter. The inverter has an outlet on it for an EV charging cable. I just plug the cable into the inverter and charger the car from there. The inverter uses a solar energy boost to charge the car at a higher rate during a sunny day than at night. The gain is from just under 8kw to about 9.6kw. The $500 cable was a lot less than needing to install a separate level 2 charger and a cable to use with that, at least a $500 savings. Since I had the solar system 2 years prior to getting the EV and the inverter already had the charging capability I didn’t need to buy a new inverter todo this anyway.
This is quite interesting! I had no idea that this control was available. I have Sunpower microinverters - where can I find out if these are supported?
I'm interested in doing a camper conversion on one of the new eSprinters. I'm wondering what my options will be for using solar panels (van roof array and possible a ground array also) to charge the main vehicle battery. The usual approach for an ICE van is to connect the panels to a solar charge controller and in turn to the van battery system (for van lighting, air conditioning, stove, etc.). I'm wondering if it will be possible to connect the solar charge controller to an EV charger. These of course are AC so there would have to be an inverter involved. On the other hand, the output of the charge controller is DC which powers lights and many other things directly. This is more efficient since converting DC to AC involves some energy loss. It would be great if it were possible to charge the main vehicle battery with DC. This would be low voltage DC as opposed to high voltage DC at a level 3 charger. Maybe no possible? Any thoughts (about any part of this) would be much appreciated.
My personal open-source setup: The excellent EVCC on a RaspberryPi - It queries the vehicle APIs for charge status - it gets grid consumption and production from two brands of inverters (soon to be more APIs) - Depending on the detected vehicle it changes charging limits - It also switches from 1 to 3 phase power on the fly if desired (and supported by the EVSE and vehicle. Don't blow up any Renault Zoes!) In parallel I also have an Installation of TeslaSolarCharger (integrated with TeslaMate) running. While it isn't brand agnostic obviously it also allows to adjust charging currents with dumb EVSEs via the vehicle API
I just added a high value resistor to the charger PP sense line so that it only outputs 1.6 kw. Because usually my solar only outputs 2kw or less. Or could just use a granny cable when the sun is shining
My wireless electricity meter transmits my energy consumption/production to the power company, is there any way to tap into that signal? That way it could take into account both solar panels and loads in the home, no?
Myenergi have a solar ev charger in the UK called Zappi, it contains many of the features you talk about here. The only downside is it doesn't have the ability to set the power level and power transferred to the ev in kwh (this is a pain if you have a house battery that has discharge limits and you want to deplete power level say to 20% before going on a trip).
All of the "solar EV Charging" solutions described so far depend on being connected to the Grid, or needing stationary battery storage. Missing is an off-grid EV charging solution that doesn't require an intermediate storage battery. Ideally one could charge the EV directly from solar panels using DC power and a charge controller. Unfortunately, our EVs DC charging need a minimum amount of power that is more than can be delivered by a reasonable sized PV array. If you're going to charge the EV using level 2 AC without the grid or battery storage, charging will likely be intermittent as PV power will fluctuate above and below the power demand of the on board EV charger.
So i do this as best as my budget allows. I have a pi3b running HA. A dumb podpoint evse upgraded using a shelly relay in the cp line allowing me to turn it on when i need from HA. Its a course grain method where i turn on whenever my export (measured using a different shelly em device) it hitting a certain level approx 2.5kw because i want to put power in the env200/outlander whenever its price parity with the grids night rate or better. I have a turn off rule run every mins to ensure that overcast intermittant sun does turn my car and evses relays too often. The energy page on ha is brill for tracking all this. I may put a esp32 based device in my van to control its on board charger to export match more closely. That is a project for future me. I also have a lifepo4 battery running a soyosource gtn1000w which too integrates with HA and gives me 3kwh of baseload removal when the sun has gone down. All this is to say you dont need to spend mega money to catch most of the solar you make. Thanks for showing people the HA way its about time people raved less about the $£€ ways of saving money and started being more realistic and pragmatic for the majority who don't have money to save money.
That is quite an innovative solution, interrupting the CP line. It is unclear, though, whether that is a sufficient soft-stop since the EVSE may just think you unplugged and cut-off charging while the vehicle is still pulling full amps. If that is what is happening it will still put excessive wear on the electrical path.
@@junkerzn7312 yep its definately not ideal. It maybe requires a rethink. To be fair, its not like you cant disconnect a plug at near full amps its only as bad as that. Usually when its sunny enough its sunny for hours and by the end of the day the obc isnt pulling top amps anyway. Also its only a 3.7kw charger, i dont have the solar for 6.6kw
@@Whereswally606 There is a fairly big difference between occasional manual disconnects and automated disconnects that might run through many cycles under load over the years. I advise caution. As a side note, this is why many devices... electric water heaters, A/C systems, inverters, and so forth, have separate disable/enable control inputs to allow for external power control. I'm sure numerous EVSE's have such inputs too, but I have not researched it. Probably the best bet is to get an EVSE that can be directly integrated into home assistant via WiFi. You can google up a list of EVSEs that are directly compatible with home assistant's OpenEVSE API. -Matt
Where you live and what and how much you drive are major factors. Of course time of year is also a huge factor. Here in Maine, my solar array produces an average of about 1 KWh per kilowatt of solar panels from late November through January. That assumes I can keep my panels snow free, which is often not possible. If I was driving 40 miles per day in a car that got 2.5 miles per kilowatt-hour, I would need 40/2.5=16 kilowatt-hours day to keep the car charged. That would require a 16 kilowatt array in winter and a minimum 4 kilowatt array in summer assuming I wasn't using any power in the house and the process from panels to EV was 100% efficient. If I needed to charge at night, 16 hours per day in winter, I would need at least a 16 KWh battery pack. Also, given our weather there are lots of days, particularly in winter when solar production is much lower than the typical average power production. Those days would produce a deficit that would be hard to make up. Basically, in a place like Maine, while charging an EV from solar is possible if you have a big enough array, in winter it would be very challenging. Also if you include household usage the required array size goes up significantly. In my specific case, the minimum array to power my house in winter is about 8 kilowatts so adding an EV, driven 40 miles per day would require at least a 24 kilowatt array. An array that size gets very pricey and here would require a lot of maintenance (snow removal) to keep it running. This situation is not limited to Maine, pretty much anywhere above 40 degrees north latitude will have similar issues.
Yes, you explained the up North off-grid solar problem well. Does your utility allow net metering? If so, the extra energy you produce in Summer will be credited to you in the Winter at no cost to you. So you only need enough solar power to produce your year-round average energy to break even, not the size you'd need for the worse months.🤓
@@fotoguru222 Yes the utility allows net metering on a 12 month rolling basis, so any credit older than 12 months goes away. However, our billing has two parts - energy charges and transmission charges. You pay the transmission charge both ways, so the net credit is only about 15% of the total charge. (currently $0.305/KWh). That is why my system is not grid tied. My system is primarily for power outages with battery storage and a 10 circuit transfer switch so that my solar/battery output never touches the grid. I don't have room on my roof for a big enough system to replace all my power use without an EV even in summer. That is due to an east-west oriented roof and a neighbor that won't, under any circumstances trim their trees that shade my roof more each year. In summer I run my largest loads (fridge and freezer) from solar, but I don't get enough production for that in winter when the system is used only for outages.
Emporia EVSE plus Emporia Vue energy monitor can dynamically adjust charge rate based on excess solar output. They're also quite inexpensive and high quality.
This is what we have and it’s fantastic. You can get a Vue and EVSE for less than $600. It’s a 48 amp EVSE to boot. Simple to setup and also gives you home energy monitoring.
The basic problem with dynamic algorithms is that you just don't know how much charge your vehicle will get. It can be unexpectedly smaller than what you actually need. And yes, sure, you can try programming the smart systems with sophisticated parameters. But it just won't fit every situation. In otherwords, these dynamic systems are going to cause pain. Generally speaking you want the vehicle to charge at a set rate. That way you know precisely how much range you are getting without having to monitor anything. No smart equipment is really needed... just adjust your EVSE to cap the charge rate at something you know your solar system or solar + battery system can produce on a sunny day and plug in during that period. If you find yourself in need of charging and not able to plug in at the right time, then you just plug in anyway and punt on trying to balance your energy use for that day. This really is the most reliable solution. And I say this as a person who has a very heavily integrated home-assistant based system myself, home solar, and an EV. I just reduce the charge rate programmed into my EVSE to roughly 7kW and I plug in in the middle of the day when charging is needed, whenever it is convenient to do so and that's it. The west-coast grid, for example, is guaranteed to be heavily stacked towards solar when the sun is shining. -- I will say that generally speaking one should NOT, I repeat NOT put repurposed EV battery packs in or near your home or garage, unless they are LFP packs. And even then, they have to be pristine. I know there are a lot of RUclips channels and such that show people how to do it. I like to watch them too. Will Prowse, DavidPoz, Jehugarcia... all great channels. But you have to take care once you start pushing real amps. A lot of care. As an electrical engineer and lithium battery expert, DO NOT DIY USED NMC/NCA EV BATTERY PACKS! EVER! Doing so results in an extreme risk to your home. They are virtually never vented or firewalled properly in DIY installations and the BMS comms are typically incomplete... just good enough to charge and discharge and not much more. Damage can be hidden, particularly shock damage, and NMC/NCA chemistries just aren't robust enough, even with the individual cell fusing EV packs typically have, to risk DIY re-use. I think DIY'ing LFP batteries is fine as long as you know enough about power electronics to wire, fuse, and breaker it properly. And situate it properly for fire safety and venting. Never rely on the BMS... the BMS is always your last line of defense, not your main line of defense. And to be honest, once you are north of 100A or so of operating current, things become really serious and you need to have an actual electrician take a hard look at what you have done. My word of advice.
I am pretty sure I have read about EVSE for North America that adjust charge rate to use whatever excess solar that you panels are producing, above household consumption, and adjust EV charging rate to use the excess without drawing from the grid. It would have been great if Nikki had listed one or two of them. The Zappi is only available for use with European and UK electric service. Edit: After reading some of the other comments, I am going to checkout the Solar Edge EVSE. It sounds like you also need a Solar Edge inverter for your PV system though. I think the Zappi will work with any PV system, all that is needed are current measuring clamps for both solar inverter output and total household load.
If you intend to charge an EV with a standalone (off grid) or emergency backup power solar system. It's important to consider the technology that's used in the inverter. High frequency, transformerless inverters provide a much lower surge capacity and a shorter life expectancy than heavy duty, low frequency, transformer based inverters. Additionally. high frequency, transformerless inverters do not provide any galvanic isolation between its DC boost stage circuitry and its AC output which can allow high amperage DC current to pass through to your EV's onboard charger and damage it. You may be able to use a high frequency inverter to charge an EV short term, but it would just a matter of time before the MOSFETs or IGBTs in this inverter fail and you can kiss your EV's onboard charger goodbye. A much better and safer choice if you want to charge your EV with solar is to use an inverter or power station that uses low frequency, transformer based technology in its design. Low frequency inverters can handle high surge loads for at least 3x their continuous rated capacity and they can do this repeatedly, without sustaining damages to their MOSFET transistors, for minutes, rather than the milliseconds that a high frequency inverter offers. And because low frequency inverters use a transformer, they provide galvanic isolation which protects your EV's charger. That's why the big name brand inverter manufacturers like Schneider Electric, Outback Power, Sigineer Power, Magnum Energy and Victron Energy and others, all use a low frequency topology in their design.
Also my situation. I may yet add batteries as the tax credit is good until 2030. But in 2022 I earned about $225 and have another 18 years of NEM 2.0, so there is no rush.
We are in process of buying a home here in Oregon. My current initial plan is to start our solar journey by building a car port with solar panels which will power the trickle charger that came with our EV. Then look into adding the EV battery as our initial house battery. This is all only a rough conceptual plan at this point. Has anyone here tried such a thing yet? BTW, I've been a Home Assistant user for years so it will be part of the solution in some way. 😁
Without a battery or grid buffer charging directly from the solar panels can be finicky. The car can stop charging if the panels get shaded for any reason.
@@economicprisoner I'm planning on micro inverters to help mitigate the tree shadow issue. Thanks for the trip. I now see the wisdom of adding at least a small amount of battery storage to act as a buffer to smooth out dips Sun light.
I am off-grid and want to use excess solar to charge my EV but the zappi charger relies on detecting excess solar power being exported and diverting that amount of power into the EV. Ideally I would like a DC charger powered directly by my PV but they seem prohibitively expensive.
I'm not sure I'd trust having triggers from an Internet server. My Internet drops out so often it would probably ly get stuck charging all night when the panels had no output.
Makes no sense unless you can plug EV directly into a solar array, current concept of store the power, convert to AC, have car reconvert it back to DC just makes no sense....this EV stuff was not well thought out at all.
I fear your logic around Grid CO2 emissions may not be valid. Unless the Grid is producing excess Green Electricity, the extra electricity used to charge your car will be generated by Fossil Fuel, no matter what the value of the Grid CO2 emissions. Unfortunately your logic around purchasing green electricity from a supplier may also be flawed. All it may do, is make everyone else's electricity that little bit less green. Reduction in usage is the greenest option.
I think this is a reasonable question but may be making some assumptions unnecessarily. If you are using a whole day's solar production to charge your vehicle, and then running your house off mixed grid, then what would the benefit be? This would be a fruitless trade-off. I think, though, you don't have to use the whole day's solar power. In broad terms, if you produce 25kWh per day, and need 15 for your home, there's nothing to say you have to use more than the last 10kWh for your vehicle. If you average 21 miles of driving per day, and your vehicle averages 3 kWh, then you only used 7kWh, and the additional 3kWh will still get you more full than you started that day. Just remember, you don't have to charge everything to 100%. And for the sake of discussion, even if you drove 42 miles per day, and your 100% charge dwindled more each day even with 10kWh replacement, you could still have recharged for nearly 3 weeks (240 mile battery), before going to pay for a grid full charge top off. By managing your usage, you CAN offload demand of the grid and indeed reduce carbon footprint. Regarding making the grid dirtier, that may be a short term response, but the market will see that people will want to buy renewable power directly, or else they will install solar and stop paying. If I'm a corporation I would want to offer renewable power to customers, rather than lose said customers from the grid.
@@jamesl1332The suggestion in the video was to select Green energy if you don't have solar panels. I think this may be questionable. Yes, it is good to signal to Electricity Suppliers that Green is good, but most consumers think price is better.
Instead of installing battery storage in your home how about buying a second hand Nissan LEAF and not using it as a car. The LEAF can put power back into your house and the second hand price is about 15,000 euros. But there is zero installation. You buy the car second hand and it works. Your house will need some sort of home intergration system, but the battery part doesn't need installing. And if you have a power cut for a month or more then your home battery is on wheels and you can transport your electricity to yourself in extreme power cuts.
I have been off grid for 7 years now in CA.
My system uses 76kwh's of chevy volt batteries broken down to 48v packs. The 12kw Yiyen built inverter runs my 3bd 2ba 1700sq ft house just fine. My 6kw inverter charges my chevy volt car. My used 16000w solar work just fine. I do have 3000w of panels running micro inverters as a AC coupled experiment. I found when I not using much power my 12kw inverter will charge my chevy volt batteries from that source of solar power.
I run a 3ton AC set to 72F years round. Other loads include 1.5hp well pump. 5hp air compressor, Miller mig welder. And the hardest thing to start is my 7hp pressure washer. It can be done but you need $$$ to do it. 35k in my system parts. Easy 20k of labor in my system.
Also using Home Assistant, in cooperation with g-e charger. Works great. Switches to 3phase if I have more than 4kW of solar excess, to charge as fast as possible. I can also set a "minimum return" - no matter what, I will feed back to the grid this amount before the charging is even considered - I use this to address "short term jumps" in consumption.
Works amazing, so far I've charged excess of 2MWh since April solely from the sun, saving the purchase of 680 liters of Putin-juice, so well worth of the effort and investment.
You have a nice setup, the open source stuff is awesome. We have Enphase, with their battery storage. With the need to charge one car nightly for work, I don’t think it will ever be possible to charge without grid power. Our battery system is not large enough to charge either car all on its own. The best we can do is charge one car during the day when necessary since the second car is not used daily.
I swapped the peak and off-peak times of day in the Bolt system settings, so daylight hours are now "off-peak," and changed it to charge "off-peak only" on the scheduled section (with different hours for summer vs winter). It's crude but it does the job, even though it doesn't account for power generation and clouds. But it was also free with no extra parts and minimal time effort.
I planned two years and a half years in advance before i got my Ford F150 Lightening. I installed 14.6Kw worth of panels on my house for an average of 70Kw generated per day. The solar covers all our power use as well as selling about 50Kw back to the power company. After doing the math, optimal chrage rates on my level 2 charger is 32 amps and charging during the day between 10:00 and 16:00 to keep all my EV charging via my panels. I set the Lightening to only charge during those hours. I made the suggestion to Ford they incorporate a charge only during sunny moments using the existing sensors for a "green" charging option. Im going to look into the open source stuff though. Thanks for the great info.
If you have SolarEdge hardware since the introduction of the HD-Wave inverter without a screen, you can hardwire a SolarEdge EVSE directly to the Inverter -- no separate circuit -- and charge from your choice of directly from the PV or a combination of PV+grid power.
The SolarEdge EVSE can also be hardwired to a circuit of plugged in just like a normal EVSE.
Built myself a ground based wooden framework for my panels as they don't have to be on the roof and they don't have to use fancy, expensive mouting rails. I also created a battery of individual lithium cells rather than a pre-manufactured battery. I use this to charge my Nissan Leaf with a level 2 charger and to power some circuits in my house.The solar is independent of the grid.
I assume you had to get planning permission for the ground based solar panels? (UK anyhows).
That's the smart economical format, off roof, off grid
I have had internet problems this week so I only just got to watching this video. Australia has such a high rate of roof top solar is that if the sun is out the grid is running very high on solar power. Here in spring when its not too hot it gets up to 80%. My mum has been basically plugging the car in whenever the sun is up. The straight up connection was too expensive, so did go with the Zappi :).
I use a zappi on my enyaq. Works a treat. 7 months a year is 100% solar driving.
If you have all electric hvac, running your home on 100% solar is rarely achievable. We have air source heat pump (geothermal not possible), heat pump water heater, maximum rooftop solar, newer windows, maximum insulation and sealing and we are grandfathered in for net metering for 5 more years. Never came close to a negative electric bill or even zero. We charge our EV (leased Bolt then Tesla model Y) mostly at home.
Are you saving enough to offset the investment?
I have a Solar Edge solar system and inverter. The inverter has an outlet on it for an EV charging cable. I just plug the cable into the inverter and charger the car from there. The inverter uses a solar energy boost to charge the car at a higher rate during a sunny day than at night. The gain is from just under 8kw to about 9.6kw. The $500 cable was a lot less than needing to install a separate level 2 charger and a cable to use with that, at least a $500 savings. Since I had the solar system 2 years prior to getting the EV and the inverter already had the charging capability I didn’t need to buy a new inverter todo this anyway.
This is quite interesting! I had no idea that this control was available. I have Sunpower microinverters - where can I find out if these are supported?
Really informative. This is such a cool application for Home Assistant!
I'm interested in doing a camper conversion on one of the new eSprinters. I'm wondering what my options will be for using solar panels (van roof array and possible a ground array also) to charge the main vehicle battery. The usual approach for an ICE van is to connect the panels to a solar charge controller and in turn to the van battery system (for van lighting, air conditioning, stove, etc.). I'm wondering if it will be possible to connect the solar charge controller to an EV charger. These of course are AC so there would have to be an inverter involved. On the other hand, the output of the charge controller is DC which powers lights and many other things directly. This is more efficient since converting DC to AC involves some energy loss. It would be great if it were possible to charge the main vehicle battery with DC. This would be low voltage DC as opposed to high voltage DC at a level 3 charger. Maybe no possible? Any thoughts (about any part of this) would be much appreciated.
My personal open-source setup:
The excellent EVCC on a RaspberryPi
- It queries the vehicle APIs for charge status
- it gets grid consumption and production from two brands of inverters (soon to be more APIs)
- Depending on the detected vehicle it changes charging limits
- It also switches from 1 to 3 phase power on the fly if desired (and supported by the EVSE and vehicle. Don't blow up any Renault Zoes!)
In parallel I also have an Installation of TeslaSolarCharger (integrated with TeslaMate) running. While it isn't brand agnostic obviously it also allows to adjust charging currents with dumb EVSEs via the vehicle API
I really want to know how a simple DC2DC is done... A few Kw would be fine.
I want to charge my Lightning with off grid solar. Is all I need solar panels and an mppt?
I just added a high value resistor to the charger PP sense line so that it only outputs 1.6 kw. Because usually my solar only outputs 2kw or less. Or could just use a granny cable when the sun is shining
My wireless electricity meter transmits my energy consumption/production to the power company, is there any way to tap into that signal? That way it could take into account both solar panels and loads in the home, no?
I love that you have a PowerBook G3 in the background!
Myenergi have a solar ev charger in the UK called Zappi, it contains many of the features you talk about here. The only downside is it doesn't have the ability to set the power level and power transferred to the ev in kwh (this is a pain if you have a house battery that has discharge limits and you want to deplete power level say to 20% before going on a trip).
All of the "solar EV Charging" solutions described so far depend on being connected to the Grid, or needing stationary battery storage. Missing is an off-grid EV charging solution that doesn't require an intermediate storage battery. Ideally one could charge the EV directly from solar panels using DC power and a charge controller. Unfortunately, our EVs DC charging need a minimum amount of power that is more than can be delivered by a reasonable sized PV array. If you're going to charge the EV using level 2 AC without the grid or battery storage, charging will likely be intermittent as PV power will fluctuate above and below the power demand of the on board EV charger.
So i do this as best as my budget allows. I have a pi3b running HA. A dumb podpoint evse upgraded using a shelly relay in the cp line allowing me to turn it on when i need from HA. Its a course grain method where i turn on whenever my export (measured using a different shelly em device) it hitting a certain level approx 2.5kw because i want to put power in the env200/outlander whenever its price parity with the grids night rate or better. I have a turn off rule run every mins to ensure that overcast intermittant sun does turn my car and evses relays too often. The energy page on ha is brill for tracking all this. I may put a esp32 based device in my van to control its on board charger to export match more closely. That is a project for future me. I also have a lifepo4 battery running a soyosource gtn1000w which too integrates with HA and gives me 3kwh of baseload removal when the sun has gone down. All this is to say you dont need to spend mega money to catch most of the solar you make. Thanks for showing people the HA way its about time people raved less about the $£€ ways of saving money and started being more realistic and pragmatic for the majority who don't have money to save money.
That is quite an innovative solution, interrupting the CP line. It is unclear, though, whether that is a sufficient soft-stop since the EVSE may just think you unplugged and cut-off charging while the vehicle is still pulling full amps. If that is what is happening it will still put excessive wear on the electrical path.
@@junkerzn7312 yep its definately not ideal. It maybe requires a rethink. To be fair, its not like you cant disconnect a plug at near full amps its only as bad as that. Usually when its sunny enough its sunny for hours and by the end of the day the obc isnt pulling top amps anyway. Also its only a 3.7kw charger, i dont have the solar for 6.6kw
@@Whereswally606 There is a fairly big difference between occasional manual disconnects and automated disconnects that might run through many cycles under load over the years. I advise caution.
As a side note, this is why many devices... electric water heaters, A/C systems, inverters, and so forth, have separate disable/enable control inputs to allow for external power control. I'm sure numerous EVSE's have such inputs too, but I have not researched it.
Probably the best bet is to get an EVSE that can be directly integrated into home assistant via WiFi. You can google up a list of EVSEs that are directly compatible with home assistant's OpenEVSE API.
-Matt
Where you live and what and how much you drive are major factors. Of course time of year is also a huge factor. Here in Maine, my solar array produces an average of about 1 KWh per kilowatt of solar panels from late November through January. That assumes I can keep my panels snow free, which is often not possible. If I was driving 40 miles per day in a car that got 2.5 miles per kilowatt-hour, I would need 40/2.5=16 kilowatt-hours day to keep the car charged. That would require a 16 kilowatt array in winter and a minimum 4 kilowatt array in summer assuming I wasn't using any power in the house and the process from panels to EV was 100% efficient. If I needed to charge at night, 16 hours per day in winter, I would need at least a 16 KWh battery pack. Also, given our weather there are lots of days, particularly in winter when solar production is much lower than the typical average power production. Those days would produce a deficit that would be hard to make up. Basically, in a place like Maine, while charging an EV from solar is possible if you have a big enough array, in winter it would be very challenging. Also if you include household usage the required array size goes up significantly. In my specific case, the minimum array to power my house in winter is about 8 kilowatts so adding an EV, driven 40 miles per day would require at least a 24 kilowatt array. An array that size gets very pricey and here would require a lot of maintenance (snow removal) to keep it running. This situation is not limited to Maine, pretty much anywhere above 40 degrees north latitude will have similar issues.
Yes, you explained the up North off-grid solar problem well.
Does your utility allow net metering? If so, the extra energy you produce in Summer will be credited to you in the Winter at no cost to you. So you only need enough solar power to produce your year-round average energy to break even, not the size you'd need for the worse months.🤓
@@fotoguru222 Yes the utility allows net metering on a 12 month rolling basis, so any credit older than 12 months goes away. However, our billing has two parts - energy charges and transmission charges. You pay the transmission charge both ways, so the net credit is only about 15% of the total charge. (currently $0.305/KWh). That is why my system is not grid tied. My system is primarily for power outages with battery storage and a 10 circuit transfer switch so that my solar/battery output never touches the grid. I don't have room on my roof for a big enough system to replace all my power use without an EV even in summer. That is due to an east-west oriented roof and a neighbor that won't, under any circumstances trim their trees that shade my roof more each year. In summer I run my largest loads (fridge and freezer) from solar, but I don't get enough production for that in winter when the system is used only for outages.
I had a SolarEdge ev charger installed that is supposed to use excess solar
It’s never worked correctly to do this and is frankly frustrating
Emporia EVSE plus Emporia Vue energy monitor can dynamically adjust charge rate based on excess solar output. They're also quite inexpensive and high quality.
This is what we have and it’s fantastic. You can get a Vue and EVSE for less than $600. It’s a 48 amp EVSE to boot. Simple to setup and also gives you home energy monitoring.
Depending upon where you live, i think with a large enough solar system with home battery, it is achievable.
The basic problem with dynamic algorithms is that you just don't know how much charge your vehicle will get. It can be unexpectedly smaller than what you actually need. And yes, sure, you can try programming the smart systems with sophisticated parameters. But it just won't fit every situation. In otherwords, these dynamic systems are going to cause pain.
Generally speaking you want the vehicle to charge at a set rate. That way you know precisely how much range you are getting without having to monitor anything. No smart equipment is really needed... just adjust your EVSE to cap the charge rate at something you know your solar system or solar + battery system can produce on a sunny day and plug in during that period. If you find yourself in need of charging and not able to plug in at the right time, then you just plug in anyway and punt on trying to balance your energy use for that day. This really is the most reliable solution.
And I say this as a person who has a very heavily integrated home-assistant based system myself, home solar, and an EV. I just reduce the charge rate programmed into my EVSE to roughly 7kW and I plug in in the middle of the day when charging is needed, whenever it is convenient to do so and that's it. The west-coast grid, for example, is guaranteed to be heavily stacked towards solar when the sun is shining.
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I will say that generally speaking one should NOT, I repeat NOT put repurposed EV battery packs in or near your home or garage, unless they are LFP packs. And even then, they have to be pristine.
I know there are a lot of RUclips channels and such that show people how to do it. I like to watch them too. Will Prowse, DavidPoz, Jehugarcia... all great channels. But you have to take care once you start pushing real amps. A lot of care.
As an electrical engineer and lithium battery expert, DO NOT DIY USED NMC/NCA EV BATTERY PACKS! EVER! Doing so results in an extreme risk to your home. They are virtually never vented or firewalled properly in DIY installations and the BMS comms are typically incomplete... just good enough to charge and discharge and not much more. Damage can be hidden, particularly shock damage, and NMC/NCA chemistries just aren't robust enough, even with the individual cell fusing EV packs typically have, to risk DIY re-use.
I think DIY'ing LFP batteries is fine as long as you know enough about power electronics to wire, fuse, and breaker it properly. And situate it properly for fire safety and venting. Never rely on the BMS... the BMS is always your last line of defense, not your main line of defense. And to be honest, once you are north of 100A or so of operating current, things become really serious and you need to have an actual electrician take a hard look at what you have done.
My word of advice.
Yes, Electricity and Plumbing are dangerous and should always be left to the experts.
2.7 kW of Solar panels will get you around 70 Klms or 40 miles of charge a Day.
I am pretty sure I have read about EVSE for North America that adjust charge rate to use whatever excess solar that you panels are producing, above household consumption, and adjust EV charging rate to use the excess without drawing from the grid. It would have been great if Nikki had listed one or two of them. The Zappi is only available for use with European and UK electric service.
Edit: After reading some of the other comments, I am going to checkout the Solar Edge EVSE. It sounds like you also need a Solar Edge inverter for your PV system though. I think the Zappi will work with any PV system, all that is needed are current measuring clamps for both solar inverter output and total household load.
Yes but the SolarEdge system doesn’t do what they claim
I’ve had it for over a year and it’s never done what they promise
I look for a string wallbox charger basically a mppt charger with software integration. to charge on carport solar array with no wires to any where.
DIY home battery sounds great until your insurance company or building inspector deny your claim or permit respectively.
If you intend to charge an EV with a standalone (off grid) or emergency backup power solar system. It's important to consider the technology that's used in the inverter. High frequency, transformerless inverters provide a much lower surge capacity and a shorter life expectancy than heavy duty, low frequency, transformer based inverters. Additionally. high frequency, transformerless inverters do not provide any galvanic isolation between its DC boost stage circuitry and its AC output which can allow high amperage DC current to pass through to your EV's onboard charger and damage it. You may be able to use a high frequency inverter to charge an EV short term, but it would just a matter of time before the MOSFETs or IGBTs in this inverter fail and you can kiss your EV's onboard charger goodbye. A much better and safer choice if you want to charge your EV with solar is to use an inverter or power station that uses low frequency, transformer based technology in its design. Low frequency inverters can handle high surge loads for at least 3x their continuous rated capacity and they can do this repeatedly, without sustaining damages to their MOSFET transistors, for minutes, rather than the milliseconds that a high frequency inverter offers. And because low frequency inverters use a transformer, they provide galvanic isolation which protects your EV's charger. That's why the big name brand inverter manufacturers like Schneider Electric, Outback Power, Sigineer Power, Magnum Energy and Victron Energy and others, all use a low frequency topology in their design.
Thank you! Great info., as usual.
We have net metering and solar only, though we may do batteries in the future.
Also my situation. I may yet add batteries as the tax credit is good until 2030. But in 2022 I earned about $225 and have another 18 years of NEM 2.0, so there is no rush.
We are in process of buying a home here in Oregon. My current initial plan is to start our solar journey by building a car port with solar panels which will power the trickle charger that came with our EV. Then look into adding the EV battery as our initial house battery. This is all only a rough conceptual plan at this point. Has anyone here tried such a thing yet?
BTW, I've been a Home Assistant user for years so it will be part of the solution in some way. 😁
Without a battery or grid buffer charging directly from the solar panels can be finicky. The car can stop charging if the panels get shaded for any reason.
@@economicprisoner I'm planning on micro inverters to help mitigate the tree shadow issue. Thanks for the trip. I now see the wisdom of adding at least a small amount of battery storage to act as a buffer to smooth out dips Sun light.
Thank you
I am off-grid and want to use excess solar to charge my EV but the zappi charger relies on detecting excess solar power being exported and diverting that amount of power into the EV. Ideally I would like a DC charger powered directly by my PV but they seem prohibitively expensive.
I'm not sure I'd trust having triggers from an Internet server. My Internet drops out so often it would probably ly get stuck charging all night when the panels had no output.
Home assistant is all locally-based - Nikki
Now that Electify America has started up their huge solar field in California, all you have to do is charge your EV at one of their sites.
DIY stuff is virtually always legal unless you connect it to the grid. So for something like EV charging- not a problem.
But is it safe?
What will your insurance company say?
Im not trying to throw shade here like your trees are doing to your solar panels..... but Why?
We don’t own the trees! - Nikki
@@transportevolved 👁 🌊
Makes no sense unless you can plug EV directly into a solar array, current concept of store the power, convert to AC, have car reconvert it back to DC just makes no sense....this EV stuff was not well thought out at all.
Lithium charging lithium is cold fusion
I have no automation at all. I just buy my electricity from a company that only delivers green electricity from wind and hydro.
I fear your logic around Grid CO2 emissions may not be valid.
Unless the Grid is producing excess Green Electricity, the extra electricity used to charge your car will be generated by Fossil Fuel, no matter what the value of the Grid CO2 emissions.
Unfortunately your logic around purchasing green electricity from a supplier may also be flawed.
All it may do, is make everyone else's electricity that little bit less green.
Reduction in usage is the greenest option.
I think this is a reasonable question but may be making some assumptions unnecessarily.
If you are using a whole day's solar production to charge your vehicle, and then running your house off mixed grid, then what would the benefit be? This would be a fruitless trade-off.
I think, though, you don't have to use the whole day's solar power. In broad terms, if you produce 25kWh per day, and need 15 for your home, there's nothing to say you have to use more than the last 10kWh for your vehicle. If you average 21 miles of driving per day, and your vehicle averages 3 kWh, then you only used 7kWh, and the additional 3kWh will still get you more full than you started that day. Just remember, you don't have to charge everything to 100%.
And for the sake of discussion, even if you drove 42 miles per day, and your 100% charge dwindled more each day even with 10kWh replacement, you could still have recharged for nearly 3 weeks (240 mile battery), before going to pay for a grid full charge top off. By managing your usage, you CAN offload demand of the grid and indeed reduce carbon footprint.
Regarding making the grid dirtier, that may be a short term response, but the market will see that people will want to buy renewable power directly, or else they will install solar and stop paying. If I'm a corporation I would want to offer renewable power to customers, rather than lose said customers from the grid.
@@jamesl1332The suggestion in the video was to select Green energy if you don't have solar panels. I think this may be questionable.
Yes, it is good to signal to Electricity Suppliers that Green is good, but most consumers think price is better.
Instead of installing battery storage in your home how about buying a second hand Nissan LEAF and not using it as a car.
The LEAF can put power back into your house and the second hand price is about 15,000 euros. But there is zero installation. You buy the car second hand and it works. Your house will need some sort of home intergration system, but the battery part doesn't need installing.
And if you have a power cut for a month or more then your home battery is on wheels and you can transport your electricity to yourself in extreme power cuts.