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Power EV from solar before powerwall/other-circuits/grid?
- Thread starter nanchux
- Start date
No. Solar inverters are AC coupled, and all loads are in parallel. You cannot direct the solar output to one device.
Short answer is "no but you can get close."
You'll probably be interested in this thread if you have a Powerwall system and your EV is a Tesla.
teslamotorsclub.com
If your entire ecosystem is Enphase (Enphase IQ8 + Encharge + Enphase EVSE + Enphase System Controller) ... then you'll want to read this whitepaper. Your installer is able to configure the Enphase system controller to have their EVSE charge with excess solar that isn't used by the home. But as far as I can tell, the home cannot be told to pull from the grid while the EVSE charges with the maximum solar generation.
My understanding from Enphase is that any brand BEV could work in this configuration to charge with excess solar - GM, Tesla, Nissan, Audi, etc. But the bi-directional EVSE technology for V2G and V2H applies to Nissan Leaf's at this time.
I hope @sunwarriors can get his Encharge system mated with a Bi-Directional BEV and tell us how cool this is heh.
PS... I believe it is also against NEC code to land the EVSE breaker on the same busbar / generation panel as your Enphase Combiner.
You'll probably be interested in this thread if you have a Powerwall system and your EV is a Tesla.
Tesla to add the ability to Charge EV with excess solar
Not sure if this is an Energy topic or EV topic, but I’m excited to try this. https://www.teslarati.com/tesla-charge-on-excess-solar-powerwall/ I know some people had luck with ChargeHQ, but I didn’t. Clean EV charging here we come.
teslamotorsclub.com
If your entire ecosystem is Enphase (Enphase IQ8 + Encharge + Enphase EVSE + Enphase System Controller) ... then you'll want to read this whitepaper. Your installer is able to configure the Enphase system controller to have their EVSE charge with excess solar that isn't used by the home. But as far as I can tell, the home cannot be told to pull from the grid while the EVSE charges with the maximum solar generation.
My understanding from Enphase is that any brand BEV could work in this configuration to charge with excess solar - GM, Tesla, Nissan, Audi, etc. But the bi-directional EVSE technology for V2G and V2H applies to Nissan Leaf's at this time.
I hope @sunwarriors can get his Encharge system mated with a Bi-Directional BEV and tell us how cool this is heh.
PS... I believe it is also against NEC code to land the EVSE breaker on the same busbar / generation panel as your Enphase Combiner.
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I can see the use case if you're using a EV in a V2H configuration to get around peak pricing.
For example, my Powerwalls are currently set up to maximize how quickly they charge. My goal is not to be self-powered... rather my goal is to ensure I can get from 3pm to 11pm without taking energy from the grid (thanks to PG&E and EV2-A). So from 9am to 3pm if the Powerwall SOC is less than 100%, they charge with the maximum amount coming from the solar panels. At this off-peak time, home loads are driven by energy coming from the grid.
So, if a bi-directional EVSE were set up and a homeowner wanted to bank maximum energy as fast as possible to do as much VPP as possible, they'd want the same thing where the EV charges first regardless of what is happening in the home.
My other dream was to land a bi-directional EVSE breaker on my solar generation panel. If the BEV could be configured to where it thought it was exporting energy to power a home load, there's a chance the output 240v AC from the BEV would appear as solar generation to the Tesla system. This could allow you to inject energy into a system much like a gas generator would have... but I've learned this is just a bad idea all around hah.
Is EV2-A from 3pm to 11pm? I thought it was 4pm to 9pm. I'm on EV1-A and Peak is 2pm to 9pm. Do you have a Partial Peak at all?
I'm better off charging EV during Off Peak and sending solar to grid during Partial Peak than using solar to charge EV
Lol my bad, EV2-A goes through midnight... this is why @Redhill_qik's ability to read is so valuable.
I agree, charging a BEV or Tesla Powerwalls after 3pm with this rate plan would be a bad idea. But if I can divert some solar-generated kWh into the batteries in the daytime before 3pm instead of into my home loads, I come out a head a little bit.
Also, what's sad about that above chart is that you could easily infer that only EV charging is hit with the rates. My neighbor said PG&E told them to "avoid or limit EV charging from 3pm to whenever" to avoid getting hit with the expensive rates. But the problem is all home loads get hit with the expensive rates. So when they got their new electricity bill having run ACs during the shoulder and peak times, they just about crapped their pants. They said it cost more to have a BEV with EV2-A than when the had E-TOU-C and paid for gasoline hah.
ok, you do have Partial Peak from 3 to 4 and 9 to midnight
I still don't see the use case for charging EV on solar when you can charge at midnight to sunup at 26 cents. The "value" of the solar is only $26 cents until 3pm whether you charge the EV or power the house. Its a wash. But you definitely don't want to charge the EV after 3pm.
I still don't see the use case for charging EV on solar when you can charge at midnight to sunup at 26 cents. The "value" of the solar is only $26 cents until 3pm whether you charge the EV or power the house. Its a wash. But you definitely don't want to charge the EV after 3pm.
Maybe OP is trying to set up an EV charging microgrid of sorts that never gets reported under NEM 3.0 hehe.
CrazyRabbit
Active Member
Someone should make a evse that monitors solar output with a neurio and controls the charge rate.
It's more valuable to measure the grid connection or get the data stream from a SmartMeter and redirect grid exports to EV charging.
Emporia EV Charger claims to have this feature if you:
Yeah I don't know why every smart EVSE seems to only work with "excess solar" by first metering what is going to the grid before deciding to charge the vehicle. There's no system that just sets the EVSE to charge at the gross production of the rooftop solar.
Here's the SolarEdge solution. Like Enphase's whitepaper and Tesla (what we think it'll do if it mimics ChargeHQ), it requires a consumption CT to measure what the home is taking, before configuring the EVSE to charge with the excess.
And as Miimura points out, the emporia system also uses a site meter to charge the EV at whatever energy would otherwise be backfeeding the grid. You cannot configure the Emporia smart EVSE to charge at the rate of the gross solar generation.
Maybe it's some form of bus protection to avoid the situation of the solar generating at peak while simultaneously drawing max energy from the grid to power the home?
Nope, it's as I said in the second post, you cannot direct all solar to anything. There is no way to do gross production charging in an AC coupled system that has other loads.
aesculus
Still Trying to Figure This All Out
I still don't understand why they have not created a "new home" architecture with a DC bus. In the old days GE would have been on this.
You can do this very easily.
You need a charger called a "Zappi" made by a company called "MyEnergi".
The Zappi monitors the grid and rather than let any electricity export it dumps it in the car. 2 kW surplus PV? You are charging at 2 kW. 7 kW surplus PV and you are charging at 7 kW. A cloud comes over and the Zappi adjusts. You can also set it up to allow the surplus to go to the powerwall first, or charge the car first and let the powerwall grab the surplus after the car is full or has been unplugged.
They are very popular in the UK, certain parts of Europe and Australia. I have not heard of one in the USA. I know you have a different voltage in the USA, but don't know if that is an issue? They do make both single phase and three phase models. It would be worth checking out as it is exactly what you are looking for and a great bit of kit.
www.myenergi.com
You need a charger called a "Zappi" made by a company called "MyEnergi".
The Zappi monitors the grid and rather than let any electricity export it dumps it in the car. 2 kW surplus PV? You are charging at 2 kW. 7 kW surplus PV and you are charging at 7 kW. A cloud comes over and the Zappi adjusts. You can also set it up to allow the surplus to go to the powerwall first, or charge the car first and let the powerwall grab the surplus after the car is full or has been unplugged.
They are very popular in the UK, certain parts of Europe and Australia. I have not heard of one in the USA. I know you have a different voltage in the USA, but don't know if that is an issue? They do make both single phase and three phase models. It would be worth checking out as it is exactly what you are looking for and a great bit of kit.
Renewable energy products making eco energy easy | myenergi
myenergi is an award-winning British designer and manufacturer of renewable energy products that increase the self-consumption of green energy.
www.myenergi.com
CrazyRabbit
Active Member
We aren’t talking about every single electron, just the same amount of energy going to car!
But what works for me is to break out a sharpie and mark the path on the wires so the electrons know where to go!
My idea was to see how close I can get to cut my reliance on the grid without (or with minimal) batteries. Charging my EV seems more important than running an appliance. WFH give me some flexibility to charge exclusively from solar during the daytime on 1 or 2 days a week. Plus one or both days of the weekend too I could charge my EVs. I will eventually get batteries but it seems too expensive right now. I wanted to see if I can go with minimal batteries for another 5 years and let the tech go down in price a bit more. During these 5 years I was calculating what is the minimum battery I need to sustain the lighting/heating when solar is not generating electricity.
you need to think cost, i.e., get the most out of your solar against rates versus charging EV
I don't see the purpose/reason for this. Is OP even going to be grandfathered in for NEM2.0 at this point? (meaning, have you already submitted your application and has it been approved by your utility?).
I don't see a reason to power your EV first before everything else because worst case, your EV can yse a public charger. For some EV owners, there's free charging as well for 3 years. If you need to wash dishes or wash/dry clothes, you can force yourself to do it only while sunny, but if you have a week of storms, that means no clean clothes or dishes.
Powering the EV after everything else means you also cut reliance on the grid as you can charge the EV during days of excess solar. I do that now already and just slow charge the EV over days if needed. This is very easy as you WFH or if you don't drive much.
If you are trying to not rely on the grid, then having a generator, a large solar system with batteries is the current best option still I think. Get/use the Ford F150 home power option if you can afford it for V2H, get batteries now if you don't want to tap the grid, but I still disagree that batteries will get massively cheaper vs. the battery delayers here. I think Tesla has raised prices for their PWs since earlier days and labor only goes up in price or the installers will move to other states if they don't make $$.
With enough solar panels and batteries, you can cut reliance from the grid pretty consistently around this time til winter comes back already (if in So Cal).
To avoid the grid, you really need enough batteries to consistently cover evenings every night so a small battery system is not going to cut it (for a regular sized CA home). You can self install a DIY battery solution if cost was a huge concern, but you get the usual DIY problems/support. For most people, I just suggest cut spending somewhere else if they really want to have batteries.
I don't see a reason to power your EV first before everything else because worst case, your EV can yse a public charger. For some EV owners, there's free charging as well for 3 years. If you need to wash dishes or wash/dry clothes, you can force yourself to do it only while sunny, but if you have a week of storms, that means no clean clothes or dishes.
Powering the EV after everything else means you also cut reliance on the grid as you can charge the EV during days of excess solar. I do that now already and just slow charge the EV over days if needed. This is very easy as you WFH or if you don't drive much.
If you are trying to not rely on the grid, then having a generator, a large solar system with batteries is the current best option still I think. Get/use the Ford F150 home power option if you can afford it for V2H, get batteries now if you don't want to tap the grid, but I still disagree that batteries will get massively cheaper vs. the battery delayers here. I think Tesla has raised prices for their PWs since earlier days and labor only goes up in price or the installers will move to other states if they don't make $$.
With enough solar panels and batteries, you can cut reliance from the grid pretty consistently around this time til winter comes back already (if in So Cal).
To avoid the grid, you really need enough batteries to consistently cover evenings every night so a small battery system is not going to cut it (for a regular sized CA home). You can self install a DIY battery solution if cost was a huge concern, but you get the usual DIY problems/support. For most people, I just suggest cut spending somewhere else if they really want to have batteries.
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