Home Vehicle Charging with lots of solar panels and net metering question.

[tearitupsports]

I'm not making it complex. . . I'm simply telling you all what's happening.

It's noon in SoCal. I know that I'm "receiving" 10-13 KW from my 41 solar panels.
I plug in my truck to charge, which according to the Ford app is pulling in 15.6 KW.
My power meter also says I'm pulling in roughly 15.6 KW from the grid. . .

Where does the 10-13 KW from my solar panels go. . . ? To the ground? To heat? Partially back to the grid?

You're trying to tell me that it goes to the main panel and thereby into the truck, but I'm saying if that was true then the meter would not be reading -15KW and the meter could not possibly equal the same value as what the truck is charging at. . .

Yes it's all one meter I should add. . .

If you use the m-professional app, it will tell you what is happening in real time. Just look at that.

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[K6CCC]

It's noon in SoCal. I know that I'm "receiving" 10-13 KW from my 41 solar panels.
I plug in my truck to charge, which according to the Ford app is pulling in 15.6 KW.
My power meter also says I'm pulling in roughly 15.6 KW from the grid. . .

You are likely forgetting about the rest of your house load, and I can almost guarantee you are not getting 13 KW from your 41 panels - unless they are all tracking the sun (VERY unusual for a home install).

Here's a test. First of all, turn off the truck charging, and then turn off the breaker for your solar. What is left is your house load - see what your meter shows. Next step is turn the solar back on and see what the meter shows. Presumably it will be a negative number since I assume your solar is generating more than your house load. Let's say that your house load is 2KW and when the solar is turned on (give it a minute) the meter shows -6KW. That means that your solar is producing 8 KW (2KW supplying the house and 6KW going to the utility). Now turn on the truck charging and confirm the charge rate to the truck, and what the utility meter shows. At that point, it will most likely become a positive number since the combined house load and the truck charging will be larger than the solar output.. So continuing to use the example numbers above, if the truck is drawing 11KW, the meter should be showing about 5KW.

 

[K6CCC]

Does everyone have some form of off peak power? I have solar panels but almost all of that goes back to the grid. I charge at night for less than half of what I get paid for what was produced.

I am on a Time Of Use rate. When I first got solar, the daytime vs nighttime rates made it far more to my advantage. I was forced onto a different TOU rate plan after five years that is FAR less to my advantage. The peak rate is from 1600 - 2100, during which time the solar is rapidly dropped off. The back yard tree that shades most of the panels in the late afternoon does not help either...

 

[SDSean]

"So continuing to use the example numbers above, if the truck is drawing 11KW, the meter should be showing about 5KW. "

This is exactly my point. . . .if I plug in the truck, the meter says it's pulling roughly 15KW from the grid, and the truck in turn says it's charging at roughly 15KW. If it happens to be daytime. . .I still have solar power in theory coming in, but apparently going no where. . .even if it was powering the rest of the house load (to your point most likely 2K or less), I would expect the meter to show a 13KW, not 15KW. . .I also wouldn't expect that me say turning on a microwave would show the meter at an additional pull of 1KW (i.e. 16KW), but it does. . .

And to your point even if it's not peak power. . . let say I'm only getting 6-8KW in from solar (very very common), why does the meter say it's pulling from the grid an amount that's not 15 minus 6-8?. . .

The behavior is consistent btw. . .

 

[Joe.....Montana]

If you have one meter it is just measuring the flow of electricity (in either direction)...I have 36 panels on my roof and instantaneous peak production (mid summer, mid day, no clouds) is around 10kW (just checked July 18, 2024)...I would start with verifying solar production and total household use as K6CCC stated.

 

[SDSean]

Yeah i mean I can take some pictures just to show what I'm talking about. . . I'll try tomorrow

 

[Adventureboy]

If you pair an Emporia EVSE with their energy monitor, it will automatically limit the charge rate to the excess solar being produced.

I have this - it works really well. The automatic adjustment is key here. Turn the switch on and the EVSE does the rest.

 

[Devereuxstreet]

I'm not making it complex. . . I'm simply telling you all what's happening.

It's noon in SoCal. I know that I'm "receiving" 10-13 KW from my 41 solar panels.
I plug in my truck to charge, which according to the Ford app is pulling in 15.6 KW.
My power meter also says I'm pulling in roughly 15.6 KW from the grid. . .

Where does the 10-13 KW from my solar panels go. . . ? To the ground? To heat? Partially back to the grid?

You're trying to tell me that it goes to the main panel and thereby into the truck, but I'm saying if that was true then the meter would not be reading -15KW and the meter could not possibly equal the same value as what the truck is charging at. . .

Yes it's all one meter I should add. . .

You may need to have your solar company come take a look and explain. There is no way the solar generated electricity is going to ground, or being turned into heat.

 

[RickLightning]

You may need to have your solar company come take a look and explain. There is no way the solar generated electricity is going to ground, or being turned into heat.

Right. Clearly the OP needs to gain a better understanding of how their solar system works, which has nothing to do with the truck.

 

[SDSean]

Right. Clearly the OP needs to gain a better understanding of how their solar system works, which has nothing to do with the truck.

I understand just fine, there's no need to get testy. I'm simply telling you all what my meter is saying, and trying to figure out why the math doesn't add up. I'll take some pictures and post back.

 

[RickLightning]

I understand just fine, there's no need to get testy. I'm simply telling you all what my meter is saying, and trying to figure out why the math doesn't add up. I'll take some pictures and post back.

Getting testy?

You seem to think that this has anything to do with the Lightning, when it clearly doesn't. You have a simple question to answer - when your usage is less than the power generated by the solar panels, where does the power go, and how can you see that? Or, when your usage is more than the solar is generating, why is the meter showing what one source (truck) is pulling?

Seems like a 1 minute call to your solar company would answer that question.

Also, your understanding of what the truck is pulling is off. FordPass shows you the NET to the truck. The charger is pulling more than that - divide the FP number by 0.93 to get the gross energy used.

 

[gbuydos]

I am guessing you are a LADWP customer, or maybe SCE, doesn't really matter. As the previous solar manager for the utility out there, we often explained this to our customers. Energy produced by your panels directly offsets the load being used in the house. Meaning that energy produced by your solar goes into the house first, then any excess either flows back to the grid or to your battery storage, if you have any. Your net meter from utility tracks all. It has reads for delivered, exported and net. After the sun goes down, your house is entirely powered by the grid or batteries till the sun rises the next morning. So if you plug the truck in while the sun is shining, part of the solar energy is charging your truck, if it is not enough, then the grid helps.

 

[gbuydos]

Also remember you solar panels do not produce heavy amp based power. A Lightening can be charging up to 80Amps, depending. A PV system may only be producing 35 amps. Check your PV breaker size and compare your EV charger breaker size. Also remember your utility meter is bidirectional and can feed energy both directions.

 

[SDSean]

Getting testy?

You seem to think that this has anything to do with the Lightning, when it clearly doesn't. You have a simple question to answer - when your usage is less than the power generated by the solar panels, where does the power go, and how can you see that? Or, when your usage is more than the solar is generating, why is the meter showing what one source (truck) is pulling?

Seems like a 1 minute call to your solar company would answer that question.

Also, your understanding of what the truck is pulling is off. FordPass shows you the NET to the truck. The charger is pulling more than that - divide the FP number by 0.93 to get the gross energy used.

I never once said it had anything to do with the Lightning. . . I asked the question in this forum b/c it was the easiest place to start.

To your point, I did call the solar company, and I didn't get an answer that made sense beyond, "I'm pulling from the grid when charging the truck" which I already knew. . .

Fair enough on net charging. . . that makes sense, but still that number is very very close to what my meter is reading as the charger is pulling, and again that's what's got me confused. . .

If I have 6KW that I'm pushing back to the grid from solar before I start charging according to my meter, and then I start charging and I'm now pulling 15KW from the grid according to the meter, and Ford Pass basically also reads the same amount (again yes we can adjust a bit for net). Assuming it didn't just suddenly get dark. . .I'm baffled by those meter numbers. In that scenario, there's roughly 5KW "missing". . . of course it's going to the main panel still. . . and some portion of that is the rest of the load in the house, but is the rest just getting pushed back to the grid and the meter doesn't show that (that seems reasonable)?

 

[SDSean]

Also remember you solar panels do not produce heavy amp based power. A Lightening can be charging up to 80Amps, depending. A PV system may only be producing 35 amps. Check your PV breaker size and compare your EV charger breaker size. Also remember your utility meter is bidirectional and can feed energy both directions.

Right right, I get that. . . but maybe that's more the essence of my question. . . can it feed energy in both directions at the same time. . . ?

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