Rude awakening on solar EV charging

[Saksak]

I recently installed solar and I knew NEM 3.0 made solar less attractive for homeowners, but I didn’t know how bad it would be for EV owners.

Credits I earned by supplying excess solar to grid:

• May 22: $0.46 supplying 31.0kWh
• May 23: $0.37 supplying 48.4 kWh
• May 24: $0.23 supplying 36.3 kWh

Cost to charge my EV at night (the cheapest rates) for exactly the same amount of power sent to grid: $39.34 ($0.34 * 115.7 kWh). The utility company essentially bought my energy for $1 and sold it someone else for a minimum of $39 (utility companies are putting in place their own battery infrastructure).

I do have home batteries but that’s primarily for emergency power during power outages. I don’t want to be draining my home battery every night to charge my EV, especially since home batteries are much smaller than EV batteries.

This means the best strategy is to charge my EV with the excess solar power instead of sending it to the grid. However, I’m usually driving my car during the day, making this impossible.

NEM 3.0 is pretty bad. We earn a quarter or two of credits per day and need to spend 40x that amount to draw the same amount of power. What incentive is there to send power to the grid?

 

[BS8899]

I recently installed solar and I knew NEM 3.0 made solar less attractive for homeowners, but I didn’t know how bad it would be for EV owners.

Credits I earned by supplying excess solar to grid:

• May 22: $0.46 supplying 31.0kWh
• May 23: $0.37 supplying 48.4 kWh
• May 24: $0.23 supplying 36.3 kWh

Cost to charge my EV at night (the cheapest rates) for exactly the same amount of power sent to grid: $39.34 ($0.34 * 115.7 kWh). The utility company essentially bought my energy for $1 and sold it someone else for a minimum of $39 (utility companies are putting in place their own battery infrastructure).

I do have home batteries but that’s primarily for emergency power during power outages. I don’t want to be draining my home battery every night to charge my EV, especially since home batteries are much smaller than EV batteries.

This means the best strategy is to charge my EV with the excess solar power instead of sending it to the grid. However, I’m usually driving my car during the day, making this impossible.

NEM 3.0 is pretty bad. We earn a quarter or two of credits per day and need to spend 40x that amount to draw the same amount of power. What incentive is there to send power to the grid?

How much solar (Watts of panels) do you have and where is your home?
How much battery backup do you have?

 

[DeaneG]

I recently installed solar and I knew NEM 3.0 made solar less attractive for homeowners, but I didn’t know how bad it would be for EV owners.

Credits I earned by supplying excess solar to grid:

• May 22: $0.46 supplying 31.0kWh
• May 23: $0.37 supplying 48.4 kWh
• May 24: $0.23 supplying 36.3 kWh

Cost to charge my EV at night (the cheapest rates) for exactly the same amount of power sent to grid: $39.34 ($0.34 * 115.7 kWh). The utility company essentially bought my energy for $1 and sold it someone else for a minimum of $39 (utility companies are putting in place their own battery infrastructure).

I do have home batteries but that’s primarily for emergency power during power outages. I don’t want to be draining my home battery every night to charge my EV, especially since home batteries are much smaller than EV batteries.

This means the best strategy is to charge my EV with the excess solar power instead of sending it to the grid. However, I’m usually driving my car during the day, making this impossible.

NEM 3.0 is pretty bad. We earn a quarter or two of credits per day and need to spend 40x that amount to draw the same amount of power. What incentive is there to send power to the grid?

The only incentive takes place for one hour per day for two months in the fall, when you can sell your battery's worth of electricity for $2-3 per kWh.

I've also found that NEM3 pretty much kills the incentive to add solar, unless you can charge your EV with excess solar generation during the day.

Battery backup is nice to have though.

 

[Mr.Quindazzi]

Where are you?

 

[DeaneG]

Another issue with NEM3 - there is almost zero payback for adding panels that produce more electricity than you need. And you need a pretty substantial home battery (nearly a full summer's day consumption) to make the best use of a smaller number of panels.

Bottom line for me: the CPUC is trying to discourage rooftop solar unless heavily backed by batteries. Fair enough, as both of these functions can be done much more cheaply at grid scale.

 

[Saksak]

Where are you?

I’m in California where NEM 3.0 is in effect for three major utility companies: PG&E, SCE, and SDG&E for new solar installations since April 2025.

 

[scal_air]

Yeah, NEM 3 is the crown jewel of the power companies control over the "regulatory CPUC" .
Really not worthwhile unless you purchase enough batteries to zero out power use. Of course, that lengthens the time to recoup your initial outlay. Combine that with the new monthly fees, and you can't help but come to the conclusion that the power utilities want to maintain their monopoly.

It's the reason so many of us want V2H ASAP, to take advantage of the large capacity storage ability of our cars.

 

[BS8899]

Yeah, NEM 3 is the crown jewel of the power companies control over the "regulatory CPUC" .
Really not worthwhile unless you purchase enough batteries to zero out power use. Of course, that lengthens the time to recoup your initial outlay. Combine that with the new monthly fees, and you can't help but come to the conclusion that the power utilities want to maintain their monopoly.

It's the reason so many of us want V2H ASAP, to take advantage of the large capacity storage ability of our cars.

I agree with everything you said RE: NEM 3.

That said, has anyone sat down and do the economics of V2H, taking into account the additional charge/discharge cycles and short lifetime of the car batteries. I haven't done the math, but I am skeptical whether V2H is a good economical solution vs other alternatives (e.g., adding home storage batteries).

I'd love to see an end-to-end economic analysis of the different solutions.

 

[scal_air]

I agree with everything you said RE: NEM 3.

That said, has anyone sat down and do the economics of V2H, taking into account the additional charge/discharge cycles and short lifetime of the car batteries. I haven't done the math, but I am skeptical whether V2H is a good economical solution vs other alternatives (e.g., adding home storage batteries).

I'd love to see an end-to-end economic analysis of the different solutions.

I guess it depends on how many full discharge cycles the battery can undergo...
Here are some musings from our own forum

life of the battery | Lucid Owners - Lucid Motors Forum https://share.google/iGI1uKI0GLmnxpGmq

AI thinks Tesla powerwall are good for up to 5000 cycles (powerwall 2 - Nickel Manganese Cobalt) or 10,000 for powerwall 3 - Lithium Iron Phosphate.

The Air uses NMC chemistry, so maybe the comparison should be with second generation powerwalls? If that's the case, it seems favorable to me.

 

[BS8899]

I guess it depends on how many full discharge cycles the battery can undergo...
Here are some musings from our own forum

life of the battery | Lucid Owners - Lucid Motors Forum https://share.google/iGI1uKI0GLmnxpGmq

AI thinks Tesla powerwall are good for up to 5000 cycles (powerwall 2 - Nickel Manganese Cobalt) or 10,000 for powerwall 3 - Lithium Iron Phosphate.

The Air uses NMC chemistry, so maybe the comparison should be with second generation powerwalls? If that's the case, it seems favorable to me.

I'd suspect replacing a home storage battery is much simpler process and lower cost when compared to replacing a car battery. That was the basis of my question.

That said, at the rate EVs are depreciating, after 4-5 years of ownership, the whole EV, including the battery, might not be worth much.

At the risk of digressing:

> is true or not true that when most EV battery bank goes "bad", it is usually a handful of defective cells (vs the entire battery bank going bad). To the extent that these defective cells can be isolated/by-passed/replaced, does the economics work for owning/driving an EV like the Lucid for 10+ years?

 

[Northpointe]

I'd suspect replacing a home storage battery is much simpler process and lower cost when compared to replacing a car battery. That was the basis of my question.

That said, at the rate EVs are depreciating, after 4-5 years of ownership, the whole EV, including the battery, might not be worth much.

At the risk of digressing:

> is true or not true that when most EV battery bank goes "bad", it is usually a handful of defective cells (vs the entire battery bank going bad). To the extent that these defective cells can be isolated/by-passed/replaced, does the economics work for owning/driving an EV like the Lucid for 10+ years?

Things could look very different in 4-5 years. Imagine a world where changing a car battery is almost as simple as changing a battery on a cordless tool.

 

[BS8899]

Things could look very different in 4-5 years. Imagine a world where changing a car battery is almost as simple as changing a battery on a cordless tool.

I agree with you. China is taking the leadership position in EV innovation and manufacturing. Battery swapping is already there. Part of that is also driven by the fact that most Chinese residences don't have their own in-home charging capability.

It is sad to see that our current government policies are giant steps backward in terms of renewable energies, solar, wind, hydro, nuclear., etc.. We are living in the past!

 

[Northpointe]

It will ultimately happen here. The auto makers have all but acknowledged that. You won’t survive solely focusing on the US market utilizing outdated technology. We’ll just find ourselves trying to catch up with the rest of the world.

 

[nck]

Yeah, NEM 3 is the crown jewel of the power companies control over the "regulatory CPUC" .
Really not worthwhile unless you purchase enough batteries to zero out power use. Of course, that lengthens the time to recoup your initial outlay. Combine that with the new monthly fees, and you can't help but come to the conclusion that the power utilities want to maintain their monopoly.

It's the reason so many of us want V2H ASAP, to take advantage of the large capacity storage ability of our cars.

Agree, need V2H ASAP. Going to be a game changer for EVs. I might get a used one just for storage capacity

 

[nck]

I agree with everything you said RE: NEM 3.

That said, has anyone sat down and do the economics of V2H, taking into account the additional charge/discharge cycles and short lifetime of the car batteries. I haven't done the math, but I am skeptical whether V2H is a good economical solution vs other alternatives (e.g., adding home storage batteries).

I'd love to see an end-to-end economic analysis of the different solutions.

I didn't do the math but getting something like a used EV9 for storage is probably cheaper than getting a 100KWH Home Battery

 

[Dolphins4ever]

200 kWh Chevy Silverado new ~70k, add about $20k for gm ridiculously priced hardware and installation might be a touch more, but I am sure you could haggle $5k off the truck, so 90k all in vs Tesla powerwall would be at least $10k installed for 13.5kwh per, so way less than stationary battery and you get a truck!

The downside is it won’t pencil out in terms of payback because the tax incentives are gone, but the depreciation can help especially with the big year one break now in place.

 

[scal_air]

200 kWh Chevy Silverado new ~70k, add about $20k for gm ridiculously priced hardware and installation might be a touch more, but I am sure you could haggle $5k off the truck, so 90k all in vs Tesla powerwall would be at least $10k installed for 13.5kwh per, so way less than stationary battery and you get a truck!

The downside is it won’t pencil out in terms of payback because the tax incentives are gone, but the depreciation can help especially with the big year one break now in place.

Heck, buy a used Silverado and get that bonus of steep EV depreciation to make it even cheaper. But I'd buy an used air for half the capacity and half the price and enjoy the benefit of driving something I like...

 

[Pragmatic]

GM has V2H now, Lucid has promised it later this year.

 

[scal_air]

Right. Good point!

 

[martinjlm]

Things could look very different in 4-5 years. Imagine a world where changing a car battery is almost as simple as changing a battery on a cordless tool.

It will ultimately happen here. The auto makers have all but acknowledged that. You won’t survive solely focusing on the US market utilizing outdated technology. We’ll just find ourselves trying to catch up with the rest of the world.

I've actually consulted on the potential for battery swapping. It's highly unlikely to happen in the US. The issue is that for most EVs available in the US, the battery pack is a structural element of the vehicle. Like frame rails and engine cradles are structural elements of ICE cars. The structure is something you don't want to just play around with. Plus, every EV manufacturer takes a different approach to how the battery pack integrates into the structure so you would need to have an environment where every manufacturer has swapping infrastructure for their own vehicles or a 3rd party has the capability of quickly servicing multiple brands / makes of EV. Research the company "Better Place".

Better Place was an Israeli based battery swapping venture supported by several European OEMs including Renault for sure and possibly PSA. Didn't last long. Nio in China is by far the most successful approach to battery swapping, but as of my last look into this topic (3 or 4 years ago) they could only swap their own batteries in their own vehicles. VinFast was also looking at going that route, at least in their home market but I haven't confirmed that they actually went through with it.

For Europe and the US the growth of battery recycling and battery remanufacturing will likely evolve to a cost basis that swapping will not be able to approach. That is something that the OEMs doing business in the US are already supporting with their money.

Kim Java tour of battery recycling center