PG&E High NEM Charges

[rp1a]

Relatively new at this. We have a solar roof that was turned on at the start of 2021. Production has been much lower than expected. After four months, we have offset about 50% of our usage. For the time period, this has resulted in a reduction of a portion of our monthly electric bills, where we pay for generation and delivery. The reduction in the bill is a bit less than 50%.

However, we are also accumulating substantial NEM true-up charges at the same time. These true-up charges add up to more than the savings on our monthly bills. Overall, we are paying more for electricity (monthly + true-up) with our partial solar offset than without it.

We are in northern California, with PG&E.

Any suggestions will be appreciated.

 

[albertm3]

I think you need to back up a little bit, and not looking at the dollar amount first.
I'm in norcal bayarea, I'm getting between 5-6.8kWh per kW in my system, it average around 5.8kWh per kW. My system is 5.44kW * 5.8kWh = 31kWh per day. Using that you should be able to tell your average production per day is.

1. Are you getting the expected output from your system first?
2. When you size your system, what is the percentage to offset your electricity cost?

If you only doing 100%, then you will get some true-up at the end. Because TOU is more expensive than Tier rate. Around 20-25% more. To offset that pricing difference, either you produce 20-25% than what you use. Or you have a PW to offset the peak-time rate.

I totally understanding your math. You're trying to compare dollar amount cost with and without solar. But to answer your question, you need to starting from the production number and your system sizing.

If this is a system sizing problem (Sizing too small), then nothing you can do about it.
If this is a production problem then you might able to get some help from this forum to get an idea what is the problem. If this is a wiring problem, then you can contact Tesla.

Good Luck

 

[Ampster]

that is flat out wrong. Need to call them.

Some CCA (Community Choice Aggregation) providers have gone to a monthly charge basis to avoid the shock at True Up. This may be an example of that. Those charges are only for the CCA (Generation) portion of the bill not for the PB&E (Distribution) portion of the bill. .

 

[Ampster]

Because TOU is more expensive than Tier rate. Around 20-25% more.

That may be true for some users but it really depends on the consumption patters. I have been on TOU rates for ten years with solar and historically have consumed more than I generate and until recently always had a negative dollar bill. The only reason I now pay a small amount is the Non Bypassable Charges. I still consume more than I generate, but the NBCs offset my negative dollar credit.

 

[h2ofun]

That may be true for some users but it really depends on the consumption patters. I have been on TOU rates for ten years with solar and historically have consumed more than I generate and until recently always had a negative dollar bill. The only reason I now pay a small amount is the Non Bypassable Charges. I still consume more than I generate, but the NBCs offset my negative dollar credit.

Since TOU's vary, to blanket say they are more expensive, well, ...

 

[SaveOurPlanet]

After I got PTO from PG&E at end of March this year, I called Peninsula Clean Energy (CCA in the SF Bay Area) and asked about NEM2 since I've been on ECO100 for years and not knowing who is going to do true-up. They told me that PG&E will bill me monthly on delivery charge (NBC and that other $10.00 minimum charge I think) and I have to pay that monthly to PG&E. Peninsula Clean Energy will start their true-up clock every April, and it will be a running tab but I will have to pay month to month if it is a debit, it will roll over to the next month if it is a credit. This will go on until end of the annual true-up cycle then I will get a check if credit balance if over $100.00 otherwise it will be a rolling credit into the next true-up cycle starting April. So if I have started PTO in January and with low solar production I would most likely have to pay up every month until most likely March or April then I would start getting credit. Unless you have PW I think EV2-A is not as good as TOU-C or D as you have those shoulder rates.

 

[getakey]

The OP posted these numbers"

"Rough numbers -
No solar - Jan-April, 2020, usage 4400 kWh, charges total $700.
With solar - Jan-April, 2021, usage 2300 kWh, charges total $800 (= $250 on our monthly bills, and $550 true-up charges)."

That would mean his electrical charges went up with Solar. Even if undersized, that cannot be right. Even if on a CCA, this cannot be right

PG&E can make billing errors. They did with me when I got the PWs installed. They completely stopped crediting me for solar generation.

 

[Ampster]

Since TOU's vary,

But even if they vary, the opportunity to leverage them is all about optimizing revenue and reducing costs. That can be effective if loads can be shifted.

 

[Ampster]

Unless you have PW I think EV2-A is not as good as TOU-C or D as you have those shoulder rates.

I would tend to agree with you for most people because of the shoulder rates. EVs and Powerwall users can leverage TOU rates by shifting loads. A powerwall is the ultimate load shifting tool because it can allow revenue to be optimized by powering the home loads during peak time which allows all of the production to get credited at maximum rates. The Powerwall is charged from solar at lower rates thus shifting peak consumption to times when rates are lower.

 

[Ampster]

That may be true for some users but it really depends on the consumption patters.

I intended to type patterns above. As I think about it more the other thing that I should mention is a TOU rate does not have tiers. Penalty tiers can be more expensive than the highest TOU rates. So the blanket statement that TOU is more expensive has enough exceptions to make it a subjective statement that only applies in certain cases.

 

[holeydonut]

I would tend to agree with you for most people because of the shoulder rates. EVs and Powerwall users can leverage TOU rates by shifting loads. A powerwall is the ultimate load shifting tool because it can allow revenue to be optimized by powering the home loads during peak time which allows all of the production to get credited at maximum rates. The Powerwall is charged from solar at lower rates thus shifting peak consumption to times when rates are lower.

I can't stress this enough - this element of ESS really helps to bolster their case on "ROI" over the life. While PG&E can always say it costs them $0 to just delay doing the dishes until midnight, there's an implied benefit in my mind of doing the dishes at 7 and putting dry dishes away at 10.

Even with a partial home backup solution with one battery, this can be all it takes to shift energy consumption from the PoCo out of peak time. The key is to get an installer that knows how to put in a partial home backup system, but be able to meter non-backup loads so clean energy can be pushed upstream when the utility is operational. Easier said than done, but to me it makes ESS a no brainer if you find the right installer.

Naturally if the utility goes offline, then the one battery has no choice but to power a small set of loads. But that TOU shifting benefit will really help that single battery pay back over the coming decade.

 

[albertm3]

I can't stress this enough - this element of ESS really helps to bolster their case on "ROI" over the life. While PG&E can always say it costs them $0 to just delay doing the dishes until midnight, there's an implied benefit in my mind of doing the dishes at 7 and putting dry dishes away at 10.

Even with a partial home backup solution with one battery, this can be all it takes to shift energy consumption from the PoCo out of peak time. The key is to get an installer that knows how to put in a partial home backup system, but be able to meter non-backup loads so clean energy can be pushed upstream when the utility is operational. Easier said than done, but to me it makes ESS a no brainer if you find the right installer.

Naturally if the utility goes offline, then the one battery has no choice but to power a small set of loads. But that TOU shifting benefit will really help that single battery pay back over the coming decade.

It depends on the area you live. In CA, NEM2 has peak and non-peak rate. You have two way to offset the peak-rate. 1. get a battery system, store the electricity during non-peak (Daytime), and use it in peak (after sunset). The different is around 25% more for peak.

Putting some number in it, you will know ESS has a bad ROI. For $0.30 per kWh in PG&E in CA, 25% of that $0.30 is 7.5 cents you saved. Powerwall is around 10k. To break even, you need to use 133,333kWh. It means you need to use around 13,333kWh per year using 10 years warranty period. I use less than half of that per year.

The second way to offset the peak-rate difference is over produce by about 20-25%. Use the over produced credit to offset the peak-rate. For 8.16kW system, 20% more is only around $3,500. If you don't use much electricity using only 4kW system, the cost to get 25% is less than $2000.

That's a low better than paying 10k for powerwall.

This only apply if your area have net-metering, and you don't have a very big system. Of course if they change the rate, and how they calculate credit, it will change the end result.

IMO, I will oversize the system, and possible add battery later. One more thing, powerwall only have 10 years warranty, 25% more panel have 20-25 years warranty. I will wait at least powerwall cover the warranty to match the panel.

Again, this only work for my case, others might not be the same.

 

[holeydonut]

It depends on the area you live. In CA, NEM2 has peak and non-peak rate. You have two way to offset the peak-rate. 1. get a battery system, store the electricity during non-peak (Daytime), and use it in peak (after sunset). The different is around 25% more for peak.

Putting some number in it, you will know ESS has a bad ROI. For $0.30 per kWh in PG&E in CA, 25% of that $0.30 is 7.5 cents you saved. Powerwall is around 10k. To break even, you need to use 133,333kWh. It means you need to use around 13,333kWh per year using 10 years warranty period. I use less than half of that per year.

The second way to offset the peak-rate difference is over produce by about 20-25%. Use the over produced credit to offset the peak-rate. For 8.16kW system, 20% more is only around $3,500. If you don't use much electricity using only 4kW system, the cost to get 25% is less than $2000.

That's a low better than paying 10k for powerwall.

This only apply if your area have net-metering, and you don't have a very big system. Of course if they change the rate, and how they calculate credit, it will change the end result.

IMO, I will oversize the system, and possible add battery later. One more thing, powerwall only have 10 years warranty, 25% more panel have 20-25 years warranty. I will wait at least powerwall cover the warranty to match the panel.

Again, this only work for my case, others might not be the same.

PG&E was pretty aggressive in enforcing a 110% size limit on my PV array. For me, this didn't matter much, since my roof is restrained from many more panels. But, I did lose 1 panel from my theoretical "maximum that will fit" because PG&E wouldn't allow it or else I'd be like 112% of my previous year usage. I tried to tell PG&E that I was planning on buying an EV (which is true; I'm trying to get a HPWC installed now), but they didn't care. Rejected.

And the 25% variance between E-TOU-C peak/off-peak rates is what you see today. How much do you want to bet that in a few years after PG&E transitions everybody (who isn't medical baseline or low income) to E-TOU-C... that they will then jack up the ever living hell on the peak time rates and shift peak time to be like 5pm to midnight?

BTW, I got stuck on EV2-A, which has like a 150% variance between peak and off-peak. So yeah, ESS is a no-brainer for people in my situation. I never want to look at the clock and go "what does my energy cost right now? should I start my electric oven? oh no my AC is running and it's 5pm!!!". With batteries, it's just "turn the bastard on because who the eff cares."

But I do agree, for people in states closer to 1:1 net metering (regardless of time of use) and the ability to install monster solar arrays... just put more solar instead of buying batteries. Just remember that the utilities are going to fight as hard as they to be allowed to charge you a fee for the privilege of banking solar energy...

 

[h2ofun]

PG&E was pretty aggressive in enforcing a 110% size limit on my PV array. For me, this didn't matter much, since my roof is restrained from many more panels. But, I did lose 1 panel from my theoretical "maximum that will fit" because PG&E wouldn't allow it or else I'd be like 112% of my previous year usage. I tried to tell PG&E that I was planning on buying an EV (which is true; I'm trying to get a HPWC installed now), but they didn't care. Rejected.

And the 25% variance between E-TOU-C peak/off-peak rates is what you see today. How much do you want to bet that in a few years after PG&E transitions everybody (who isn't medical baseline or low income) to E-TOU-C... that they will then jack up the ever living hell on the peak time rates and shift peak time to be like 5pm to midnight?

BTW, I got stuck on EV2-A, which has like a 150% variance between peak and off-peak. So yeah, ESS is a no-brainer for people in my situation. I never want to look at the clock and go "what does my energy cost right now? should I start my electric oven? oh no my AC is running and it's 5pm!!!". With batteries, it's just "turn the bastard on because who the eff cares."

But I do agree, for people in states closer to 1:1 net metering (regardless of time of use) and the ability to install monster solar arrays... just put more solar instead of buying batteries. Just remember that the utilities are going to fight as hard as they to be allowed to charge you a fee for the privilege of banking solar energy...

I maybe finding out real quick, if I go forward with more solar, what the limits are in size. If the criteria is what one has pulled from PGE, with my existing solar, I have used MUCH less from PGE than if I had no solar. And now with batteries, even less. I am just hoping that the last 3 years can be used, since 1.5 year ago I used TONS. Will see what process the installer can use. If they cannot get approved, oh well, I save a lot of money,

 

[holeydonut]

I maybe finding out real quick, if I go forward with more solar, what the limits are in size. If the criteria is what one has pulled from PGE, with my existing solar, I have used MUCH less from PGE than if I had no solar. And now with batteries, even less. I am just hoping that the last 3 years can be used, since 1.5 year ago I used TONS. Will see what process the installer can use. If they cannot get approved, oh well, I save a lot of money,

I think all you need to do is point at a few years ago when you used a ton and PG&E will not be able to argue that you actually used that amount.

The house I bought was an empty nester house and I just don't have history of my own use to warrant more than an 8 kWp (DC) array. But if I had it my way I'd size up to like 10 to 12 kWp because as others said, solar is cheap.

Of course, I'd still want to install at least 1 battery (not that PG&E would have let me only do 1; because they're a$$holes). But the desire would still be there because we were losing power sporadically during the year we lived in this house.

 

[h2ofun]

I think all you need to do is point at a few years ago when you used a ton and PG&E will not be able to argue that you actually used that amount.

The house I bought was an empty nester house and I just don't have history of my own use to warrant more than an 8 kWp (DC) array. But if I had it my way I'd size up to like 10 to 12 kWp because as others said, solar is cheap.

Of course, I'd still want to install at least 1 battery (not that PG&E would have let me only do 1; because they're a$$holes). But the desire would still be there because we were losing power sporadically during the year we lived in this house.

I used in one 12 month period 40,000 KW's. It was nuts. I have 15KW of PV now, and may try to get approved another 15kw. If I do, I could put so EV cars in my garage

 

[Ampster]

1.5 year ago I used TONS. Will see what process the installer can use.

I suspect the installer will have to use numbers instead of adjectives. A few posts back I asked what your consumption was and have not heard back except that it was TONS.
EDIT; I see you subsequently posted 40,000 kWh. That is nuts.

 

[h2ofun]

I suspect the installer will have to use numbers instead of adjectives. A few posts back I asked what your consumption was and have not heard back except that it was TONS. Care to shre data?

This is what we submitted to PGE for my existing PV to justify

 

[MJ_CA_2019]

PG&E can make billing errors. They did with me when I got the PWs installed. They completely stopped crediting me for solar generation.

I also was not getting credit for any of my exports. On the black / white bill these are shown on a separate channel.
Make sure that you are getting credit for your exports. If you aren't it make take 2 months for the corrections. Should be fine due to annual true-up.

 

[Ampster]

This is what we submitted to PGE

My True Up (with battery load shifting) showed
Peak kWhs -775
Midpeak Khrs -1124
Offpeak 2371
My net consumption was 472 kWhrs but I had a dollar credit so I only paid NBCs. My total production on a 5.7kW system was 9kW so my total consumption was almost 10kWh and that is with two EVs. a HPWH, an electric clothes dryer and A/C.

 

[albertm3]

PG&E was pretty aggressive in enforcing a 110% size limit on my PV array. For me, this didn't matter much, since my roof is restrained from many more panels. But, I did lose 1 panel from my theoretical "maximum that will fit" because PG&E wouldn't allow it or else I'd be like 112% of my previous year usage. I tried to tell PG&E that I was planning on buying an EV (which is true; I'm trying to get a HPWC installed now), but they didn't care. Rejected.

And the 25% variance between E-TOU-C peak/off-peak rates is what you see today. How much do you want to bet that in a few years after PG&E transitions everybody (who isn't medical baseline or low income) to E-TOU-C... that they will then jack up the ever living hell on the peak time rates and shift peak time to be like 5pm to midnight?

BTW, I got stuck on EV2-A, which has like a 150% variance between peak and off-peak. So yeah, ESS is a no-brainer for people in my situation. I never want to look at the clock and go "what does my energy cost right now? should I start my electric oven? oh no my AC is running and it's 5pm!!!". With batteries, it's just "turn the bastard on because who the eff cares."

But I do agree, for people in states closer to 1:1 net metering (regardless of time of use) and the ability to install monster solar arrays... just put more solar instead of buying batteries. Just remember that the utilities are going to fight as hard as they to be allowed to charge you a fee for the privilege of banking solar energy...

Hi,

I want to share with people. I asked Tesla is there any limit on the size of the system from PG&E. I specifically asking the 120% rule that your have pointed out. The energy advisor told me, the have a team of people working with PG&E and communicated regarding the system sizing. She told me, they have people putting in 200% system of their last year usage, and it was fine. She told me if it go over 200%, it might be a problem. I didn't ask further why and how they can do it.

But what I see is Tesla have no problem put in a bigger system than your last year usage. This is my guess, they play around with the production number (reduce the output number) and "projected future increase" (increase this) to stay below that 110%. The rule is 110% of your last 12 months of usage AND PROJECTED FUTURE INCREASE.

They justify with 1 or 2 EV charging, and each EV takes 3000kWh. Then they bump up by 5000kWh without any problem.
At the end, the rule still be able to met. But reality is, I have a 160-170% system.

That's the difference between Tesla and other installer. They have PEOPLE know how to make it work.

The best thing to do is to ask Tesla what is the biggest system that you can put in. They would be able to tell you. Of course, my system is small compare to most of the people. Therefore, even I get 160% that's still less than 6kW system. May be from PGE point of view, that's below the radar.

One more thing regarding estimated production number, that can be easily saying there's tree and shading problem. Then later the tree was cut. Honestly, for some reason right after I finished install, my neighbor decided to cut down their big tree. One day, I came back home, the tree was gone. I got 10% more in production. So far my production is way above my expectation. I guess that's a good thing.