Bay Area PGE rate plan for EV + Solar panel

[wwu123]

wanted to bump this thread.
PGE introduced new E-TOU-D plan and according to them i would save more if i switch from EV-2A to E-TOU-D. its not that i trust PGE. Has anyone done analysis & compared prices?
Here is pricing for each reate: https://www.pge.com/pge_global/comm...-work/Residential-Rates-Plan-Pricing-2020.pdf
View attachment 622079

$30 difference is about 20-25% of your annual bill, which seems like a big % difference. But you have both large generation (as indicated by the big negative summer months) and large consumption (as indicated by the winter bills) in terms of kwh. While they won't likely change the TOU structure of either, any of their slight tweaking of the hourly per-kwh charge could easily swing that $30 difference in either direction.

Here's my dumb experience - with solar (no powerwalls) and EV's, I was around $120 net annual true-up, and I saw a slight advantage on the order of $20-30/yr of (now discontinued) EV-A over my grandfathered E-6, which had a few good years left before phasing out. Since EV-A was closing to new customers, I made the switch knowing I couldn't switch back to E-6. In short order, PG&E not only closed EV-A, they discontinued it, forcing everyone to EV2-A or E-TOU-A, then removed E-TOU-A, forcing those users to E-TOU-C or E-TOU-D. I lost out on $200-300/year, had I stayed on E-6, to try to save $20-30.

I believe they will keep messing with E-TOU-X variants until it is as disadvantageous as possible, especially with millions of E-1 customers being forced to them over the next year. While there is no guarantee of EV2-A, there are going to be far less customers on it for them to bother mucking with new varaiants such as EV3-A, EV4-A as frequently. So if I were you, I'd stay on EV2-A and hold out for something more substantial than $30/year savings, as there's no guarantee that E-TOU-D will be around a year from now. and a replacement is likely to not be in your favor...

 

[Ozarn]

Thanks for sharing your experience & i hear what you are saying. We all know that PG&E is not acting in our best interest etc to help us out.
Somehow however i did the math, E-TOU-D is working out in my favor compared to EV-2. I did lots of number crunching. Daily, Monthly & yearly
I like that E-TOU-D offers shorter peak time, from 5-8, instead of 4-9 & part peak 3-4, 9-12. This is the time when we use AC the most, even we try to cool off our house by 3pm.

One thing i could never figure out how PG&E calculates our cost, the numbers never add up.

 

[wwu123]

Not challenging that you've done the correct calculations and one is cheaper - at present. Just saying maybe don't chase small gains.

To put it more succinctly, in the last two years, this is rouglhy how my annual true-up would have increased under certain rate plans:
E-1 +14%
E-TOU-C +13%
EV2-A +16% (over the 1.5 years it's been around)
E-TOU-A +44% (comparing with its new spiritual successor E-TOU-D - despite the latter having a shorter peak period)

Not an exact apples-to-apples comparison as I'm comparing my consumption now vs 2 years ago, and like everyone behaviors have changed somewhat due to COVID. But basically they mucked with TOU so much, it's hardly TOU anymore - E-TOU-D is almost flat, plus a surcharge for summer afternoon A/C use.

 

[goldengate]

The original EVA rate was great for me. Annual true up was around $500 a year. The EV2-A rate completely messed that up, with a forecast true up of $1700 a year. I tried it for a month or two anyway and quickly saw it was going to be a disaster with running AC. I was also spending way too much time "managing" when we did everything... "No laundry until 7 am!!"... I switched back to the old E-1 rate and am very happy. It's much less expensive (I never leave tier 1) and I spend exactly zero time thinking about what time it is and if I can plug my car in.

If and when I buy a Powerwall it will make more sense for me to go back to EV2-A rate so I can consume (or sell) power from the wall during peak times. Until then, I hope to stay on E-1.

 

[AxlxA]

@goldengate the powerwalls do not supply the grid at all if you have solar+PW. Maybe on the SGIP set up.

With my solar+PW I'm basically getting off peak rates all the time because of the arbitrage of solar energy during off peak toward the peak hours. So now it's like $0.17/kwh without factoring in all the fees.

 

[miimura]

@goldengate the powerwalls do not supply the grid at all if you have solar+PW. Maybe on the SGIP set up.

With my solar+PW I'm basically getting off peak rates all the time because of the arbitrage of solar energy during off peak toward the peak hours. So now it's like $0.17/kwh without factoring in all the fees.

You probably know this but didn't say it clearly. With Powerwalls, any solar that you do generate during Peak hours can go to the grid to earn NEM credits while the batteries power your house. After the sun goes down, the batteries can continue to power the house and allow you to avoid paying the high Peak period price. How completely you can avoid paying Part-Peak and Peak prices on EV2 depends on how much battery and how much solar you have. In my case, my Winter solar generation is too low and I can't make it through the Peak period on battery, so a lot of my true-up cost comes from that Winter Peak usage.

 

[goldengate]

I was thinking if I got a powerwall I could capture energy during the nonpeak hours and sell it back at peak.... is that not the case?
In any event, leaving time of use rates feels like going back in time and I know this is temporary as everyone will be on them at some point soon, but I have to say I love not worrying about what time it is and knowing that my electricity is about 22 cents per kWh.

 

[miimura]

I was thinking if I got a powerwall I could capture energy during the nonpeak hours and sell it back at peak.... is that not the case?
In any event, leaving time of use rates feels like going back in time and I know this is temporary as everyone will be on them at some point soon, but I have to say I love not worrying about what time it is and knowing that my electricity is about 22 cents per kWh.

You can use the Powerwall to avoid billable Peak usage. However, you cannot export battery energy during Peak to earn excess NEM credits. You can only export your real-time solar generation during Peak while the batteries support your household loads. This is the effect of Tesla software regardless of the utility rules which may or may not allow more than that.

 

[tivoboy]

Ugh.. PGE is the worst.. they are removing Tiered rates starting in June. we often don't use that much electricity, but even with the tiers now being 20% higher than A YEAR AGO it was better than nearly any TOU more based on summer AC and some evening HEAT use vs. the EV charging (which often gets done for free in town, regardless). I almost feel like we're back in the late 1990's early 2000's and trying to figure out which cell phone plans is best for you/family, etc. I gotta just move on to solar and battery backup and be done with them.

 

[Ampster]

Ugh.. PGE is the worst.. they are removing Tiered rates starting in June.....

It is not just PG&E, the other IOUs are doing the same because the regulators are forcing the issue.
I have been on TOU rates for eight years with solar and two EVs. I did have some access to free charging in the town that I lived in a few years ago but in the long term you just can't beat that $0.15per kWh rate for EV charging. I do agree the economics of solar and batteries as the long term hedge against increased rates.

 

[loanchau2k]

Hi, please help me to understand about solar. Assuming I buy enough panels, send electricity to PG&E grid, say 10,000kwh per year. As long I use under or equal to 10,000kwh per year, I should not worry about peak or non-peak usage, right? I really don't understand the conversation Solar +PW and use PW during peak. This seems to me that the solar does not produce enough energy that you guys use yearly?

Thx guys,

 

[wws]

Hi, please help me to understand about solar. Assuming I buy enough panels, send electricity to PG&E grid, say 10,000kwh per year. As long I use under or equal to 10,000kwh per year, I should not worry about peak or non-peak usage, right? I really don't understand the conversation Solar +PW and use PW during peak. This seems to me that the solar does not produce enough energy that you guys use yearly?

Thx guys,

The annual true-up is done on a $$$ basis, not per kWh. So more power needs to be generated before 3 pm to offset the more expensive power used between after the sun goes down and midnight. Note that there is also a $10/month minimum charge for grid connection regardless.

 

[miimura]

Hi, please help me to understand about solar. Assuming I buy enough panels, send electricity to PG&E grid, say 10,000kwh per year. As long I use under or equal to 10,000kwh per year, I should not worry about peak or non-peak usage, right? I really don't understand the conversation Solar +PW and use PW during peak. This seems to me that the solar does not produce enough energy that you guys use yearly?

Thx guys,

It really depends on your usage pattern. If you have significant unavoidable consumption between 4pm-9pm, you may want to use a Rate plan that doesn't have big differences in price between Peak and Off-Peak, like TOU-C. When you have nearly equal total annual kWh generation and consumption, there is a chance that rate plans like EV2 with a large difference between Peak and Off-Peak can cost you more money. However, usage like Off-Peak EV charging will cost you more money while your solar will also earn more credits. It's all a balancing act that depends strongly on your usage pattern.

In my specific case, I have a small solar system and Powerwalls, so EV2 is clearly the right choice because I can have both low cost EV charging and avoid high priced household consumption during Peak.

 

[Cheburashka]

You can use the Powerwall to avoid billable Peak usage. However, you cannot export battery energy during Peak to earn excess NEM credits. You can only export your real-time solar generation during Peak while the batteries support your household loads. This is the effect of Tesla software regardless of the utility rules which may or may not allow more than that.

Really? I don't have a Powerwall, I have a LG Chem RESU10H, which is LG's ghetto PW equivalent, and that is exactly how it works. It charges off-peak and then dumps all that energy back into the grid during peak hours. The result is that I have a ton of credits at true-up.

I don't understand why a PW wouldn't work the same way.

 

[miimura]

Really? I don't have a Powerwall, I have a LG Chem RESU10H, which is LG's ghetto PW equivalent, and that is exactly how it works. It charges off-peak and then dumps all that energy back into the grid during peak hours. The result is that I have a ton of credits at true-up.

I don't understand why a PW wouldn't work the same way.

This is just how the software is set up to work. There are some places and some interconnection agreements that allow battery energy export and some that don't. It's simply easier for Tesla to have uniform operation that only allows battery energy to supply household loads. The limitation of only allowing charging from solar also allows as many people as possible to conform to the Federal Tax Credit requirement.

 

[Ampster]

I don't understand why a PW wouldn't work the same way.

Presumably the inverter that is connected to your LG battery can be programmed differently than Tesla has programmed the inverter in the Powerwall. What kind of inverter do you have?

 

[Cheburashka]

Presumably the inverter that is connected to your LG battery can be programmed differently than Tesla has programmed the inverter in the Powerwall. What kind of inverter do you have?

SolarEdge StorEdge 7600A-US. I believe that Tesla has used this same inverter as well on some installs.

 

[Ampster]

I believe that Tesla has used this same inverter as well on some installs.

My understanding is that the first version of the Powerwall used them and another brand. Powerwall 2 contained its own inverter. @miimura explained the programming differences. Are you taking the Federal Tax Credit for your battery system? If so, how are you documenting how often your batteries are charged from solar?

 

[Cheburashka]

My understanding is that the first version of the Powerwall used them and another brand. Powerwall 2 contained its own inverter. @miimura explained the programming differences. Are you taking the Federal Tax Credit for your battery system? If so, how are you documenting how often your batteries are charged from solar?

My battery is set to only charge from solar. It's also set to discharge to the grid during peak hours.

You mean the 30% tax credit? I did take it when I got the system installed.

 

[Ampster]

My battery is set to only charge from solar

Sorry for making the wrong assumption. I misunderstood your earlier comment that you charged off peak and interpreted that to mean from the grid.
I have a third party non Powerwall system as well. I have been tempted to tweak the programming but as I near my True Up I still have a credit that I am trying to burn off.