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Choosing PG&E Rate Plan (Solar with Storage)
- Thread starter pgrovetom1
- Start date
I want to understand this a bit more. When I was on ETOU-C, my powerwall didn't discharge during peak in the winter. Is anyone's powerwall discharging in the winter that's using PG&E?
Current rates (ignoring baseline)
Summer peak: $0.48902
Summer off-peak: $0.42558
peak to off peak ratio: 115%
Winter peak: $0.39193
Winter off-peak: $0.37460
peak to off peak ratio: 104.6%
in this scenario, that means the powerwall would not be used during winter since the ratio is less than the 10% roundtrip efficiency, whereas in summer it would discharge between 4-9pm.
I am currently a net exporter so should I switch back to ETOU-C now or after true up? I am 8 months into my first cycle and I have 3800 kWh exported. And wouldn't being on ETOU-C mean I would likely increase my NBCs above the monthly minimum bill, since there would be 4 additional hours each day where I am pulling energy from the grid, whereas on EV2-A my powerwall covers my usage for 4 additional hours.
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RKCRLR
Active Member
I'm a net producer on EV2A using Time Based Control and my Powerwalls have always discharged during peak in the winter. I currently have my rates in the app set to reflect the PG&E Peak, Partial Peak, and Off Peak rates other than I've set the sell price to be $0.03/kWh lower than the actual rates to account for NBCs. So far I'm pretty happy with the results. The app does a decent job of balancing recharging the Powerwalls and home solar self-consumption to reduce the NBCs in the morning off-peak hours. I do wish the app would give priority during partial peak and peak hours to home solar self-consumption over sending all solar to the grid but I don't think there is much of a financial impact to that.
Yup EV2A discharges during peak in the winter, but what about ETOU-C peak in the winter? The ratio is less than the round trip efficiency of the powerwall.
I’m currently on the EV2A plan as well and I don’t expect to pay anything extra beyond the minimum monthly bill at true up since I have been charging my car mostly with solar, though it is getting more difficult now during the winter
RKCRLR
Active Member
I can't answer that since I haven't tried it. But if you really wanted to find out you could enter the rates in the app as if you were on ETOU-C and see what it does. But it sounds like you are better off on EV2A for your situation.
I use an app called PGE Toolkit that helps break it down. With two electric cars I use a lot of off peak so EV2-A makes more sense, but at my parents house where there is only solar and no EVs TOU-C was much better. I wish I could still sign up for EV-A.
Attachments
I took another 10% off the sell rates to reflect the charge/discharge inefficiencies of Powerwalls, as I wasn't confident Tesla priced the inefficiencies into their algorithm. My thinking was as long as it covered at least the NBCs, any additional ding didn't hurt.
Our charging shows the same behavior of covering us during peak always, and favors Powerwall charging first, and the switches to full solar later in the day. Like you the midpeak rate doesn't contribute much to use financially, so I haven't sweated details. If I did, I would just make peak run from noon to midnight.
All the best,
BG
in the context of that post,
MDC = Minimum Daily Charge
NBC = Non Bypassable Charges
What are "cumulative NBCs" and "annual MDCs"? I seem to be in transition/limbo 5 weeks after PTO, currently NEM2PS and transitioning to E-TOU-C. 5kW w/ 2 TESLA batteries.
The total of the Non-Bypassable Charges and Minimum Daily Charges at your annual true-up.
It looks like you are with PG&E, so you should read this sticky thread NEM-PS Annual True-Up Calculation [PG&E example]
You can qualify for SGIP under a medical baseline with multiple PSPS shutoffs and keep E-TOU-C. If you qualified for another reason like a well pump in a high fire area that has had multiple PSPS shutoffs, you have to be on EV2A.
dho112
Member
I’m finding this thread very interesting and useful!
I’m dizzied by the number crunching involved in finding the best fit of plan vs my usage. I’m on ETOU-C
I have all my friends with Teslas telling me I HAVE to get the EV2 plan, because you then charge your car at night off peak for the lowest rate. The thing is, none of them have battery/Solar.
My situation is I only charge my car during the day because I have a 9.6Kw solar battery system and our Tesla is 99% of the time a light daily driver so it’s essentially 100% powered by our solar. The batteries provide all the power we need from 4pm to the next day where they get fully charged by 10-11am and I’m on solar all day with plenty going back to the grid, even with car charging.
The rub for me getting an EV plan is that the off peak charge is horrendously high, and exactly when I MIGHT have to tap into the grid if I underproduce solar, while my nighttime off peak grid usage is always zero.
I’m constantly wondering if I’m doing it right…
I’m dizzied by the number crunching involved in finding the best fit of plan vs my usage. I’m on ETOU-C
I have all my friends with Teslas telling me I HAVE to get the EV2 plan, because you then charge your car at night off peak for the lowest rate. The thing is, none of them have battery/Solar.
My situation is I only charge my car during the day because I have a 9.6Kw solar battery system and our Tesla is 99% of the time a light daily driver so it’s essentially 100% powered by our solar. The batteries provide all the power we need from 4pm to the next day where they get fully charged by 10-11am and I’m on solar all day with plenty going back to the grid, even with car charging.
The rub for me getting an EV plan is that the off peak charge is horrendously high, and exactly when I MIGHT have to tap into the grid if I underproduce solar, while my nighttime off peak grid usage is always zero.
I’m constantly wondering if I’m doing it right…
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Since you have solar and are overproducing, you're fine on ETOU-C. EV2-A can be advantageous with solar and batteries if you're paying money at true-up because you can charge during off-peak and then export during peak to generate more NEM credits. Since you'll have extra credits that expire anyway, that won't help you.
