Welcome to Tesla Motors Club
Discuss Tesla's Model S, Model 3, Model X, Model Y, Cybertruck, Roadster and More.


Hi, has anyone with solar, powerwalls and ev chosen TOU-D-4-9PM instead of the TOU-D-PRIME rate? I have solar (10kW), powerwalls (2x) and ev (low miles, not everyday) and think that more money can be made or saved with TOU-D-4-9PM than TOU-D-PRIME, even with its outrageous onpeak "all the time" during winter months.

With TOU-D-4-9PM you get a baseline credit every month, for me it appears to be around 350kWh at 0.07c, which is $24.5 per month for winter months. Daily charge is only 0.03c, and if you dont pull any power for that day an extra 0.35c daily charge.

With TOU-D-PRIME you have a 0.4c daily charge.

I went over the numbers and for me I think TOU-D-4-9PM might earn $1k vs TOU-D-PRIME earning $500. The numbers earned are most likely incorrect, but bottom line is that 4-9 is more advantageous than PRIME. Has anyone looked into this indepth? Are there extra charges they are not telling me about? I can share my calculations more if anyone is interested.


Grid Specialist
Supporting Member
Mar 4, 2018
Arcadia, CA
For me, with a nearly identical setup (12kW solar, 2 PW) the SCE comparison shows PRIME lower than TOU-D4-9 by a lot. But the comparison was done based on my past usage, which is TOU-D-A and I have my PWs set to discharge 2-8pm instead of 4-9pm, so it is skewed. The biggest drawback to PRIME is the ridiculous $0.40/day or nearly $12/month basic charge. The day and night low off-peak rates are great for EV and pool pumps, but won't return much on solar. So I haven't decided which to switch to when the time comes... I able to stay on TOU-D-A for now.

Did you have solar prior to the powerwalls? Were you previously on a TOU rate before the switch at PTO?

I am in the final stages of adding powerwall to my home (already having had solar for 4 yrs) and would not be happy if I was forced to switch out of TOU-D-A with NEM 1.0 before the 5 yr grandfathered mark.

I did not have solar prior. Solar + powerwalls installed. Previously I was on a tiered plan.
Hi troptop, would love to see your numbers. I'm in the same boat with SCE. Unfortunately I lost TOU A some time ago, so I've been on Prime. The 40 cent/day charge is obnoxious, but hard to beat 13 cents a kWh. Now that I have Powerwalls, though, I can duck the peak rates and sell back a lot during the afternoon to offset early AM car charging. Wondering if it might make more sense to go with a plan with higher overall rates (which I hope to offset), and no 40 cent per day charge. Prime has no baseline credit either, but I believe TOU-D-4-9PM does.

The only other charge I'm subject to is the NBCs that come along with NEM 2.0. If you avoid pulling from the grid, I believe you can avoid the NBCs as well. I think those are like 2.5 cents per kWh pulled even if the kWh is offset.

I ll get back with numbers, since I need to find them and also some news:
1. sce's rates have increased quite a bit on january 1st!
2. turns out my electricity is from Clean Power Alliance, and on their website you can opt for how your energy gets generated and you get charged accordingly. I chose 100% green so that I get highest ratest, so that when energy is sent back I get paid most. I ll come back with numbers.
First I approximated my production using pvwatts and compared it to my usage for the previous year:
Month        AC Energy  
        ( kWh )  Production Past Usage
January        1021    1209
February        1084    1171
March        1549    1106
April        1710    992
May        1886    866
June        1892    1173
July        1942    1172
August        1868    1114
September        1574    1000
October        1357    907
November        1077    928
December        912    1061

About Us

Formed in 2006, Tesla Motors Club (TMC) was the first independent online Tesla community. Today it remains the largest and most dynamic community of Tesla enthusiasts. Learn more.

Do you value your experience at TMC? Consider becoming a Supporting Member of Tesla Motors Club. As a thank you for your contribution, you'll get nearly no ads in the Community and Groups sections. Additional perks are available depending on the level of contribution. Please visit the Account Upgrades page for more details.