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NorCal Powerwall owners. What is your reserve percentage right now? (Late October 2021)

h2ofun

Active Member
Aug 11, 2020
3,269
744
auburn, ca
I raise my Reserve as Fall progresses. I'm at 60% right now. Dead of Winter is 75% Reserve. Summer is usually 40%. My goal is to leave headroom above the Reserve for an ideal seasonal solar production day. My production Summer:Winter ratio is 5:1 kWh/day.
I still am at 15%, but with the rain and poor solar, the batteries will not recharge. Thinking up raising since going to pull from the grid one way or another, and why have dead batteries.
 

jboy210

Well-Known Member
Supporting Member
Dec 2, 2016
5,916
3,978
Northern California
I set mine at 25%, since I’m not going to get enough solar to charge the Powerwalls it really makes no different unless you are worried about a power outage. You will run off the grid once you reach your reserve.
I hate buying power, but hate even more being without power. So I will pay PG&E for a few days of being a "regular" customer. And amazingly, even with these overcast skies, the system has generated enough power to cover the 4-9 PM peak.
 

miimura

Well-Known Member
Aug 21, 2013
6,833
6,728
Los Altos, CA
I still am at 15%, but with the rain and poor solar, the batteries will not recharge. Thinking up raising since going to pull from the grid one way or another, and why have dead batteries.
Exactly. It's going to bounce off the Reserve daily, so why not keep enough energy for a backup event? The way I have it set, it will never hit 100% either.
 
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jboy210

Well-Known Member
Supporting Member
Dec 2, 2016
5,916
3,978
Northern California
Are you using Self-Powered mode? If you used Time-Based Control you wouldn't have to do that.
Even in Self-Powered mode, my system is following the schedule defined by the PGE plan I entered under Time-Based Control. That is, I see it switch to pulling from the Powerwalls from 4-9 PM M-F instead of the grid
 

clos000

Member
Jul 14, 2019
14
0
San Jose
Are you using Self-Powered mode? If you used Time-Based Control you wouldn't have to do that.

TBC sends my power to the Grid after it meets a reserve (let's say 25%). I would still need to change the power reserve to 100% to prevent it from being sent back into the grid.

Wish there was a way to have a preference to say charge up the battery first before outputting to grid. Or charge up the battery (from the grid) when it's cheap on overcast days.
 

bmah

Moderator, Supercharger Hunter
Global Moderator
Mar 17, 2015
4,489
9,001
Lafayette, CA, USA
50%, time-based control. With limited solar production due to cloud cover (especially the next few days), so I'd rather have more in reserve for an outage (we had an unplanned 11-hour outage last week). Like some other people here, I adjust my reserve percentage seasonally...it's as little as 30% during the summer.

Bruce.
 

zanary

Active Member
Jan 25, 2017
1,540
1,760
SF Bay Area (East Bay), CA
3 Powerwealls here, and my reserve is at 15%. We rarely have power outages since we had PG&E moved our neighborhood connection from one part of the grid that was under the PSPS area, to the other part that is NOT impacted by the PSPS.

I used the remaining for Time of Use to not get hit with the high cost under EV-A under Partial Peak or Peak.
 

miimura

Well-Known Member
Aug 21, 2013
6,833
6,728
Los Altos, CA
TBC sends my power to the Grid after it meets a reserve (let's say 25%). I would still need to change the power reserve to 100% to prevent it from being sent back into the grid.

Wish there was a way to have a preference to say charge up the battery first before outputting to grid. Or charge up the battery (from the grid) when it's cheap on overcast days.
If what you're saying is accurate, it is not typical. What schedule do you have set in the app, what rate plan are you on, and how much solar and Powerwall do you have?

I have a small solar system, two Powerwalls, I use TBC, and am on EV2-A rate plan. The Powerwalls take All Solar until they are full or the end of the Off-Peak period begins at 3pm. In the best generating months in the Summer, it will sometimes charge with Surplus Solar because it will have enough generation to fill to 100% before 3pm. Every day, it uses whatever is available above the Reserve to power the house during Peak hours 4-9pm. I only rarely have any PW discharge during Off-Peak, and that only happens when the SOC is very high in the morning. That typically only happens when we are not home in the evening to use power before 9pm.
 
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I have my reserve set at 40% for the rainy weather. I usually have it at 25%. The panels have been able to produce all the power needed by the house during the day with the overcast skies. It just only makes enough to add about 50% to the 4 PowerWalls which I think is still pretty amazing.

I want to make sure to have enough power in the batteries to keep everything on and charge the car a little for my wife’s work commute in case we lose power. I also don’t want the car charging when there is power to pull the batteries down extremely low, then have a power outage and an extremely overcast day.

I’m probably overreacting with the 40% reserve, but I’m still not drawing on PGE until after 10 and I am a net producer. I feel paying some NBCs for the next few days is worth it for the peace of mind.
 

astrorob

stealth performance M3
Aug 27, 2014
514
125
oakland, ca
i normally keep 40% in reserve but raised it to 100% for this AR. 60% of my 2 powerwalls is more than enough to cover 3-midnight.

i'd feel worse about not having power during a grid failure than i do about losing some money to PGE. on these cloudy days my system only produces 4-6kwh per day...
 

getakey

Active Member
Jan 28, 2020
1,575
530
95762
I'm set at 60%, but I also changed my Peak to a narrower range of 5pm to 9pm. I'm on EVA-1, so my real peak is 2pm to 9pm.
I reduced the Peak because my true-up was very negative when I was covering the full peak. I increased reserve to 60% during fire season and during the winter
 

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