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Tesla Virtual Power Plant in CA
- Thread starter power.saver
- Start date
aesculus
Still Trying to Figure This All Out
I got a note today stating they finally figured out that I was eligible and to please re-apply. I did so just so I can, but not sure if I will actually turn it on when approved. TBD and it may take a week or so for approval, so I will probably miss the events I expect over the next week.
It's a 3 hour event. That will suck a fully charged pw dry. So you end up using the grid at peak and partial peak time upto midnight in PGE land. Which may not be a bad trade off when you get $2 per kwh for exporting.
Didn't quite make it to 8 pm. I hit 5% (started at 100%) at 7:57pm. Oddly enough as it got lower the draw increased reaching about 14.5 kw (3 pws) right as it hit 5%.
PWs discharged a total of 35.4 kWh during the event with 29.6 kWh discharged to the grid for a total of $59.17. My model extracts this and figures it out for me. The app won't tell you how much of the discharge was for the house and for the grid numerically.
I've grand totaled just over $100 between the two events. The first event was cut short for me because the power went out in the neighborhood with 1 hour to go.
PWs discharged a total of 35.4 kWh during the event with 29.6 kWh discharged to the grid for a total of $59.17. My model extracts this and figures it out for me. The app won't tell you how much of the discharge was for the house and for the grid numerically.
I've grand totaled just over $100 between the two events. The first event was cut short for me because the power went out in the neighborhood with 1 hour to go.
Here is the PG&E VPP Fleet Home data that I collected for the event that just concluded at 10 minute intervals The peak was at 6:00pm with 18,867 kW with an estimated 45.1 MWh delivered during the event with 2,792 homes. At one point the homes was listed at 2,793 and at the end it was 2,791. My two Powerwalls discharged 23.2 kWh and end at 9%.
According to the Tesla 5 minute interval data, 21.6 kWh went to the grid over the 3 hours. That is a combination of solar and Powerwall discharge.
That doesn't really matter as the VPP compensation is based on the Powerwall discharge during the event minus the average from the 10 previous weekdays during the same time period.
An additional 2.2 kwh was used in Powerwall operatinos which is way more than normal for this time period. Presumably is was for cooling as the fans were like jet engines for the entire 3 hours.
What does the mean the average from the previous 10 weekdays. Average of what? Are you saying I didn't make $60 from the 30 kwh I discharged to the grid today from my powerwalls from 5 to 8 pm?
VPP pays on the extra discharge during the event from the baseline. The baseline is the average discharge for the same period for the last 10 weekdays or last 4 weekend days if the event is on the weekend.
If you normally only discharged 15 kWh from 5:00-8:00pm and discharged 45 kWh during the event then the difference is 30 kWh and that's worth $60.
I don't discharge anything to the grid from the powerwalls ever. The only two times have been these two events.
Discharge ro the grid versus discharge to the house is not relevant. VPP is just about discharge from the Powerwalls for the event period versus the baseline period.
See this post:
Tesla Virtual Power Plant in CA
as we all saw there was a recent grid event - when was it - I have no idea because once it's over there is no record of it in the app… hmmmm - if only there were a mechanism where Tesla "logged/recorded" discharge events like an "impact log" where they could list extended periods of time when...
teslamotorsclub.com
It looks like Tesla VPP uses the same avg that ohmconnect uses. For weekdays thats the average of NET usage over last 10 days, event days excluded.
The net usage includes discharge to the grid from your solar, which happens if you use your pw to power your home during peak hours while the sun is out.
So your baseline could be negative to start out with and not just zero. For example, I know someone with a roughly 9kw system and their baseline avg for this last event was -5.kWh because of the solar power sent to the grid between 5-8pm on avg. So if during the event they sent 12kWh total their net profit would be 12-5 = 7 7x2 = $14.
It's all about the baseline.
The danger of using all your PW juice during these events is that you have nothing left if the power really goes out which there is a higher likely hood of during flex alerts.
for a financial return comparison between ohmconnect and Tesla VPP:
Tesla VPP vs Ohmconnect
For powerwall owners who are net exporters Ohmconnect is much more lucrative then Tesla VPP at this point. If you do the bare minimum and set your reserve and select export everything you will quickly reach the max payout of $1 for every 635watts exported. Which comes out to about $15.74 per...
teslamotorsclub.com
I'm always surprised people are willing to discharge down to < 10% for these events and will have no battery left if a real power outage hits after 8pm. I'll just sit with my reserve at 60% right now during the summer and miss out on the $~50 per event since I'd feel bad and get the wife complaint that "We have ESS and no power now and you used up all the batteries for that!?!?!"
If there was a real danger of rolling blackouts to prevent grid collapse then I likely would not participate, but this hasn't happened and really isn't a high risk factor as CAISO has been showing lots of reserves. Those reserves have higher pollution and higher cost, but not as high as the VPP pays currently.
We've never had a rolling blackout where I live in Merced. If it was a likely possibility, I'd probably keep my reserve to 30% instead of 5%. On non event days, I just have it set to the default of 20%.
This actually does not seem to be the case. See @Redhill_qik's comment above yours.
Although the math is the same, Tesla has opted to use submetering of the Powerwall output. This means solar has no impact (other than reducing the maximum export rate of the Powerwalls). Also, home usage will not count against the amount.
From my Tesla App:
Energy Discharged from the Powerwall (we have 3 PW2)
Date - kWh used (reserve left at end of peak)
8/31/2022 - 35.0 kWh (5%) *Event Day*
8/30 - 26.1 kWh (29%)
8/29 - 26.5 kWh (30%)
8/26 - 25.9 kWh (34%)
8/25 - 29.8 kWh (18%)
8/24 - 19.3 kWh (47%)
8/23 - 21.8 kWh (42%)
8/22 - 19.1 kWh (48%)
8/19 - 31.6 kWh (15%)
8/18 - 28.8 kWh (22%)
8/17 - 35.0 kWh (5%) *Event Day*
8/16 - 24.7 kWh (33%)
Average of last 10 weekdays (other event day excluded) = 25.36
Does this mean I would only get credit for 35.0 - 25.36 = 9.64 kWh for yesterday's event?
IDK how to adjust for the "event hours" since the 8/17 event was 6-9 pm and the 8/31 event was 5-8 pm for me.
The numbers I gave are for my peak period (4-9 pm TOU-B)
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The 10 weekdays if the event is a weekday is correct for Tesla VPP, but the baseline average is only for the Powerwall and your house load and solar are not a factor.
Agreed that it is all about the baseline and since a lot of people have configured their Powerwalls to cover all of the Peak period or are using the Export Everything option then their baseline will be high. If your average Powerwall discharge was -10 kWh during the event hours than that is your baseline.
You can game the system a little bit, but trying to avoid Powerwall discharge during event hours for non-event days. The best choice is probably pushing it to later in the peak period 7:00-9:00pm to avoid have solar still generating and recharging the Powerwalls if you went with 4:00-6:00pm. The other option, which I do not like at all and do not recommend doing, is to increase your house load so that your Powerwalls will discharge more. My PTO limits my grid export to 7.68kW, but two Powerwalls can export 10.0 kW. Increasing the house load by allowing the A/C to run, turning on an oven or charging an EV during the event will increase the discharge, but not violate the grid export. I was seeing a max of 7.80kW to the grid during both VPP events with Powerwall discharge up 9.8 kW.
Hmm, I was just looking at my 10 prior days worth of data and noticed that I had some negative numbers. I was playing around with different peak period start/stop times and must have used 4:00-6:30pm with an 80% reserve. The Powerwall discharged and then started charging again as the solar was still generating. That gives a third way, or maybe a just different take on the first way, to game the system, but one that is rapidly going away as sunset is getting earlier and earlier.
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