Saw same thing. Some areas shut down earlier than us (and suspect transformer related but I heard transformer problems on Labor Day) but our area didn’t happen until the demand was precariously high. Also read/heard that PG&E contacted areas to shut down for a period yesterday. Not based on zip code or block or circuit but by usage.
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Norcal heat wave
- Thread starter getakey
- Start date
Saw same thing. Some areas shut down earlier than us (and suspect transformer related but I heard transformer problems on Labor Day) but our area didn’t happen until the demand was precariously high. Also read/heard that PG&E contacted areas to shut down for a period yesterday. Not based on zip code or block or circuit but by usage.
So were you paying a peak rate for the grid to run your ACs amounting to more than you were getting from the VPP plan?
Hopefully not. But that is how it works. It is more like "help your neighbors" versus "I am going make a lot of money".
I will be curious to see what the net is once the next bill comes.
aesculus
Still Trying to Figure This All Out
Do you think it will be on the B/W bill? That would be nice.
I got the impression that Tesla was paying us for this and it could be a year before we see a payment. And if that is true, aligning all of this will be next to impossible.
Oh. Maybe it is like when lawmakers bury the pork and special carve outs in a bill?
My 5 ton 10 SEER AC unit installed in 1998 (common area...bedrooms is a 4 ton unit) uses 4900 watts when it's 110F outside and about 4600 watts when it's 100F outside. The blower uses 790 watts.
The 21.5 SEER mini split I'm about to install should use half the power for the same rate of cooling.
That would probably be very rare unless you used enough AC that absent the VPP event you would have depleted the powerwall and been drawing peak power anyway or the duration of the event and/or export limits prohibits you have discharging the powerwall to the reserve during the event hours. Otherwise, you are making up the peak draw with the energy you are sending back to the grid during the event except for the NBCs. On top of that unless you have a very high baseline (i.e. regularly use export everything) you get the $2/kWh credit which quickly makes up for the NBCs.
Since we are potentially pulling power from the grid during the event and before the event, does this mean the net event credit is:
(# of kWh sent * $2) - ((# of kWh used during event * peak rate) + (# of kWh used during pre-event * pre-event rate(s))
ignoring NBCs and assuming the event is during peak rate times?
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It's a bit more complex as the $2/kWh compensation is based on the amount of PW energy discharged during the event (all that power doesn't necessarily make it to the grid) relative to your baseline energy discharge on previous non-event days whereas your normal energy charges/credits are relative to the power flow to/from the grid.
That is my understanding, but you also get NEM credit for the export I believe. Plus when AC is running what you can export is lower, so net on these really hot days is probably very little. Now if you always have a ton of NEM credit left over anyways I guess it doesn't matter, but I think this month I may end up debiting from my NEM balance because of all the peak usage.
As others have mentioned, the $2 is credited based on discharge above your baseline (average over previous non-event days during the same period).
Regular billing/credits still apply, though, so you will actually gain some extra credit there if you would have discharged during at non-peak rate. Your NEM credits during the event are: (#of kWh exported * peak_rate). This means that if you join the event and discharge at least as much as you would have to cover your usage, you are at the very least breaking even (ignoring NBCs). Any extra export over and above what you would have normally discharged nets you both more NEM credits (at peak rate) and the $2/kWh. If you would have discharged outside of peak, you would also get a slight extra credit because you are now discharging at peak instead.
I think come March 2023 when Tesla sends out checks that a lot of people are going to be disappointed and the biggest people that will be disappointed will be the ones that have 0 kWh Peak imports. The Export Everything group might be pleasantly surprised if their discharge is complete by 7:00pm.
I went through the pain of have been pulling my 5min daily data from the Tesla app and here is what I am calculating so far.
| Event Day | Event Date | Period | Hours | PW Discharge | PW Baseline | ILR | VPP Comp |
|---|---|---|---|---|---|---|---|
| Wed | 8/17 | 6:00-9:00pm | 3.0 | 22.9 | 5.7 | 17.2 | $34.40 |
| Wed | 8/31 | 5:00-8:00pm | 3.0 | 23.2 | 5.7 | 17.5 | $35.00 |
| Thu | 9/1 | 6:00-7:00pm | 1.0 | 8.4 | 2.2 | 6.2 | $12.40 |
| Sat | 9/3 | 6:00-8:00pm | 2.0 | 17.8 | 1.5 | 16.3 | $32.60 |
| Sun | 9/4 | 5:00-8:00pm | 3.0 | 23.7 | 3.9 | 19.8 | $39.54 |
| Mon/Holiday | 9/5 | 6:00-9:00pm | 3.0 | 24.7 | 1.5 | 23.2 | $46.40 |
| Tue | 9/6 | 6:00-9:00pm | 3.0 | 19.4 | 2.8 | 16.6 | $33.20 |
| Wed | 9/7 | 6:00-9:00pm | 3.0 | 23.0 - estimate | 2.8 | 20.2 | $40.40 |
| Total | 21.0 | 163.1 | 137.0 | $273.94 |
I think that my baseline is much lower than most people will have as I was not aggressively using my Powerwalls during the Peak period as a net generator. I had them setup up originally to discharge from 6:30-9:00pm with a reserve level of 80%. After better understanding the program compensation I changed to 4:00-7:00pm to avoid discharging during most of the event hours to lower my baseline.
How did you calculate your baseline? I am usually in TOU mode and my PW will discharge enough to power my home since I still have solar available until maybe 7PM. Does the discharge for that count also? My baseline might end up being pretty high especially when the AC is running a lot.
I calculated it very painfully my downloading daily data from the Tesla app for 8/16 to 9/6, splitting the timestamp into day and hour cells, and using a spreadsheet with "sumif" functions multiplied by 5/60 to calculate the baseline kWh data for selected baseline days and hours based on manually created days. For instance this is a table for 8/3/22 with all of the data pulled from the another sheet with all of the downloaded data.
| Day | Date | 17 | 18 | 19 | kWh | |
|---|---|---|---|---|---|---|
| VPP | Wed | 2022-08-31 | 7.23 | 7.23 | 9.02 | 23.48 |
| 1 | Tue | 2022-08-30 | 2.31 | 1.40 | 0.00 | 3.71 |
| 2 | Mon | 2022-08-29 | 2.36 | 0.00 | 0.00 | 2.36 |
| 3 | Fri | 2022-08-26 | 3.88 | 0.93 | 0.00 | 4.80 |
| 4 | Thu | 2022-08-25 | 2.20 | 1.60 | 0.00 | 3.80 |
| 5 | Wed | 2022-08-24 | 2.83 | 0.98 | 0.00 | 3.81 |
| 6 | Tue | 2022-08-23 | 2.03 | -0.08 | 0.00 | 1.94 |
| 7 | Mon | 2022-08-22 | -0.18 | -0.03 | 0.00 | -0.21 |
| 8 | Fri | 2022-08-19 | 3.41 | 0.00 | 0.00 | 3.41 |
| 9 | Thu | 2022-08-18 | 1.89 | 0.03 | 0.00 | 1.92 |
| 10 | Tue | 2022-08-16 | 1.33 | 5.00 | 0.05 | 6.38 |
| Average | 2.20 | 0.98 | 0.01 | 3.19 | ||
| ILR | 20.29 |
I could post my spreadsheet, but my data is useless for anyone but myself.
Regarding charging during the day - more specifically during hours of solar production - CAISO publishes some very interesting curtailment statistics for wind and solar. Charging during the day can significantly benefit the grid, particularly during spring.
California ISO - Managing Oversupply
You can drill down to daily curtailment reports, which is pretty cool. My provider doesn't offer stats anywhere near this informative.
Each 100,000 MWh could enable 300 million EV miles at 3 miles per kWh. This April saw curtailment of almost 600,000 MWh. Smart workplace charging is relatively inexpensive and could be hugely beneficial.
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If you keep getting invite to join why don't you just join then turn it off in the settings after it is approved. I don't think you will even get event notice if you toggle it off in the settings.
Electrph
Member
Does same period mean same time? If so, then I am very good. I never send power back to the grid after 6PM. In fact, we hardly send any after 4 PM this time of year since we have shading from the hills to the West.
Yes. If the event is 6-9pm, your baseline is the average of your discharge from 6-9pm on the 10 previous non-event weekdays (or 4 previous non-event weekend days for weekend/holiday events). Again, though, it’s power exported from the Powerwall that counts, not power sent back to the grid (even if you used it yourself).
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