Grid ยท Analysis
Power Saver Rewards: getting paid to power down on the grid's worst evenings
On a few hot evenings each year, PG&E and California's grid operator pay a bill credit for cutting power between 4 and 9 p.m. Here is how the program works, and why the timing is the whole point.
I. How the signal reaches your phone
The fog that usually sits over the Sunset and the Richmond by late afternoon pulls back for a few days each September, and the city warms in a way San Francisco rarely does. On one of those evenings your phone buzzes with a message from PG&E: cut your electricity use between 4 and 9 p.m. tonight, and you will earn a credit on your bill. It is not an emergency order. It is an invitation with a price attached, and it only arrives on a handful of days a year.
CAISO, the California Independent System Operator (the agency that runs the state's high-voltage grid), watches evening demand, and when it is expected to run high PG&E calls a Power Saver Rewards event, usually notifying enrolled customers the day before or the morning of. Events land in the 4 to 9 p.m. window because that is when rooftop and large solar fade with the sunset while demand from air conditioning, cooking, and EV charging stays high. The season typically runs May through October, and at last public report PG&E automatically enrolls many eligible residential customers, so for most San Franciscans there is nothing to sign up for. You check your account to confirm, and every event stays voluntary.
II. How the baseline is measured, and why it is slippery
Your credit is paid for every kilowatt-hour (a unit of electricity, roughly what a small window air conditioner draws in an hour) that you trim below a baseline, and the baseline is an estimate of what you would have used with no event at all. PG&E's program materials describe building it from your metered usage on several recent, similar days, so your reduction is the gap between that estimate and what your meter actually records during the event hours. The credit is about a dollar per kilowatt-hour at last public report, which keeps the real money modest for most homes.
This method is reasonable but not magic. If your recent days already ran cool and low, the baseline is low and there is little room to beat it, and if you precool the house at 2 p.m. to coast through the evening, that earlier use can nudge the baseline up. The honest read from this desk: treat the credit as a small reward for good timing, not a budget line you can plan around.
III. Why your 6 p.m. kettle matters on these days
On the tightest evenings CAISO leans harder on natural gas peaker plants (units that mostly sit idle and fire up only when demand spikes), because solar has dropped off for the day and batteries can only cover so many hours. Every kilowatt-hour trimmed across thousands of homes at 6 p.m. is one the grid does not have to pull from those plants, which is why a voluntary program aimed at a few hours on a few days can still matter.
San Francisco's own supply is cleaner than most, between CleanPowerSF (the city's community choice program, which buys greener power while PG&E still runs the wires and the meter) and Hetch Hetchy Power (the SFPUC's public hydroelectricity from Sierra reservoirs). The program still runs on PG&E's meter, so a CleanPowerSF customer in Bernal Heights participates the same way a bundled PG&E customer does. The payoff is regional: your trimmed load helps the whole California grid on the few evenings it leans on gas, even when the fog has kept your own block cool.
IV. Worth watching this month
1. PG&E's Power Saver Rewards season typically runs May through October, so expect few or no events now and watch for the program's return next spring.
2. CAISO posts grid conditions and any late-season alerts on its public site, worth a look whenever an unusual November warm spell lingers.
3. The CPUC's Emergency Load Reduction Program proceeding is where any change to the credit rate or the rules would appear, usually routine filings but the place to confirm next year's terms.
4. Your PG&E account page shows enrollment status and any credits earned this season, which generally post on a later bill rather than the same day.
5. Watch for CleanPowerSF or SFPUC notices on how their customers take part, since the program is tied to PG&E's meter rather than your generation provider.
Frequently asked questions
Do I have to sign up?
At last public report PG&E automatically enrolls many eligible residential customers, so check your account rather than assume you are in or out. You can also opt out if you prefer.
How much can I actually earn?
The credit is roughly a dollar for each kilowatt-hour you trim below your baseline during an event. For most homes that is a modest amount, and it depends entirely on how much you cut.
What counts as cutting back?
Shifting big loads out of the 4 to 9 p.m. window helps most: running laundry and the dishwasher earlier, holding off on EV charging, and precooling the house before the event starts.
Does being on CleanPowerSF or Hetch Hetchy change anything?
No. The program runs on PG&E's meter and delivery, so your generation provider does not change whether you can take part or how the credit is measured.
Will I lose power if I ignore a message?
No, it is voluntary. The only thing at stake is the credit, not your electric service.
References
- CAISO, Today's Outlook (grid operator), Live grid conditions and demand for the California system, where tight evenings and any public alerts show up., www.caiso.com/todays-outlook.
- CPUC, Emergency Load Reduction Program (state agency, .gov), The California Public Utilities Commission proceeding behind the program, including the credit structure and rule changes., www.cpuc.ca.gov/elrp.
- PG&E, Power Saver Rewards (utility program page), How enrollment, events, the baseline, and the per-kilowatt-hour credit work for PG&E customers., www.pge.com/en/save-energy-and-money/energy-saving-programs/power-saver-rewards.html.
- CleanPowerSF (city community choice program), San Francisco's community choice aggregator, for how city customers are served while PG&E delivers the power., www.cleanpowersf.org.
- SFPUC, Hetch Hetchy Power (city agency, .gov), The San Francisco Public Utilities Commission's public power service and its Sierra hydroelectric supply., www.sfpuc.gov.