A time-of-use (TOU) rate is an electricity tariff that charges different prices at different hours of the day, higher during the evening peak and lower overnight or at midday. In California the peak window on most rates is 4 to 9 p.m., which mirrors the hours grid batteries discharge.
What it signals
- TOU rates put a price on the duck curve: midday power is cheap because solar is abundant, evening power is expensive because it is not.
- Most California EV rates, residential and commercial, are time-of-use rates, sometimes combined with a demand charge or a kilowatt subscription.
Why it matters for parking
A workplace garage that charges cars between nine and five buys at the cheap hours by default. A residential garage that charges on arrival buys at the expensive ones. The tariff already tells an operator which side of the curve the facility is on.