Which US electricity plans have the biggest peak to off-peak gap?

Method

For every residential tariff we publish that prices electricity by hour, we took the highest and lowest first-tier energy rate across all of its periods, including any fixed adjustment, and divided one by the other. Tariffs with no intraday variation are excluded, as are farm, irrigation, master-metered and large-service schedules that utilities file under the residential sector but which do not describe a household.

Every rate comes from a tariff filed with a state regulator and republished in the NREL Utility Rate Database. We include only plans currently in effect and open to new customers. The source document is linked from each plan’s page.

The distribution

The shape here is the finding. A median of 2.6× describes a market where most time-of-use plans offer a real but modest incentive — enough to reward moving a dryer, not enough to reorganize your life around. But the ninetieth percentile sits at 5.1×, and the extremes go far past that. Averages describe this market badly.

The twenty widest

What the top of the list has in common

Three patterns recur, and none of them is an accident.

Electric vehicle tariffs. A utility can afford to offer a very cheap overnight rate precisely when the customers taking it are the ones who will use it overnight. Several of the steepest plans here are EV-specific, and some meter the car separately so the punishing peak rate never touches the rest of the house.

Critical peak pricing. Some tariffs reserve an extremely high price for a handful of declared event days a year, in exchange for lower prices the rest of the time. The headline ratio looks alarming, but it applies for perhaps forty hours annually. Read the tariff before judging one of these by its ratio alone.

Solar and net metering schedules. Plans designed around rooftop solar tend to have exaggerated time signals, because the whole point is to price the hours when solar is not generating differently from the hours when it is.

Why a big ratio is not the same as a big saving

A ratio is a lever, and levers do nothing until something moves. A household that cannot shift consumption out of the peak window will simply pay the peak price — and on most of these plans, the off-peak rate is cheap precisely because the peak is expensive enough to make up for it.

The useful conversion is: (peak price − off-peak price) × kilowatt-hours you can move × 365. On the steepest plan in our index by that measure — Southern California Edison Co’s TOU-D-5-8PM-CPP — a single kilowatt-hour a day moved out of the expensive window is worth about $430 a year. Whether that is a lot depends entirely on what you can move, which is the subject of a separate guide.