A home that buys power straight from the utility pays 34.5¢ in the cheapest hours and 72.6¢ during the evening rush [1]. A neighbor who buys through a community choice aggregator (CCA) pays 25.6¢ in all three periods for delivery [1]. A CCA is a local buying group that supplies the power while the utility still owns the wires. The gap between that neighbor’s cheapest and priciest hour is exactly 0¢. The battery and the roof match. The price gap the homeowner buys does not.

The big picture:

A battery does not earn a flat rate. It earns the gap between two hours, and whoever writes the bill sets that gap. In most of the country one company sells both the power and the wires, so it prices the two hours far apart on purpose. When a buying group supplies the power, the utility sells only the wires. Wire costs barely move from one hour to the next. Look at the second San Diego plan, which covers two periods.

A wires-only home sees 22.3¢ off-peak against 23.0¢ on-peak, which is a tiny 0.7¢ gap [1]. The bundled version of that exact same plan charges 31.0¢ against 58.9¢, opening a 27.9¢ spread [1]. One plan yields two contracts, and the spread is forty times wider on one side of the page.

The rule is not the same everywhere. That is why a buyer has to read the real price sheet instead of a sales flyer. On the electric car plan, the cheapest delivery rate drops to 4.7¢ while the peak stays at 31.8¢. Even a wires-only home gets 27.1¢ of room there [1]. That setup survives the split between power and wires.

What does not survive the split is a price sheet built on a flat wires charge. National averages hide this entirely. The U.S. Energy Information Administration (EIA) puts the 2025 average home price at 17.30¢ per unit, but state averages swing from 35.72¢ in Hawaii to 8.20¢ in North Dakota [3].

A payback model built on an average describes a house that does not exist. Seasons matter as much as the map. Consolidated Edison (Con Edison) charges $0.2786 from 8 a.m. to midnight between June and September, against $0.0522 off-peak [2].

In the other eight months the peak drops to $0.1711. The gap a battery can harvest falls from 22.64¢ to 11.89¢ [2]. The same hardware earns about half as much for two-thirds of the year. My read: the useful question is no longer which battery you buy, but which bill you pay. Every payback line in a quote is a bet on a schedule the salesperson has usually never seen.

By the numbers

  • 38.1¢ — Bundled on-peak gap: the storage plan prices 34.5¢ in the cheapest hours and 72.6¢ at peak for a customer who buys power from the utility [1].
  • 0¢ — Delivery-only gap: the same plan charges a CCA home that buys only wires 25.6¢ in every period [1].
  • 22.64¢ — Con Edison summer gap: the $0.2786 peak price sits against $0.0522 off-peak, and narrows to 11.89¢ outside June through September [2].
  • 6.09¢ — Payback threshold: with 5.0 kilowatt-hours (kWh) of usable storage at 90% efficiency, each cent of gap is worth $16.43 a year. So $1,000 of installed cost needs 6.09¢ to break even inside ten years [4]. Efficiency here means the power that survives one charge and one drain, so a tenth is lost.

What I’d watch:

  • The dual prices: both utilities print rates by period, and finding the true value takes one simple step. At a 0.7¢ gap, a 5 kWh battery cycling daily collects just $11.50 a year before any loss [1][4].
  • The supply line: San Diego notes plainly that a CCA customer must also pay for power at prices the aggregator sets [1]. The utility prints half the gap. The other half needs a second schedule.
  • The peak window: Con Edison runs its peak pricing sixteen hours a day in summer [2]. A small battery can only shift the load it covers inside that window. One cycle a day is a guess, not a promise.
  • The fixed charges: Con Edison adds a $21.00 monthly customer charge on top of prices that leave out extra fees [2]. San Diego leaves out a base fee that began in October 2025 [1].
  • The loss term: Enphase lists 90% round-trip efficiency for its 5 kWh home battery [4]. A tenth of the gap is lost moving power in and out of the cells, which keeps the true threshold above 5.5¢.

The catch

A battery is really two products sold on one bill. The first is the price gap, and its value is the spread. The second is backup power, and none of these numbers measure that safety. My read: a household that loses the grid twice a winter may wisely buy a battery that never pays back on the gap alone. That is the honest counter to everything above, and it explains why this piece prices only the first product. The spread is the only product the payback line claims to measure.

The numbers are narrower than they look. Two utilities and four plans are not a national survey. They are simply the price sheets I could pull and read in full. The battery here is a 5 kWh unit, and a larger one earns more per cycle without changing the threshold per dollar.

Rates move constantly. San Diego changed its numbers in August 2026, and Con Edison splits summer from the other eight months [1][2]. A reader in two years will find different cents in the same columns and the same math to do. What does not move is the core structure. Wherever a buying group supplies the power, it arrives on two bills, and a flat wires charge leaves almost nothing to harvest. Before signing a contract built on a generic guess, pull your own utility price sheet and compare it with the same battery across five states.

At a glance

  • The Big Shift: The payback on a home battery is set by the gap between a household’s peak and off-peak prices. That gap now differs sharply between a bundled customer and a CCA customer who buys delivery only.
  • Why It Matters: A quote carries a payback number that assumes a spread, but the spread belongs to the power contract rather than to the gear. Homes comparing quotes across a block or a utility line are often comparing two different products while looking at one box.
  • What I’d Watch: I am watching how these schedules get read, because the gap decides the return far more than the hardware does.
  • The subtraction: the difference between peak and off-peak prices on a specific schedule, which sets the true value of the quote.
  • The supply line: the buying group’s own price list that provides the missing half of the gap when the utility table covers delivery only.
  • The season: the shift in rates between summer and winter months, which sets the true yearly figure that repays the cost.
  • The Catch: The spread is only one of the two things a battery sells, and backup power has real value that no gap measures.

Related reading

Sources

[1] San Diego Gas & Electric, “When Matters” residential pricing plans (the two-period, storage and electric-vehicle plans; prices effective August 1, 2026) — https://www.sdge.com/residential/pricing-plans/about-our-pricing-plans/whenmatters [2] Consolidated Edison, “Time-Of-Use Rates” (residential) — https://www.coned.com/en/accounts-billing/your-bill/time-of-use [3] U.S. Energy Information Administration, “Electricity explained: Prices and factors affecting prices” (2025 annual averages) — https://www.eia.gov/energyexplained/electricity/prices-and-factors-affecting-prices.php [4] Enphase, “IQ Battery 5P” product specification — https://enphase.com/store/storage/iq-battery-5p