What Is a Demand Charge? (And Do California Residential Customers Pay One?)

The Simple Definition

A demand charge bills you based on the highest electrical load (kW) you drew during the billing period; typically measured as a rolling 15-minute peak. It's separate from your per-kWh energy charge. You pay both: energy charges for how much total electricity you used, and demand charges for how big your biggest moment was.

Analogy: energy charges are like paying for gallons of water used; demand charges are like paying extra because you opened every faucet in the house at once for 15 minutes.

A real example: PG&E's Schedule B-19, for business customers whose demand reaches 500 kW (and an option below that), charged $37.37 per kW of maximum demand at secondary voltage from March 1, 2026, plus $46.16 per kW of peak-period demand in summer. For customers above 499 kW, PG&E averages demand over 15-minute intervals (PG&E Electric Schedule B-19, checked September 24, 2026).

Who Actually Pays Demand Charges?

• Commercial customers — larger business rate schedules include demand charges; the PG&E B-19 example above shows how large they can be. Check the schedule named on your own bill.
• Industrial customers — always, at higher per-kW rates.
• Some residential customers — PG&E, SCE, and SDG&E have piloted or offered residential demand-charge rate plans, but they are opt-in and not the default. Most California residential customers do not pay demand charges directly.
• EV high-power charging — commercial DCFC sites pay demand charges that often exceed the energy charges themselves.

Why Utilities Bill This Way

The grid is sized to handle everyone's peak demand simultaneously. If every business runs AC, pumps, and lighting at 3 PM on a hot day, the utility needs enough capacity to handle that simultaneous load. Demand charges recover the cost of having grid capacity standing by for your biggest moment, regardless of whether you used much total energy.

How Solar and Battery Reduce Demand Charges

• Solar lowers energy charges but often doesn't eliminate demand charges. Your peak demand often happens on cloudy days or at dusk when solar isn't producing.
• Batteries are specifically effective against demand charges. A battery can discharge during your peak-load window, clipping your billing peak even if solar isn't producing.
• Smart energy management (Span panel, Generac Ecobee-style controls) that throttles loads automatically when approaching a demand threshold is an emerging category for commercial customers.

If You Run a Business in California

Battery storage is the usual tool for demand-charge management. The federal commercial credit under IRC § 48E is 30% for a facility under 1 MW AC or one meeting prevailing-wage and apprenticeship standards; SGIP's non-residential storage categories have closed, so check the official tracker before counting on a rebate. Payback depends on your demand-charge rate, how many kW the battery can shave and its installed cost, so ask each bidder to show that arithmetic. Storage is treated better than solar here: § 48E(e)(4)(C) exempts energy storage technology from the 2027 wind-and-solar termination, so the deadline pressure that applies to the panels does not apply to the battery itself.

See our Commercial SGIP Battery Storage Guide for details, and price the solar side of the project against commercial solar cost per watt in California before you accept a payback figure from a bidder.

Related Reading

• How Does Net Metering Work?
• Net Billing vs Net Metering (California)
• Commercial Solar in California