A time-of-use rate charges different prices for electricity depending on when you use it, with the highest prices in a daily peak window, typically late afternoon and evening, and lower prices overnight. Many utilities require solar customers to take a time-of-use plan. Because solar production falls off before the evening peak, the timing of your use determines how much each kilowatt-hour of solar saves. Shifting flexible loads into sunny or off-peak hours, pre-cooling a home before the peak and adding a battery to cover the peak are the usual strategies. When an installer estimates your savings, ask which rate plan they modelled and whether it is the plan you will actually be required to use.
Related terms and pages
- Net billing: Billing in which exported solar is credited at a rate below what you pay for power.
- Self-consumption: The share of your solar output you use in your home as it is produced.
- Round-trip efficiency: The share of energy put into a battery that you can get back out.
- Home batteries compared