What is a time-of-use rate?
Utilities charge more for electricity during high-demand periods (peak) and less during low-demand periods (off-peak). A typical summer TOU schedule: Peak 4–9 PM at $0.35–0.50/kWh, Off-peak 9 PM–4 PM at $0.10–0.18/kWh, Super off-peak midnight–6 AM at $0.05–0.10/kWh. Winter schedules differ; some utilities have no winter peak.
Your bill shows total kWh per period. The per-period rate is usually listed in the rate detail section. If you don't see it, check the utility's rate tariff PDF or call customer service.
Biggest shift opportunities
EV charging: A 7.2 kW charger for 2.5 hours daily = 18 kWh. Moving all of it to off-peak at $0.12 vs. peak $0.40 saves ~$5/day or $150/month. Most EVs and chargers have built-in scheduling. Set it once and forget it.
Water heating: A heat-pump water heater can be scheduled to heat during super off-peak. Resistance tanks on a timer can heat overnight. Savings: $15–40/month depending on household size.
Laundry & dishes: Run washer, dryer, dishwasher after 9 PM. Delay-start features make this easy. Savings: $5–15/month.
Cooling: Pre-cool the house to 72°F by 3 PM, then let it drift to 78°F during 4–9 PM peak. The thermal mass of the home holds comfort. Requires a smart thermostat with TOU awareness.
- EV charging is usually the single biggest TOU win.
- Check if your utility offers a dedicated EV TOU rate — often simpler than whole-house TOU.
- Some utilities credit solar exports at off-peak rates only; verify before sizing.
Will TOU save you money? Run the numbers
Get 12 months of interval data (Green Button Data or utility portal). Calculate: (current flat rate × total kWh) vs. Σ(period kWh × TOU rate). If you can shift 30%+ of usage to off-peak, TOU usually wins. If your usage is already mostly off-peak (work from home, night owl), flat rate may be better.
Many utilities offer a 'shadow bill' comparison — they apply TOU rates to your actual usage for a trial period before you commit. Opt in, review after 3 months, opt out if it costs more.
Common pitfalls
Peak window varies: some utilities are 2–7 PM, others 4–9 PM, some split morning/evening. Verify your specific schedule.
Tiered rates inside TOU: some plans have baseline allowances per tier. Exceeding baseline in peak hours can be very expensive.
Holiday/weekend schedules differ. Solar customers: net metering credits may be at off-peak rates only.
Rate source and limits
The default rate is the EIA U.S. residential average for April 2026, retrieved July 16, 2026. It is an average revenue per kilowatt-hour, not a quote for your utility plan. Fixed fees, taxes, tiers, and time-of-use prices can change the bill.
Open the EIA source