# Time-of-use electricity: shift AC costs without sacrificing comfort

Canonical: https://www.savpwr.com/knowledge/time-of-use-ac
Market: United States
Author: SAVPWR Editorial (VDX Logic LLC)
Published: 2026-11-09
Sources checked: 2026-11-09

## Will a smart thermostat reduce my bill on a time-of-use plan?

Only if the operating schedule, tariff and building response produce a useful tradeoff. Shifting electricity to a cheaper hour can lower cost without lowering total kWh; a thermostat is not a guaranteed savings device.

## Get the actual tariff

Identify peak hours, weekday and seasonal rules, demand charges if present, and exceptions. Use your own utility plan. A national or state average electricity price cannot establish the value of shifting a particular afternoon load. [1]

## Test a modest schedule

Programmable controls can adapt temperature schedules to occupancy. For heat pumps, confirm that recovery settings do not unnecessarily activate resistance backup. Keep comfort needs and household health constraints ahead of tariff experiments; avoid aggressive changes during extreme heat. [2]

## Measure cost and energy separately

Compare interval consumption by rate period and note outdoor weather, occupancy and setpoints. A cheaper bill with higher kWh may represent shifting rather than improved efficiency. Stop a schedule experiment if occupied rooms become uncomfortable, and avoid assigning savings without a comparable baseline.

## Decision exercise

Shifting a hypothetical 3 kWh from $0.45/kWh to $0.15/kWh saves $0.90 on that day if total consumption stays unchanged. If pre-cooling adds another 2 kWh at $0.15, net savings fall to $0.60. The building response is a measurement question, not a fixed platform assumption.

Numbers are illustrative assumptions, not forecasts.

## Preparation checklist

- Save the tariff name and current effective date.
- Keep a log of comfort, interval use and setpoints.
- Have a professional verify heat-pump recovery controls.

## Does pre-cooling work for every home?

No. Insulation, thermal mass, humidity, equipment capacity and tariff details change the result.

## Sources

[1] U.S. EIA — Electricity Prices and Factors Affecting Prices: https://www.eia.gov/energyexplained/electricity/prices-and-factors-affecting-prices.php
[2] DOE Building Science Education — Programmable Thermostats: https://bsesc.energy.gov/energy-basics/hvac-programmable-thermostats

AI-assisted preparation; no licensed professional review is claimed. Editorial policy: https://www.savpwr.com/editorial