Skip to content
WattWise

Electricity rates

Time-of-Use (TOU) Rates: How to Optimize EV Charging to Save $800 a Year

How utility time-of-use rate plans work, off-peak super-saver hours, and how to program vehicle charge timers to slash electricity bills.

By the WattWise Editorial Team 7 min read

Charging an electric vehicle adds roughly 3,000 to 4,500 kilowatt-hours of electrical demand to a household annual utility bill — an increase of 30% to 45% in total electricity consumption. If you charge your vehicle under a standard flat-rate utility plan, your electric bill will rise predictably.

However, enrolling in your utility’s specialized EV Time-of-Use (TOU) Rate Plan and scheduling vehicle charging strictly during off-peak overnight hours can cut your charging fuel costs by half.

How TOU Rate Pricing Tiers Function

Electric utilities experience massive demand surges between 4:00 PM and 9:00 PM when families return home, run air conditioning, and prepare dinner:

  • On-Peak Hours (4 PM–9 PM): Peak generation costs. Electricity rates can reach $0.40 to $0.60 per kWh.
  • Off-Peak / Super Off-Peak Hours (Midnight–6 AM): Low wholesale demand. Power plants generate base-load wind and nuclear energy with excess capacity. Rates drop to $0.08 to $0.15 per kWh.

Plugging your vehicle in at 5:30 PM when you arrive home but scheduling charging to begin at 12:01 AM automatically captures the lowest rate tier with zero manual effort.

Sources

Frequently asked questions

What is a Time-of-Use (TOU) electric rate plan?
A utility pricing structure where electricity rates change throughout the day based on wholesale grid demand, with high rates during afternoon peak hours and low rates overnight.
Can you program an EV to only charge off-peak?
Yes. Almost all modern EVs and smart home chargers have built-in smartphone apps where you set scheduled charging windows (e.g., start at 12:01 AM).

About the author

Written by the WattWise Editorial Team, which researches and maintains every guide on this site. Read more about our editorial standards or contact us with corrections.

Keep reading