Off-Peak and Time-of-Use EV Charging

On a flat electricity rate, when you charge does not matter. On a time-of-use plan, it can matter as much as the rate itself. Many utilities offer time-of-use pricing where overnight power is far cheaper than afternoon power - and since an EV charges while you sleep anyway, it is close to a free lunch. This guide explains how those plans work and how to make your charging hit the cheap hours automatically.

What a time-of-use plan is

A time-of-use (TOU) rate charges different prices for electricity at different times of day. Typically there is an expensive on-peak window (often late afternoon and evening, when everyone is home and demand is highest), a cheaper off-peak window (overnight), and sometimes a mid-peak shoulder. Some utilities offer EV-specific plans with an especially low overnight rate designed to encourage charging when the grid is quiet. The spread between peak and off-peak can be large - it is common for off-peak to be a fraction of the peak price.

Why EVs and TOU plans fit together

An EV is the ideal appliance for a TOU plan because its big load is completely shiftable. You do not need the car charged at 6 pm; you need it charged by morning. So you move that entire load into the cheapest overnight window and pay the off-peak rate for most of the energy you use. On the right plan, this can cut your effective charging cost meaningfully below the flat-rate numbers in our cost to charge guide - the same energy, bought at a lower price.

How to charge off-peak automatically

There are three ways to make sure charging happens in the cheap window, from best to worst:

• Smart charger scheduling. A smart Level 2 charger lets you set charging to start at your off-peak hour and forget it. This is the cleanest approach and a big part of why a smart charger can pay for itself on a TOU plan.
• In-car scheduling.Most EVs can schedule charging from the car's own menus, which works with any charger, dumb or smart.
• A charger with a delay timer. Even some inexpensive portable chargers include a simple delay timer to start charging a set number of hours later - a low-tech way to hit off-peak with no app at all.

Is it worth switching plans?

For most EV owners who charge at home overnight, yes - a TOU or EV-specific plan usually lowers the bill, sometimes substantially. The way to know for sure is to look at your utility's TOU rate schedule, estimate how much of your total household usage (not just charging) falls in each window, and compare against your current flat rate. If the bulk of your big loads are already off-peak or shiftable, switching is close to free money. Either way, an EV that schedules its own charging to the cheap hours is the setup you want.