Time-of-use tariffs price electricity differently by period so home EV charging can be steered into cheaper overnight or solar-aligned windows. They only save money if most of your charging, and ideally other flexible loads, land in those windows while you avoid expensive peak periods. Standing charges still apply separately from unit rates. Smart chargers, vehicle timers and supplier apps must be set consistently. Treat published example rates as illustrations. Compare your actual tariff schedule, exit fees and whole-home usage before switching.
What time-of-use means in practice
Instead of one flat unit rate, you may see a cheap overnight band, a higher daytime band and sometimes a peak evening band. EV-specific products often require a smart meter and a compatible charge point or schedule.
Savings come from shifting kWh, not from renaming the same consumption. If you charge when you get home at 6pm every day on a tariff that punishes that hour, the EV product can disappoint.
Matching charger schedules to the tariff
Set the charger or vehicle to start inside the cheap window and to reach the needed state of charge before departure. Add a buffer for cold-weather battery conditioning if you preheat from grid power.
When two systems both try to schedule, pick one primary controller to avoid conflicts. Check whether daylight saving changes are handled automatically.
- Confirm cheap window start and end times in writing from the supplier.
- Test one week and compare half-hourly data if available.
- Watch for higher day rates on non-EV household loads.
Standing charge and whole-bill thinking
A low overnight unit rate can sit beside a higher standing charge or weaker daytime rate. If the household uses a lot of electricity in the evening for cooking and heating, model the whole bill.
Illustrative rate cards in articles cannot replace your personalised quote from a supplier or comparison journey.
When a simple single rate is better
Drivers who must plug in on return from shift work, or who lack a smart charger, may gain less. Low-mileage PHEV users who only need a short top-up might also see limited benefit after the effort of managing windows.
Revisit the choice after a season of data rather than locking a narrative on day one.
Practical checklist before you switch
Verify smart meter readiness, charger scheduling features, exit fees on the current deal, and whether the tariff expects a particular hardware partner.
Keep notes of monthly miles and home versus public kWh so you can judge the switch fairly after two billing cycles.
Frequently asked questions
Do I need a smart EV charger for a time-of-use tariff?
It is strongly preferable. Some tariffs expect smart charging behaviour. Vehicle timers can help, but a smart wallbox usually makes household automation easier.
Are overnight rates guaranteed forever?
No. Products change. Read the tariff terms, price change rules and any requirement to keep a linked charger account active.
Will the price cap fix my EV night rate?
The Ofgem price cap constrains default tariff arrangements in a defined way. Many competitive time-of-use products sit outside a simple single capped figure. Check Ofgem guidance and your contract.
Can solar and time-of-use work together?
Yes, with careful settings. Daytime surplus may cover some charging, while cheap overnight rates cover the rest. Avoid exporting cheaply then importing expensively through poor automation.
Core buying guides
Start with these high-intent guides, then dig into the rest of the library.
Related guides
Sources and further reading
How this guide was prepared
This guide was written by the Local EV Installers Editorial Team. We compare official guidance, legislation and established consumer information, separate general information from project-specific advice, and show publication dates and sources. We do not accept installer accreditation claims at face value.