Explainer
One hour earlier could save your business £2,000 a year. Or nothing at all.
Electricity costs far more to deliver at peak times. Move your heavy work out of those hours and the price per unit can drop by a third.
Take a care home in Plymouth. Its laundry goes on at 5pm every day, after the afternoon changeover.
Say the manager moves it to 4pm. Same staff, same machines, one hour earlier.
The care home would pay about a third less for every unit of electricity that laundry uses. Over a year, that’s more than £1,000.
A hotel down the road could do the same with its laundry and kitchen dishwashers, and save about £2,000.
Why does one hour matter?
On most business contracts, you pay the same for the energy itself at 4pm as at 5pm. The difference comes from the network charge: what your local network company charges to carry electricity to your door.
That charge changes through the day. In peak hours (known as the red band), the network charges far more for every unit. That’s the whole of the jump you see on the map below.
On its own, the network charge rises a long way. In Plymouth it’s about 14 times higher at 5pm than at 4pm. It’s only one part of what you pay, though, so the effect on your whole price per unit is smaller: at 4pm it’s about a third lower than at 5pm. In real life, that’s the £1,000 a year for the care home’s laundry.
Britain has 14 local networks, and each one runs its own clock. Peak hours fall in the late afternoon and early evening, somewhere between 4pm and 7:30pm. London has a second peak at lunchtime. They only apply Monday to Friday. At weekends there are none.
In Plymouth, peak hours start at 5pm. Run something at 4pm and you miss them.
4pmweekday
- Peak hours (red)
- Amber
- Green
Will it work for you?
It depends on three things: where you are, your meter and your contract.
Where you are. Put the same care home in Leeds and the move saves nothing. Peak hours there start at 4pm, so 4pm costs just as much as 5pm. If you don’t know your peak hours, you can’t plan around them.
Your meter. If you’re on a half-hourly meter, this applies to you today. The meter records how much power you use in every half hour, so your supplier knows whether you used it at 4pm or 5pm. Most larger business sites already have one. To check, look at your supply number (MPAN) on your statement. If the top line starts with 00, you’re half-hourly.
If you’re not, it’s coming. The industry is moving every site in Britain onto half-hourly data, a change called market-wide half-hourly settlement (MHHS). Smaller businesses are switching over now, so knowing your peak hours will matter to far more firms soon.
Your contract. If your statement shows separate red, amber and green rates, moving your usage saves you money straight away. That’s standard on pass-through contracts, which larger businesses are most likely to have, and some fixed contracts price by time of day too. If you pay one flat rate, you won’t see it straight away, but suppliers price your next contract on when you use power, so a better pattern can still pay off at renewal.
What could you move?
Most businesses run something that doesn’t need to happen at a set time. A few common ones:
- Laundry and tumble dryers
- Kitchen dishwashers and glass washers
- Hot water tanks that heat on a timer
- Electric vans that go on charge when the drivers get back
- Heavy machines that start up at the end of a shift
Look at what runs in your peak hours. If it could run an hour earlier, or wait until the peak ends, you pay less for the same work.
What to do next
Speak to your energy broker. They can look at when your business uses the most power and advise you on ways to cut your costs, from moving work out of peak hours to wider efficiency measures.
Want to check your own peak hours first? Grid Clock Live shows them for any postcode in a few seconds.
Check your peak hoursQuestions? hello@energycode.ai
Rough figures for a half-hourly metered site in the South West on the LV site-specific tariff, at 2026-27 network rates. Peak hours apply on weekdays, including bank holidays. The price per unit includes an estimate of 25p for energy, levies and other costs. Your contract may differ.