How to cut your energy bill
Guide · updated 2026-08-23
Most energy-saving advice is a long list with no numbers on it. Here is a short list, ordered by what each item is actually worth.
Worth hundreds a year
- Be on the right tariff. The gap between the worst and best tariff for a given household is routinely £100-£300 a year, and it costs nothing but a switch. The catch is that "best" depends on your own usage shape, not on a headline rate — compare against your own readings rather than a national average.
- Move heating and hot water off peak. If you have electric heating, storage heaters, a heat pump or an immersion heater, when they run matters more than anything else you can change.
- Charge an EV overnight. On the wrong tariff an EV costs as much as the rest of the house combined. On Go or Intelligent Go it is a fraction of that.
- Turn the heating down one degree. Roughly a 5-10% cut in heating energy, which on a gas-heated house is the largest single line in the bill.
Worth tens a year
- Wash at 30°C rather than 60°C — most of a wash cycle is heating water.
- Dry clothes on an airer instead of a tumble dryer, the most expensive routine appliance in most homes.
- Draught-proof doors, letterboxes and floorboards. Cheap, immediate, and it makes a house feel warmer at a lower thermostat setting.
- Set the hot water cylinder to run once a day rather than continuously, and time it for the cheap window.
- Switch to a direct debit if you are on a prepayment or standard credit tariff, which carry higher rates.
Mostly not worth it
- Unplugging phone chargers. A modern charger draws almost nothing when idle.
- Replacing LED bulbs with slightly more efficient LED bulbs.
- Boiling "exactly one cup" with a stopwatch. Boil less than you were, and stop there.
- Any gadget sold to reduce your bill by conditioning your supply. These do not work.
Measure before you optimise
The single most useful step is looking at your own half-hourly data. It shows what your baseline draw is at 03:00, what the evening peak costs you, and which appliance is responsible for the spike you cannot explain. Guessing which of the items above applies to you wastes more money than any of them saves.
See smart meters and half-hourly data for how to get the readings, then price them on the usage page.
Common questions
What uses the most electricity in a home?
Electric heating and hot water, where present, dominate everything else. In a gas-heated home the largest electricity users are usually the tumble dryer, oven, dishwasher and washing machine.
Does switching energy supplier actually save money?
Switching tariff does. The saving depends on your own consumption shape, so a comparison based on your real half-hourly readings is far more reliable than one based on a typical household.
Is it worth turning appliances off at the wall?
Marginally. Most modern devices draw 0.5-2 W on standby. Older set-top boxes and games consoles in rest mode are worth switching off; phone chargers are not.
See it on your own numbers. halfhourly.uk shows live half-hourly prices for every GB region for free, and if you connect an Octopus account it prices your own smart-meter readings against every tariff.