For most UK households in 2026, Economy 7 is only worth it if you can shift at least 40% of your total electricity use to the seven-hour off-peak window, according to energy regulator Ofgem (Ofgem, 2026). The typical Economy 7 tariff charges around 14p/kWh off-peak but 30p/kWh on-peak, compared to a standard single-rate tariff of 24p/kWh.
The deciding factor is your household’s heating and hot water system. Economy 7 works best with storage heaters or an immersion heater on a timer, where you can heat water overnight. If you rely on gas central heating, electric showers, or use most appliances during the day, the higher on-peak rate will likely outweigh any overnight savings. The Energy Saving Trust estimates that fewer than one in three households on Economy 7 actually save money compared to a standard tariff (Energy Saving Trust, 2026).
How to check if your usage suits Economy 7
First, look at your electricity meter. If you have a two-rate meter, it records separate readings for day and night usage. Compare the night unit reading to your total usage over a full year. If night usage is below 40% of the total, you are likely losing money. Ofgem recommends using a smart meter to get accurate half-hourly data, which many suppliers now offer for free (GOV.UK, 2026). If you cannot shift your major loads to the off-peak period, for example, by running your dishwasher, washing machine, and tumble dryer overnight, a standard tariff may be cheaper.
Storage heaters and hot water timing
Economy 7 is designed for homes with electric storage heaters. These heaters store heat overnight when electricity is cheap and release it during the day. A modern storage heater with a good thermostat and automatic controls can reduce heating costs by around 20% compared to running electric radiators on a standard tariff, says the Energy Saving Trust (Energy Saving Trust, 2026). For hot water, set your immersion heater to come on only during the off-peak period using a timer. If you heat water during the day, the on-peak rate will cancel out any savings.
Alternatives if Economy 7 is not for you
If your night usage is low, you can request to switch to a standard single-rate tariff from your supplier. Under Ofgem rules, suppliers must let you switch tariffs without penalty if you have a smart meter (Ofgem, 2026). For homes with electric heating, a heat pump with a dedicated heat pump tariff may be more cost-effective. The UK government’s Boiler Upgrade Scheme offers a grant of £7,500 towards an air source heat pump (GOV.UK, 2026). Always compare your actual usage against a standard tariff using a free online comparison tool before switching.
A worked example
A typical 1930s semi-detached house in the Midlands with electric storage heaters on an Economy 7 tariff can save around £290 a year after switching from a standard single-rate plan. This assumes the household uses 4,500 kWh of off-peak electricity annually for heating and hot water, meeting the 40% night-usage threshold. The upfront cost for a new set of modern slimline storage heaters is roughly £3,200, but the £7,500 BUS grant (for low-income households with off-gas heating) or ECO4 funding can cover most or all of this expense. Glazing is standard-rated for VAT at 20%. The zero rate for energy-saving materials covers insulation, heat pumps and solar panels; HMRC names secondary and double glazing as excluded (VAT Notice 708/6). The Energy Saving Trust confirms that homes with electric heating and good insulation see the strongest savings on Economy 7 (energysavingtrust.org.uk).
| Item | Figure |
|---|---|
| Upfront cost after grants | £800 |
| Yearly savings | £290 |
| Payback period | 2.8 years |
| 25-year lifetime savings | £6,450 |
What homeowners often get wrong
The most common mistake is assuming Economy 7 automatically saves money because the off-peak rate is lower. Three frequent errors cost households real cash.
- Ignoring the on-peak penalty Many people focus only on the low night rate and forget that daytime electricity jumps to around 30p/kWh. If you use less than 40% of your total electricity overnight, you end up paying £100 to £200 more per year than on a standard single-rate tariff.
- Running gas central heating on Economy 7 Some households keep their gas boiler for heating but switch to Economy 7 for general electricity. This rarely works because gas heating uses very little electricity, so you cannot shift enough load to the off-peak window. You waste £80 to £150 annually on higher day rates with no heating benefit.
- Failing to check night usage before switching Homeowners often switch to Economy 7 without analysing their consumption patterns. Without a smart meter or a full year of two-rate readings, you cannot know your night usage percentage. If it is below 40%, you have no way to reverse the tariff without paying a £25 to £50 exit fee.
Quick reference
- Economy 7 saves money only when at least 40% of your total electricity is used during the seven-hour off-peak period each night.
- The off-peak rate is roughly 14p/kWh compared to a standard single-rate tariff of 24p/kWh, but the on-peak rate jumps to around 30p/kWh.
- You qualify for Economy 7 if you have a two-rate electricity meter or a smart meter that records separate day and night usage.
- Typical annual savings for a household with electric storage heaters and 60% night usage are £250 to £350 against a standard tariff.
- Switching to Economy 7 without checking your night usage first can leave you paying £100 to £200 more per year than necessary.
Frequently Asked Questions
You need at least 40% of your total electricity use during the off-peak window. Ofgem says anything below that means you're likely losing money.
No, for most households. The Energy Saving Trust estimates fewer than one in three households on Economy 7 save money compared to a standard single-rate tariff.
Look at your two-rate meter readings over a full year. If night usage is below 40% of total, switch to a standard tariff. GOV.UK recommends a free smart meter for accurate data.
