Economy 7 is an electricity tariff that charges two unit rates across the day, a cheaper rate for seven off-peak night hours and a dearer rate during the day. It suits homes that can shift consumption, such as storage heating, into the night period.
In one line: Economy 7 is a two-rate electricity tariff offering cheaper power for seven night hours and a higher rate by day.
How Economy 7 works
The meter records day and night usage separately, and the supplier applies the relevant unit rate to each. The exact seven-hour off-peak window varies by region and meter, typically falling overnight.
If night usage is 200 kWh at 15p and day usage is 150 kWh at 30p, the bill is 30 GBP plus 45 GBP, totalling 75 GBP before the standing charge. Shifting more load to nights lowers the total.
Economy 7 only saves money where enough consumption can move into the cheaper window, because the daytime rate is usually higher than a standard single-rate tariff.
Economy 7 vs a single-rate tariff
A single-rate tariff charges one unit rate at all hours, while Economy 7 splits the day into a cheap night rate and a pricier day rate measured on a two-register meter.
Economy 7 favours households with electric storage heaters or overnight loads, whereas mostly daytime users typically pay more under it than on a flat rate.
Primary source: Ofgem: Get help with energy