What's an Economy 7 or an Economy 10 (White Heat or Heatwise) meter?
An Economy 7 meter is a two rate meter (with day and night registers). The night rate is a seven-hour period (usually midnight to 7 am) that is charged at a lower rate than the day rate. They’re most suitable for people with storage heaters and a hot water tank, which can be heated up at night and then used to provide hot water and heating the following day.
An Economy 10 meter offers ten hours of off-peak electricity at a lower rate, seven days a week. Economy 10 meters are also suited to members who have storage heating at their property or use a large amount of electricity during off-peak hours. The Economy 10 rate usually takes effect for three hours in the afternoon, two hours in the evening and five hours overnight.