September 1st, 2010 by Shaun Day

Economy 7 is a tariff provided by some UK electricity suppliers. Simply put, during the day (usually from 7am until midnight) your electricity costs slightly more than the standard rate. However for 7 hours every night, your electricity rate is around a third of the standard rate. To get Economy 7 you have to have a special meter installed that supplies electricity at the cheaper rate during the off-peak hours. Any appliances that you use during off-peak hours need to be plugged into this system. There’s no point having an Economy 7 tariff if you don’t change your electricity usage habits. To get the most out of Economy 7 you need appliances that work during the off-peak hours to get the most of out of the cheaper rate at these times. Some appliances, such as washing machines, can come with or be fitted with timers so that you can set them to turn on after midnight. When it comes to heating your house with an Economy 7 tariff, the best way to make the most out of it is with a decent storage heater. A storage heater is a fairly simple type of electric radiator that is designed to store heat during off-peak hours and then release it at a time of your choosing. For those interested in the science: Storage heaters usually contain ceramic bricks with a high specific heat capacity to store heat. Specific heat capacity is a unit measurement of how much heat energy a material can store in a given mass. Materials like ceramic bricks have a high specific heat capacity and can therefore store a lot of heat energy in a small volume. This is important because it means that a lot of energy can be stored in the storage heater at a safe temperature, meaning that it will be able to release heat into your home for a long enough time to last until the next off-peak period. Economy 7 isn’t for everyone; if your house is already fitted with gas central heating then it probably isn’t worth changing your appliances and getting it installed. However if you are using electric heating already and finding your utility bills are costing more than you’d like, it’s definitely worth thinking about. If you already have Economy 7 and you don’t have a storage heater, then I’d highly recommend looking into getting one. You aren’t making the most out of your tariff if you don’t!