Electric Storage Heaters - Can You Save?
Friday, July 17th, 2009Electric Storage Heaters are electrical appliances which stores heat at a time when base load electricity is available at a low price, usually during the night, and releases it during the day. Heat is usually stored in clays or other ceramic material because of its low cost and high specific heat capacity.
Storage heaters are usually used in conjunction with a two-tariff electricity meter which records separately the electricity used during the off-peak period so that it can be billed at a lower rate.
In order to derive any benefit from a storage heater, the house must be on a special electricity tariff. In the United Kingdom, the Economy 7 tariff is appropriate. This is the name of a tariff provided by United Kingdom electricity suppliers that uses base load generation to provide cheap night-time electricity.
Storage heaters usually have two controls - a charge control (often called “input”), which controls the amount of heat stored, and the draught control (often called “output”), which controls the rate at which heat is released. These controls may be set by the user, or in some models are automatic and allow you to set the target room temperature using a thermostat.
Many units also contain a conventional electric heater which can be used to give a boost in heat output during the day. If this feature is relied upon too much, a lot of peak time electricity will be used and the storage heater will prove expensive to run.
Storage heaters have several drawbacks:
* If insufficient heat has been stored, for example if there is an unexpected period of cold weather, then any extra heat needed will have to be produced using full-price electricity.
* If too much heat has been stored, then sooner or later the heat will be released into the room whether it is needed or not.
* Storage heaters are very heavy and somewhat bulky, due to the material used to store heat.
* Unless the heater is of the modern well-insulated type, heat is leaked out whenever the bricks are hot, meaning that having a room warm in the evening requires it to be warm all day (albeit probably at a lower setting), wasting energy (unless the room is in use all day as well). However, the consequences of this energy loss are often more than compensated for by the heater’s use of an off-peak base load that is effectively “spare energy” and is cheap.
* They can be wasteful If the user is only at home for part of they day or suddenly decides to spend most/all day away from home.
