How off-peak energy works
Storage heaters use off-peak electricity which is supplied from the national grid to your house, usually overnight when demand for electricity nationally is low. This is called the ‘off-peak’ period
Because it’s off peak, it’s supplied at a cheaper price than standard rate electricity, so it needs a separate off-peak electrical circuit and meter. This circuit is dedicated to operating the off-peak heaters and is only switched on during the off-peak time period. This will take place at certain times of the day or night, and will be dictated by your electricity supplier.
In the same way that your kettle uses an element to heat water, electricity is used to heat elements in your heater. Over a number of hours, the elements gradually transfer the heat to a very high-density material that absorbs and stores the heat for use the next day. The off-peak heaters use insulation material to retain as much of this heat for as long as possible.
When the off-peak period finishes, for the majority of off-peak heaters, the heat is gradually released into the room in a controlled way over the course of the day. In the case of smart fan-assisted models such as Quantum almost all of the heat is retained until it is required.
Off-peak storage heaters
Off-peak heaters, such as Quantum and storage heaters, are electric heaters designed specifically to operate using cheaper, off-peak electricity and, as the name implies, store heat until it is required. There are four types of heater, each offering different levels of comfort control:
1) Manual control models require the user to manually set the amount of energy that should be stored overnight. These models have been phased out for new models with more advanced controls.
2) Automatic models, such as the XLSN, automatically adjust the overnight charge based on the room temperature and therefore are more efficient than manual models.
3) Combination models, like the CXLS, store off-peak energy in the core overnight in the same way as the automatic models and in addition to this they can top this up in the day time using the peak rate energy if required. Models like the Duo heat have a radiant front panel and more advanced controls.
4) High heat retention storage heaters such as Quantum have smart controls that take exactly the correct amount of charge. They have a highly insulated core so therefore have a fan to extract the heat when it is required and a direct acting element to provide extra heat during the day time if required.