With storage heaters, electric energy is converted at night into thermal energy, stored and emitted to the air as convection heat via fans the next day. The storage entails losses of around 10% through unwanted radiation. Much higher losses arise on account of the countercyclical operation. This means the charging at night is based on the temperature prevailing at the time of charging. The temperature on the following day, however, can be too high or too low for the charging. Too little or too much thermal energy is stored. This in turn causes a discharge of the stored heat if the daytime temperature is higher that has to be dissipated by opening the windows. Given low daytime temperatures, additional heating generated by expensive daytime electricity via a little efficient system is needed.
Night storage heaters boomed in the 50s and 60s of last century. This type of heating was a welcome alternative to coal and oil furnaces that impeded the living quality in a house due to dirt and smells and were associated with some effort and hazards. By contrast, storage heaters were seen as clean, easy to handle and very trendy. In addition, customers were lured with cheap overnight rates and large-scale subsidy programmes. For the operators of oil, gas and coal power plants it meant balanced utilisation and an optimisation of results.
Prohibition of storage heating:
According to the Energy Saving Regulation (EnEV), all night-storage heaters installed before 1990 are permitted only until the end of 2019. All devices connected since 1990 are allowed to run a maximum of 30 years. This prohibition is to be maintained despite the demand on the part of RWE to use the devices for ecological energy storage. (This prohibition applies only in Germany at present.)
- Heating cost savings of up to 50% are possible.
- An immense gain in comfort and well-being
- No operating costs for service and maintenance
- No health concerns because the heaters are free of asbestos, mineral fibre & heavy metals
- More space in your home
- No more dust and dry air
- No damp walls and no mould
- Significantly better ecological balance