In order to encourage solar installation owners to increase their self-consumption, a variety of manufacturers have developed and are now offering special heating elements that consist of a solar battery and a heat collector, which allow users to heat up and boil water using solar power.
Recent developments have made it possible to use solar power to boil water. Most new buildings already use this grassroots technology to produce hot drinking water. Some even induce it directly into the water buffer by using a single- or three-phase heating element. These developments make green energy only stronger in the competition with combustion energies.
An easier and safer solution
The new ways of electrically producing boiled water make it easier for customers to gain hot water in an environmentally friendly way and are relief for architects and building experts. After all, on average, at least in Germany every household uses up to 120 litres of water per day, and a third of it is heated.
Moreover, heating the water electrically is a much safer procedure, as gas tanks are prone for polluting the home’s air or even exploding. As a plus, it helps reducing costs as well: Unlike with gas tanks, by using electricity to heat water it becomes unnecessary to heat a boiler up to almost 1000 degrees merely to warm the water slightly.
Efficient and economic technology
But how does it work? The heating blade is inserted in the water tank, where it converts unused solar power to heat and thus warms the water. Once this has happenend, the blade switches off automatically and the remaining heat can be used for other purposes. Single-phase heating elements normally have a capacity of up to three kilowatts, while three-phase models go up to nine kilowatts.
Bacteria protection: the disadvantage
There is only one downside of this system: a water reservoir is required, which allows the heat to be transferred into the drinking water. These kinds of reservoirs or tanks, however, make it easy for bacteria, especially Legionella, to settle and multiply. As a result, reservoir owners are encouraged to heat the water in their tanks regularly to 70 degrees, which kills these bacteria. But not only is this costly, it is also hotter than the water temperature that is usually required by a household. To cool it back down, cold water needs to be added, which wastes both energy and water.
Generally, electrical water-heating systems require only very little maintenance. However, lime can easily damage them, which is why regular descaling and / or the use of filter cartridges are highly recommended. Also, it is important to make sure the drinking water and the water for heating do not mix to avoid contamination.