E.ON launches project unique in Europe to store heat from renewable energy sources

A project that is unique in Europe has been launched in Hamburg by E.ON to feed heat from renewable energy sources into the public district heating grid. Home owners who produce heat with the aid of solar-thermal systems can feed it into the grid of E.ON Hanse Wärme. A customer feeding in heat continues to own it, meaning that he can feed in heat in the summer and then withdraw it again in colder months. This enables home owners to dispense with the need for buying their own storage units for their solar-thermal systems as well as the complex control devices required.

"The combination of point-of-use production and central storage will be an essential element of tomorrow’s energy supply. With this project E.ON is showing that it is already possible not only to feed renewable power into the grid but also heat," said Dr. Dierk Paskert, member of the E.ON Energie Board of Management and Chairman of the E.ON Hanse Supervisory Board.

The Federal Ministry of the Environment is contributing to the funding of this project, which costs seven million euros. The existing heat storage system of a housing estate in the Hamburg district of Bramfeld has a capacity of 4,000 m³. For the purposes of this pilot project it has been converted into a multi-function storage system and integrated into the E.ON district heating grid. E.ON is breaking new ground by feeding solar heat into a district heating grid on this scale.

When it was set up almost 15 years ago, the solar storage system was already the first of its kind in Germany. It has been given a stainless-steel lining and 20 cm thick heat insulation. With its capacity of 4,000 m³ it is unmatched worldwide. Integrating the storage facility into the district heating grid makes it possible to store not only solar heat from the estate but also heat produced in other distributed generation units. The multi-function storage system is connected to E.ON’s district heating grid in the eastern part of Hamburg. E.ON uses this grid to supply up to 400,000 MWh of heat to its customers every year. This meets the heating requirements of about 50,000 single-family homes.