In the control area of the German transmission system operator (TSO) and TSCNET shareholder 50Hertz in northern and eastern Germany, the installed renewable energy capacity is particularly high. Often it is necessary to take wind turbines off the grid and compensate the operators for the losses. Some of this green excess power is to be used more efficiently in the future: Together with Stadtwerke Rostock, the public utility company of the Baltic port city, 50Hertz is planning the construction of a Power-to-Heat (PtH) plant to use this energy cross-sectorally for the heat supply of Rostock.
The projected electrical output of the plant is 20MW and construction is scheduled to begin this year. The PtH plant will be combined with the thermal energy storage unit yet to be built on the same site. Stadtwerke Rostock is responsible for the design, construction and operation of the PtH plant. 50Hertz bears the investment costs of around €20m and also ensures that the facility will appropriately be involved in eliminating bottlenecks in the TSO’s extra-high voltage grid.
For 50Hertz, the PtH plant is a further step on the way to fully integrating the increasing amount of electricity from onshore and offshore wind farms into the power system in a safe and cost-effective manner. Dr. Dirk Biermann, Chief Markets & System Operations Officer at 50Hertz, explains: “Economically and ecologically, the motto must be: ‘Using instead of throttling down’. The conversion of green electricity into thermal energy for heating or hot water supply is a reasonable alternative to shutting down, thus utilising renewable resources even when there are bottlenecks in the electricity transmission grid.”