Renewables have priority in Germany’s power grid. However, the growing share of renewable energy and the resulting frequency fluctuations mean grid operators are increasingly implementing so-called curtailment measures. This often involves requiring wind turbines to shut down temporarily. In 2016, 335 GWh of solar and wind power was curtailed in Brandenburg, the federal state surrounding Berlin. That would be enough to power Berlin for 10 days. Such measures are expensive and potential generation from clean sources goes unrealized. Sector coupling and demand-side management are two solutions, alongside energy storage and grid expansion.
One such technology, power-to-heat (P2H), is increasingly common in Germany. However, a project carried out by GASAG Solution Plus has combined P2H with power-to-cool (P2C) technology and integrated it into the balancing energy market to offer a new storage solution. The system, which the company claims is the first of its kind in Germany, is based at Berlin’s EUREF Campus and was opened on Friday October 13th by the Berlin Senator Ramona Pop.
The P2H/P2C system consists of two 22-cubic-meter storage tanks and a 550 kWel electric heater which uses excess power to heat water. This can then be fed into the EUREF campus’ heating network as required. Two compression chillers provide local cooling according to the same principle, which enables excess electricity to be stored in summer when heating requirements are lower. A biomethane CHP unit is used to compensate should the mains frequency be too low. The system thus makes a valuable contribution to improving grid stability through the novel combination of existing technologies.
The P2H/P2C plant forms part of the emerging “energy workshop” project at the EUREF Campus within the WindNODE initiative, which in turn is part of the German Federal Ministry for Economic Affairs and Energy’s SINTEG program.
- GASAG: Press release (in German)