The share of electricity from photovoltaics in the electricity mix in Germany has been greatly expanded in recent years. In the near future, electricity generation from renewable energies and thus also solar generated electricity will continue to increase. At high solar radiation, this already leads to a local oversupply in the power grid, while the photovoltaic at night naturally can not contribute to the power supply. Ensuring the nightly base load at night is therefore largely ensured by fossil production from coal and lignite with corresponding CO2 emissions.

By using base load storage systems with low-temperature storage, the use of polluting thermal power plants should be reduced. During the day, heat from geothermal energy or industrial processes is upgraded with excess electricity from photovoltaics using heat pumps (HP) and stored in a low-temperature storage system. To generate nocturnal base load power, this heat energy is then removed from the storage via an Organic Rankine Cycle (ORC) process.

The aim of the project is the dynamic simulation of energy flows in HP-ORC heat storages that are integrated into the energy system and use excess heat and power. With the simulation models, the dimensioning and suitable operating modes for the economic operation of low-temperature storage systems should be investigated.