As a result of the modifications in the energy supply towards renewable energy, new challenges will arise considering the stability of grids . Sooner or later, the adjustment of conventional power plants itself will not be able to compensate supply fluctuations caused by irregular electricity generation such as photovoltaic energy or wind power. To compensate these fluctuations, energy storage will become more and more important.

Currently, pumped-storage hydropower plants are globally by far the most used type of electrical energy storage. Nevertheless, due to geological circumstances, the potential for new construction projects is limited in Germany. Considering a European solution, the expansion of grids would also be urgently required, for example to use pump storages in Norway to supply electricity customers in southern Germany.

Important questions will be:

• What are the storage technologies of the future?

• How large is the demand for storage capacity?

• Can energy storages be operated cost-effectively?

• What is the grid capacity?

• How can electric vehicles be implemented into an integrated concept?