Future developments of the photovoltaic technologies in Germany and their consequences in the power network stability, the system security and the demand of chemical long-term storage

The Energy Transition in Germany fosters significant changes not only on the requirements for transmission networks but mainly in the conditions of the electricity distribution grids as well. These grids must not only distribute electricity to the consumer anymore. They must also be able to handle and transport more and more decentralized electricity generated in photovoltaic systems. The planned expansion of the photovoltaic systems until 2050 (when there is the target to supply 80% of the German electricity with renewable energy sources) is a key driver for the expansion of the networks and storage technologies, as this energy will be predominantly connected to the distribution network. By the end of 2013, 35GW of electricity generated from solar technologies (corresponding to 100%) were connected to the electricity distribution network. As part of the energy transition the construction of additional facilities will increase significantly. That means that the capacity of the distribution network will not be enough anymore to transport the surplus electricity generated from renewable energies. For this reason, storage technologies must be purposefully used to optimize the network operation. By using chemical long-term storage (power to gas) it could be possible to achieve a significant load removal and with it, a reduction in the net expansion demand [1, 2].