Options for an autarkic operation of a communal power grid using a battery and renewable energies

With a growing share of renewable energy, the structure of the electrical power grid structure should reflect their distributed nature. A cellular grid structure would meet this demand. In case of global blackout each cell would even be able to operate autarkic. Then, still a minimum level of supply would be possible. An innovative community in the north of Germany aims to pursue such a concept. The local energy provider, Versorgungsbetriebe Bordesholm, is planning to install a large battery (12 MWh / +/ 8 MW) to provide control power during daily operation. In case of a global blackout it should supply the community in combination with available energy sources. However, the supply consisting of two biogas generators with 800 kW each and several photovoltaic systems are not sufficient for an infinite autarkic supply. Therefore, this publication investigates the possible operation time for such an autarkic operation. Typical self-supply times for this community range from 3 to 20 hours.