Distributed solar battery systems providing primary control reserve

Abstract

An increasing number of energy storages will be installed in buildings with photovoltaic systems. However, batteries with only local operation tasks do not exhaust their technical potential. Using the available battery capacity in terms of power and energy to provide ancillary system services is therefore economically reasonable. Providing primary control reserve power in combination with increasing local self-sufficiency has been identified as a promising option for decentralised PV battery systems. Thereby, part of the battery capacity is used to provide grid services and the remaining part for the management and optimisation of local system operation. Provision of self-sufficiency increase is limited, when the battery's state of charge is within certain limits. In this study, it is shown that the simultaneous use of the battery to locally increase self-sufficiency reduces the need for external power sources to correct the storage level. The operational concept, the technical solutions, and a sensitivity analysis are presented. Furthermore, billing and measuring issues as well as the current regulatory framework conditions in Germany are discussed.