Solar PV and Battery Systems In Sweden: An investigation of the frequency ancillary market for batteries

Abstract

Abstract The aim of this thesis was to evaluate the possibilities of tackling the constant changes in the market for frequency ancillary services from batteries, both from a short and long-term perspective. The short-term perspective focused on the possibilities of combining supplying FCR-D to the grid with increasing self-consumption of electricity from solar PV in private homes. This was done in two steps, first historical frequency disturbances were investigated to evaluate the possibilities of increasing the use of batteries thst provide FCR-D. The seond step was done by implementing an algorithm for battery operation that combined FCR-D with increasing self-consumption that was tested on real customer data. The long-term perspective instead focused on service development processes for companies in aggregator positions to give recommendation on how to continuously work with service development to be ready for sudden changes in the market. The result for the short-term perspective showed that 99.7% of disturbances are below five minutes in duration and batteries providing FCR-D never reach any critical levels of not being able to deliver FCR-D during a disturbance. Further, the results from simulating combinations of providing FCR-D and increasing self-consumption showed that a simultaneous operation yielded the highest self-consumption. Using 34% of inverter capacity which had been reserved for recharging gave the highest self-consumption result. Recommendations in the long-term perspective include maintaining close customer relationships and involving them in the service development process, as well as investing in market sensing and structured service development.