Energy storage technologies from a power system point of view

Abstract

This thesis presents energy storage technologies, as well as their most applicable ways of integration into the power system. The storage technologies provided are relevant in regards to ancillary services, peak shaving, energy arbitrage and not least integration in combination with intermittent renewable production. A grid analysis was performed to determine the obvious differences between different place- ments of the storage system ranging from behind the meter to feeding transformer of the radial. The analyses are static of nature and is included to exhibit power flow, voltage stabil- ity and load percentage of the transformers. Dynamic analyses are not included due to time constraints. The grid simulations were performed in the software NetBas. The results of the simulation concur with most previous studies in the field that behind the meter placement is the most optimal. In addition to placing the storage as far downstream the power system as possible, it is important that local consumption plays a deciding factor concerning the placement of the ESS. The economic feasibility of energy storage integration is outside the scope of the thesis project, but it is suggested that it will increase as battery prices decrease. Considerations are also made on the future smart grids. Smart grids will increase distrib- uted energy generation with wind and residential solar power. A possible solution to this is presented throughout the thesis as distributed energy storage. This has the potential to assist the existing ancillary services as well as allow further increase the penetration of distributed energy generation.