Combining Batteries and Other High Power Services in an Energy Hub : Mathematical Optimization Model and Case Study

Sammanfattning

Society is moving to reduce carbon emissions. This transition has led to both increasing amounts of renewable energy in the power system and to the continued electrification of society. This new reality is presenting new challenges in maintaining power system stability and developing infrastructure to support these changes. In this thesis, the operations of an energy hub consisting of a Battery Energy Storage System as well as a charging station for electric vehicles is explored. The hub can participate in ancillary services to support frequency regulation and support a charging station for electric vehicles. A mathematical optimization model is constructed to determine the optimal operations of the energy hub by maximizing profit through participating in primary control frequency regulation ancillary services and selling power through charging electric vehicles. The model describes the charging and discharging of the battery, the relationship between all the power flows of the problem and other relevant limitations in a mixed integer linear problem. The optimization problem is solved using the open source Python package Pyomo with the solver GLPK, to simplify future extensions to the work. A case study is performed based on data provided by Creek Power AB, and simulations based on this data indicate that the operations are very dependent on the remuneration price for the various services, as well as the electricity spot price. By balancing the usage of the battery, the solution ensures reliable supply of power to the electric vehicle charging station, while maximizing the profit gained by participating in the ancillary services. The simulations show that the operations of the energy hub are profitable. However, further simulations with varying parameter values are necessary to draw final conclusions on the optimal setup of such an energy hub.