OPPORTUNITIES FOR BATTERY ENERGY STORAGE IN STAND-ALONE AND CO-LOCATED HYBRID POWER PLANT IN DISTRIBUTION GRID

An emerging approach for effective grid integration of renewable energy sources (RES) involves hybridizing one or two types of RES with battery energy storage (BES). A BES in such a hybrid power plant (HPP) allows for maximizing generation and profitability while offering ancillary services to the grid. Various grid operators around the world are also exploring stand-alone BES with the goal of avoiding grid reinforcements and boosting the capacity of existing network assets such as transmission lines. However, it is unclear if an HPP with BES has leverage over a stand-alone BESS, or vice versa, from the perspective of the network operator with the objective of maintaining steady state operating conditions in the grid and boosting the hosting capacity. This research aims to analyze and compare the active and reactive power benefits offered by BES as a part of a co-located HPP and a stand-alone system. A 48-bus medium voltage Danish distribution grid model is used as a test system. Improving grid operating conditions is considered the principal focus of the stand-alone BES and HPP by reducing line congestion, active power loss, and maintaining voltage profiles. The HPP configuration also aims to maximize power generation considering the economic profit of the generator by balancing generation revenue against the cost of fatigue damage for the HPP operator/owner. The two cases are compared concerning the optimization objective to reduce active power loss and battery degradation during the simulated time from the perspective of the distribution grid. A comparison of the two scenarios presented highlights the benefits of a BESS as a part of a co-located HPP and a stand-alone system to provide active as well as reactive power flexibility to the distribution grid.