Renewable energy system sizing with power generation and storage functions accounting for its optimized activity on multiple electricity markets

With increasing deployment of offshore wind farms, energy storage systems (ESS) are necessary to balance the renewable energy’s intermittency. Instead of independently sizing ESS for an existing renewable energy system (RES), this research highlights the importance of simultaneously sizing all subsystems of an RES. With specific electricity markets in mind and the offshore transmission cable power capacity as a constraint, a model predictive control algorithm is used to maximize the revenue streams for the studied RES. Results demonstrate how the choice of financial metric plays a key role in the outcome: using the levelized cost of energy yields a differently sized RES compared to using the net present value (NPV). In terms of the latter, including a sized ESS in an existing RES increases the NPV significantly. Simultaneously sizing all subsystems of the RES, on the other hand, shows that a 50% increase in NPV can be achieved by deploying a smaller generation subsystem with a larger power capacity ESS, compared to the case in which only the ESS is sized. The introduced sizing approach can be utilized before deploying RES to take their context of operation into account, thereby avoiding the design of suboptimal solutions.