Increasing the value of offshore wind by integrating on-board energy storage

Abstract

Energy storage technologies are considered a promising solution for overcoming one of the most pertinent hurdles to high renewable energy penetration: the mismatch between energy supply and consumer demand. The intermittent nature of variable renewable energy technologies at high penetration rates leads to a loss of value for each unit of energy produced. Generationside energy storage can allow wind turbines to alter their generation strategies and derive additional value through improved market participation. On-board storage leads to more efficient use of space and a potential for cost reductions. In the present work, a brief review of existing work on these aspects was undertaken, followed by a time-series analysis of an offshore 6 MW wind turbine coupled to an energy storage system. The performance of the wind+storage system was simulated using one year of data from the Egmond aan Zee offshore wind farm site. A statistical analysis was undertaken to estimate the required charge/discharge cycles and establish the required storage capacity under different operating conditions. A lithium-ion battery was then considered as the competing energy storage technology, and a cumulative damage model was applied based on the depth-of-discharge characteristics. Findings indicate that despite their competitive capital costs, battery technologies would have a limited lifetime resulting from high charging/discharging cycles. A more viable approach in the long-term could be to opt for technologies that are less dependent on charge/discharge cycles and which have a lifetime that can match that of the wind turbine itself.