Integrating Hybrid Energy Storage System on a Wind Generator to enhance grid safety and stability: A Levelized Cost of Electricity analysis

Abstract New stringent environmental policies entail a fast-growing energy demand from renewable energy sources to date. Wind and solar energy sources currently represent the most widespread renewable sources, although they have an intermittent and fluctuating behavior. Therefore, they are classified as non-programmable sources and can negatively affect grid stability and safety. To overcome this issue, a possible solution can be the integration of energy storage systems to renewable generators. Specially, hybridizing flywheel and battery technologies and implementing smart power management systems, power profile fluctuations at the point of interface to the grid are reduced by more than 80% compared to the wind profile. In this paper, an economic analysis of a 2 MW wind generator coupled to hybrid energy storage systems, constituted by a flywheel and a lithium-ion battery, coupled to a 2 MW wind generator is assessed in terms of LCOE of the plant. Simulations show how the employment of a hybrid storage system results economically competitive with respect to the case of wind turbine without storage unit. LCOE values inherent to the case of wind generator with hybrid storage system integration have been also assessed considering the remuneration of ancillary functions. In this case a LCOE reduction over 5%, with respect to the case of energy storage absence, can be achieved if NMC battery technology coupled to mechanical flywheel is installed considering the remuneration of the “Fast Reserve” service as regulated by the Italian TSO. The resulting analysis provides a significant economic feedback aiming to accelerate and increase wind energy production in Italy.