Hybrid Energy Storage Systems Coupled with Renewable Power Plants for Power Smoothing Applications

The growing renewable generation implies a transition from centralized to de-centralized grid infrastructure, with several low voltage local prosumers taking part as active users within the grid. In this framework, design, planning, modelling, control and optimization of multiple energy systems and grid infrastructures should be developed to manage renewable variability. Therefore, Energy Storage Systems (ESSs) could play a crucial role to provide additional grid flexibility. Grid services, such as power smoothing, load levelling and voltage and frequency sup-port, will play a crucial role to guarantee the safety and stability of future power grids. Nevertheless, single ESS technologies cannot operate over multiple time-scales. To overcome such aspects, implementing different complementary ESSs into Hybrid Energy Storage Systems (HESSs) allows to extend the operating rang-es and the lifespan of the single devices, especially when coupled with very un-predictable renewable generators. Challenging aspects, such as the HESS optimal sizing and power management strategy to maximize the hybridization benefits in power smoothing applications, are analysed in this Chapter. HESS benefits in terms of electric performance at the point of common coupling are also investi-gated. Finally, a techno-economic assessment concerning the benefits of HESS integration for performing wind power smoothing is presented.