Comparative Evaluation of Solar Power Smoothing Techniques Considering Battery Degradation

The intermittent and volatile nature of renewable energy sources (RESs) has introduced new technical challenges that affect the secure and reliable grid operation. These challenges can be tackled at the RES level by reducing power fluctuations with the use of power smoothing (PS) techniques. Several PS methods have been proposed in the literature to smooth RES output exploiting battery energy storage systems (BESSs). However, a comprehensive comparative evaluation of PS methods is missing. Moreover, the effect of the long-term PS operation on the BESS life is usually ignored in such analyses. This article proposes a methodology for the systematic evaluation of well-established PS techniques, comparing their effectiveness on the PS of photovoltaic output based on various signal metrics. In addition, an accurate aging model for lithium-ion batteries is employed to investigate the impact of PS on the BESS lifetime, highlighting the main parameters that influence capacity degradation.