This utility or commercial application example shows the use of supercapacitors alone or combined with li-ion batteries for solar output firming, protecting li-ion batteries, or control optimization. Supercapacitors help fill voltage dropouts and absorb spikes. A battery-only system offers short life and lower capacity compared to a supercapacitor or supercapacitor plus battery system, which offers a significantly longer lifespan of up to twenty years and higher power output to meet utility ramp rate control requirements.