Technologies like green hydrogen, advanced compressed air, and pumped hydro storage are becoming essential for achieving 100% renewable electricity systems, with deployment accelerating toward the 970 GW global target by 2030. The AES Lawai Solar Project in Kauai, Hawaii has a 100 megawatt-hour battery energy storage system paired with a solar photovoltaic system. Sometimes two is better than one. The reason: Solar energy is not always produced at the time. How much energy storage is suitable for photovoltaic power generation? Determining the optimal energy storage capacity for photovoltaic power generation hinges on several critical factors, including 1. the local solar production potential, 2. National Renewable Energy Laboratory, Sandia National Laboratory, SunSpec Alliance, and the SunShot National Laboratory Multiyear Partnership (SuNLaMP) PV O&M Best Practices.