On August 24, 2021, the U.S. Energy Information Administration (EIA) reported on its website that the amount of1 output curtailment of utility-scale solar power is increasing in the western U.S. state of California. Within the California Independent System Operator (CAISO), which is responsible for approximately 80% of the state's electricity supply, 1,500 GWh, or 5% of the annual available solar power generation, was curtailed in the year 2020 to maintain the balance between electricity supply and demand and to relieve transmission line congestion. This paper outlines the trends related to solar output curtailment in the state and CAISO's efforts to avoid renewable energy output curtailment.