The California Independent System Operator (CAISO) is a non-profit, public benefit corporation that manages the flow of electricity across the high-voltage, long-distance power lines that make up 80 percent of California's and a small part of Nevada's grid. CAISO is one of the largest ISOs in the world, delivering 300 million megawatt-hours of electricity each year. The organization was created by the California Legislature in 1998 as part of the state's restructuring of electricity markets, responding to Federal Energy Regulatory Commission (FERC) recommendations. FERC regulates CAISO because interstate transmission lines fall under the jurisdiction of federal commerce laws. CAISO's headquarters are located in Folsom, California.
CAISO operates a competitive wholesale energy market, designed to promote lower costs and renewable resources, and conducts transmission planning to identify grid expansion needs and ensure reliability. This involves managing the wholesale electricity transmission system, developing rules for reliable, safe, and equitable transmission, and ensuring that utilities cede operational control of their transmission infrastructure to CAISO. Every five minutes, CAISO forecasts electric demand and dispatches the lowest-cost set of power resources that bid into the market to provide electricity, considering factors like transmission capacity, power plant outages, and extreme weather conditions. The ISO's wholesale energy market includes distinct day-ahead and real-time processes, offering energy products and services to meet reliability needs and serve load. CAISO also operates the Western Energy Imbalance Market (EIM), a real-time bulk power trading market that allows participants across the Western grid to buy and sell energy. The organization is committed to transparency and stakeholder engagement, offering centralized access to information and opportunities to participate in policy initiatives. CAISO plays a significant role in California's transition to clean energy, supporting the state's goals for renewable energy integration. The ISO provides daily reports on California renewable electricity generation.