California is using 20.1 GW of electricity right now.

The California Independent System Operator (CAISO, or California ISO) is the nonprofit that runs the high-voltage grid and wholesale power market serving about 80% of California's electricity demand, some 32 million consumers. It owns no power plants or power lines. It dispatches the plants and directs the flow of power over the lines, keeping supply and demand matched moment to moment. Los Angeles, Sacramento, the Imperial Irrigation District and Turlock run their own grids, which trade power with CAISO's.

At 7:35 a.m. on November 14, renewables were meeting 71% of grid load (demand plus battery charging) on CAISO's grid. Over all of November 13 they met 35%. CAISO counts solar, wind, geothermal, biomass, biogas and small hydro as renewable; large hydro and nuclear make no direct emissions but are counted separately. State law requires 60% of retail electricity sales to be renewable by 2030 and sets a goal of 100% renewable and zero-carbon electricity by 2045.

California's electricity is usually cleanest around midday, when solar carries the grid, and dirtiest after dark, when natural gas and imports fill in. On November 13, carbon intensity on CAISO's grid averaged 192 kg CO₂/MWh, from 107 kg at 9:35 a.m. to 297 kg at 4:25 a.m. At 7:35 a.m. on November 14 it was 70 kg. CAISO counts direct emissions from power plants and imports, credits exports, and divides by grid load.

Wholesale prices fall below zero when solar and wind make more power than the grid can use, store or send to neighboring grids, most often on spring middays. Some generators would rather pay than stop: a gas plant that shuts down pays to restart, and some wind and solar farms earn a tax credit for every megawatt-hour they deliver. On November 14, the price at the SP15 hub in Southern California had not gone below zero by 7:35 a.m.; its low was $18.33/MWh at 7:35 a.m. Household rates are set separately and don't follow these five-minute prices.

The duck curve is the shape electricity demand takes over a day once solar and wind output is subtracted, a measure grid operators call net demand. It sags at midday as solar peaks, the duck's belly, then rises steeply into the evening as the sun sets, its neck. It takes its name from a 2013 California ISO chart that projected the curve out to 2020. On November 13, net demand on CAISO's grid had its midday low of 5.6 GW at 9:40 a.m., then peaked at 22.5 GW at 6:30 p.m.

Batteries charge in the middle of the day, when solar power is plentiful and cheap, and give the energy back as solar fades and demand peaks in the evening. On November 13, batteries on CAISO's grid stored 46.0 GWh and released 37.5 GWh. At their peak, 6.8 GW at 6:15 p.m., they were covering 26% of supply.

Most of California's imported power comes from two directions: the Pacific Northwest, much of it hydropower, and the desert Southwest, including plants in Arizona and Utah that California utilities partly own. Some of what CAISO counts as imports comes from grids inside the state, such as those of Los Angeles and Sacramento. At 7:35 a.m. on November 14, CAISO's grid was a net exporter, sending 0.7 GW to neighboring grids; it had been exporting since 7:25 a.m.

Demand on CAISO's grid is highest on hot late-summer afternoons and early evenings, when air conditioners run hardest. The all-time high is 52.1 GW, set on September 6, 2022. The forecast for November 14 put the day's peak at 24.3 GW around 5:40 p.m.