USA, California: California’s power system is changing rapidly as solar generation and large-scale battery storage take a growing role in grid operations, while utilities continue investing in transmission, substations and distribution infrastructure.
Carbon-free sources, including solar, wind, hydro, geothermal and nuclear, supplied 62 % of California’s electricity in 2024, up from 58 % a year earlier. Solar alone accounted for 20 %, compared with 8 % a decade ago.
The biggest operational change has come from battery storage. California now has around 21,000 MW of battery capacity, compared with only a fraction of that level five years ago. Batteries store surplus solar generation during the day and discharge it after sunset, when solar output falls and electricity demand rises.
According to CAISO, batteries now provide more than 60 % of the power needed to cover the evening demand surge during hot months. Natural gas plants, however, remain important during periods of prolonged heat, low renewable output and other grid emergencies.
Rapid renewable growth is also increasing the need for grid reinforcement and new infrastructure. Utilities have invested heavily in transmission lines, substations, poles and wires, as well as measures to improve wildfire resilience.
Demand is expected to rise further through electric vehicles, building electrification and AI data centres. California already hosts more than 200 data centres, and electricity demand from these facilities is forecast to more than quadruple by 2040.
The combination of renewable generation, storage and new high-demand loads is changing both how California operates its grid and where future infrastructure investment will be required.
Source: KQED
