California’s energy transition requires 53GW of solar PV by 2045, with the state’s transmission system requiring a $30.5 billion investment in addition to a major increase in energy storage to accommodate the additional power. A draft version of California ISO’s (CAISO) 20-Year Transmission Outlook report provides a roadmap for the next twenty years, as well as a draft 2021-2022 Transmission Plan covering the next 10 years. To learn more, read, “California’s energy transition to require 53GW of solar PV, US$30bn+ for grid upgrades by 2045, says CAISO.


Key Takeaways:

  • The report outlined that by 2045, the state would require 53GW of utility-scale solar, 37GW of battery energy storage systems, 4GW of long-duration storage and more than 2GW of geothermal, alongside 24GW of wind power reserves, all of which need to be connected to the grid.
  • Transmission needs will range from high-voltage lines that traverse significant distances to access out-of-state resources with lead times for such upgrades ranging from eight to 10 years being reasonable or optimistic.
  • The CAISO report forecast that the state’s peak load in 2040 would be 82.3GW, up from an estimated 64.1GW in 2030. 
    • CAISO would need to accommodate 73.9GW of this through its network.

Path to 100% Perspective:

The CAISO proposal reveals a sensitivity to seeking geographic diversification through transmission – a critical component to catering to each region’s renewable energy threshold. It falls on the shoulders of every power company to now put strategies and capital in place to navigate to net zero and to embed flexibility at the heart of grids to unlock 100% renewable energy systems. 

The electric grid is expected to be tripled in the coming years – developing the supportive infrastructure to offer a reliable, carbon-free and flexible power system requires proactive solutions to answer the call. Addressing grid capacity will be essential to realizing a 100% zero emission electricity system by 2050, and solar, wind, hydro and nuclear will all play a role in the future grid. The Path to 100% will require leveraging the appropriate technologies and renewable fuels to equip the energy transition.