California ISO Greenlights Transmission Plan for Offshore Wind Integration

Grid Connection

May 24, 2024, by Adnan Memija

The California Independent System Operator (CAISO) has approved the 2023-2024 Transmission Plan that identifies and plans for key upgrades to California’s transmission system to deliver power from offshore wind turbines to the state’s homes and businesses.

CAISO unveiled its draft 2023-2024 Transmission Plan last month which identifies a need to invest in 26 transmission infrastructure projects in California, including several projects on the state’s North Coast that will upgrade grid capacity to integrate power from offshore wind projects off the coast of Humboldt into the California grid.

Specific projects included in the plan, most notably to integrate offshore wind from the North Coast, are a new Humboldt 500 kV substation complete with a 500/115 kV transformer; a new HVDC line (approx. 260 miles) to interconnect the new Humboldt substation to the Collinsville 500 kV substation; and new 500 kV AC line (approx. 140 miles) to interconnect the new Humboldt substation to the Fern Road 500 kV substation.

The plan also involves a 115 kV line from the new Humboldt line to the existing Humboldt 115 kV substation, and a 115 kV phase-shifting transformer at the Humboldt 115 kV substation; and a host of smaller upgrades improving the supply of load and access to other smaller resource areas.

When it comes to offshore wind, the plan allows for over 4.7 GW of new offshore wind capacity with 3.1 GW in the Central Coast (Morro Bay call area) and 1.6 GW in the North Coast area ( Humboldt call area).

California initially planned to install 3 GW of offshore wind by 2030, 15 GW by 2045, and 20 GW by 2050.

However, in 2022, the state increased its targets and set a goal of 25 GW of installed offshore wind capacity by 2045.