The California Independent System Operator is proposing $6.1 billion in transmission projects, mainly to help deliver offshore wind to customers, according to a draft transmission plan released Monday.
Transmission projects to access clean energy resources total about $4.6 billion and are all in Pacific Gas & Electric’s service territory. Reliability-driven projects total about $1.5 billion.
Two projects in northern California — costing an estimated $2.7 billion and $1.4 billion — would be open to competitive bidding, according to the draft plan.
The plan is based on projections that California will need to add more than 85 GW by 2035 to meet its clean energy goals. The grid operator expects the projects, if approved, will be built over the next eight to 10 years.
CAISO said the draft plan will provide access to more than 38 GW of new solar, including in Nevada and Arizona, as well as 21 GW of geothermal capacity, mainly in the Imperial Valley and southern Nevada.
The plan would also allow more than 5.6 GW of wind imports from Idaho, Wyoming and New Mexico and more than 4.7 GW of offshore wind off the state’s northern coast.
CAISO said while developing its transmission plan it reviewed the proposed Pacific Transmission Expansion project — a 500-kV high-voltage, direct current project from the Diablo Canyon 500-kV substation to 230-kV substations in the Los Angeles Basin.
However, it didn’t include the project in the proposed plan because the Los Angeles Department of Water and Power hasn’t made a decision on whether it wants to pursue it, CAISO said.
The project could provide access to offshore wind, relieve congestion on Path 26 and reduce LADWP’s gas-fired generation needs. “The ISO will continue to explore gas-fired generation retirement plans with the [California Public Utilities Commission] and work with LADWP on potential collaborations in the next planning cycle,” the grid operator said.
As it has in previous planning cycles, CAISO considered using grid-enhancing technologies to improve the existing transmission system. The proposal includes a phase-shifting transformer to provide flow control to bolster grid resilience in northern California.
The draft plan is slated to be discussed at an April 9 meeting and could be voted on by CAISO’s board in May. The board approved $7.3 billion in transmission projects last year.
The draft plan was developed in close coordination with the CPUC and the California Energy Commission, according to CAISO.
As part of an agreement between the agencies, CAISO will develop a final transmission plan, initiate the transmission projects and tell the power sector which geographic zones are being targeted for transmission projects along with how much capacity will be available in those zones, the grid operator said.
The CPUC will then direct load-serving entities to focus their energy procurement on those transmission zones and CAISO will give greater priority to interconnection requests in those zones, the grid operator said.
Editor's note: This story has been updated with a map of CAISO's proposed transmission plan.
