The state must dramatically expand its energy infrastructure and renewable energy sources to satisfy growing demand for electricity while meeting ambitious climate goals, according to California Independent System Operator’s Draft 2022-2023 Transmission Plan.

By Marc Campopiano, Joshua Bledsoe, Julie Miles, and Shawna Strecker

California has committed to ambitious carbon reduction targets and pledged to become carbon neutral no later than 2045.[1] However, to meet these lofty goals while providing reliable energy for millions, the state must commit to an unprecedented degree of renewable power and transmission line development.

The challenge is highlighted by the Draft 2022-2023 Transmission Plan (Draft Transmission Plan) published on April 3, 2023, by the California Independent System Operator (CAISO), the independent energy grid operator that serves approximately 80% of California and a small part of Nevada. As of 2018, California had about 80 gigawatts (GW) of total electric generating capacity.[2] CAISO predicts that California will need to almost double that total capacity in the next decade with new renewable generation and greatly expand the transmission grid in order to achieve clean power targets and vast electrification programs as California attempts to phase out fossil fuel usage. This scale of infrastructure buildout will require unprecedented investments, vastly expedited environmental permitting and review by regulatory agencies, and sustained political will to substantially incentivize and streamline priority projects.

This blog post examines the ambitious roadmap outlined in the Draft Transmission Plan, and CAISO’s long-term transmission planning more broadly, to advance California’s climate goals by undertaking 46 transmission projects and adding at least 40 GW, mostly from renewable sources, to the CAISO grid over the next 10 years.

Draft Transmission Plan aligns with California’s energy planning process

The Draft Transmission Plan details a comprehensive, long-term strategy to ensure that CAISO can deliver reliable and sustainable electricity to millions of Californians. CAISO’s process is intended to align with other statewide planning efforts by the California Public Utilities Commission (CPUC) and California Energy Commission (CEC). In December 2022, CAISO, the CEC, and the CPUC signed a memorandum of understanding to improve energy transmission and generation planning in California by increasing the level of coordination among the three agencies. By tightening the linkage between transmission planning, generation planning, resource procurement, and the processes used to connect new resources to the grid, the agencies hope to accelerate what has been an extremely slow and often contradictory planning and approval process.

CAISO predicts doubling of transmission capacity and dramatic increase in renewable generation over next decades

In its 20-Year Transmission Outlook, CAISO determined that California will need over 53 GW of utility-scale solar generation, over 24 GW of wind generation, 37 GW of battery energy storage, 4 GW of long-duration storage, and over 2 GW of geothermal generation. The following graphic illustrates the integration of these expanded renewable energy resources into the California grid over the next two decades.

CAISO 20-Year Transmission Outlook[3]

Source: CAISO

To achieve this unprecedent target, the Draft Transmission Plan projects that California must create more than 4 GW of new generating capacity each year for the next 10 years, equaling at least 40 GW over the next decade.[4] However, while the draft plan anticipates the addition of 4 GW each year, CAISO has acknowledged the accelerating electrification of many industries — in particular, the transportation sector — and thus anticipates that its 2023-2024 plan will increase those numbers to 7 GW per year, for a total of 70 GW by 2033.[5] As of 2018, California had just over 80 GW of total electric generating capacity;[6] CAISO’s planning sets the stage to almost double that total capacity in the next decade.

A trend has emerged in the CAISO planning process of dramatic year-over-year increases to projections:

CAISO Transmission Plan Projected GW Added to CAISO Grid Annually
2020-2021 (final) Approx. 1 GW[7]
2021-2022 (final) 2.7 GW[8]
2022-2023 (draft) 4 GW[9]

Planned renewable energy dominates the new sources. By 2033, CAISO plans for over 17 GW of solar generation, over 3.5 GW of in-state wind generation, and over 1 GW of geothermal development. In addition, the Draft Transmission Plan highlights the long-term need to develop 3-5 GW of offshore wind power generation[10] and over 4 GW of long duration battery storage,[11] both of which involve new and rapidly developing technologies gaining speed in California.

To bring these renewable resources to market, the Draft Transmission Plan calls for 46 transmission projects with a total anticipated cost of over $9 billion over the next decade.[12] This projection represents a sharp increase in transmission projects. In comparison, last year’s Transmission Plan identified half this number — 23 projects with a total anticipated cost of $2.9 billion[13] — while the 2020-2021 Transmission Plan only called for three transmission projects.[14] The increasing demand for clean energy, continued electrification of transportation and other industries, and requirements of SB 100, which mandates that 100% of electric retail sales to end-use customers come from renewable energy and zero-carbon resources by 2045, spurred the massive jump in transmission capacity demand, reflecting the rapidly evolving nature of the state’s planning process. The planned transmission projects are located across the state, linking existing and anticipated renewable sources with demand centers.[15]

California must streamline and incentivize infrastructure buildout

Both the new renewable energy sources and the transmission buildout identified in the Draft Transmission Plan are critical to achieving California’s goal of becoming carbon neutral by 2045. However, this scale of development will require substantial time, investment, and political will. If California is to achieve this level of infrastructure buildout over the next decade, it must make a sustained effort in terms of both financing these projects and legislative support for streamlining the regulatory approval process for transmission lines.

Transmission lines and utility-scale renewable projects often take years to permit and construct. Both the US Department of Energy (DOE) and the CEC have recently identified challenges with new transmission line development as a critical bottleneck to achieving federal and state clean energy goals.[16] Transmission lines are especially challenging infrastructure projects due to their linear nature, which results in impacts across a range of resource categories and jurisdiction areas. In addition, the CPUC’s approval process for transmission lines has been laborious and often lasts for multiple years, even before considering litigation or appeals.

Recent legislative efforts may offer some help for projects, but a much broader suite of financial incentives and regulatory streamlining will likely be necessary. For example, AB 205, which was signed into law last year, significantly expanded the jurisdiction of the CEC and encourages the development of new clean energy projects.[17] AB 205 expanded the CEC’s jurisdiction to cover certain priority transmission lines, which might help facilitate the approval process for qualifying transmission projects. However, to date, AB 205 has not been applied by any new projects, leaving an open question of whether it will materially accelerate new covered projects.

On the federal level, the Infrastructure Investment and Jobs Act (Act), signed into law in 2021, aims to help states and local governments update aging infrastructure. Using funds from the Act, the DOE has developed a $2.5 billion Transmission Facilitation Program (TFP) to accelerate the buildout of long-distance, high-capacity transmission lines across the country.[18] In addition, the Inflation Reduction Act, signed into law in 2022, includes provisions to spur transmission line development, such as the appropriation of $2 billion for the DOE to make direct loans to non-federal entities to construct or modify electric transmission facilities that have been designated “necessary in the national interest.”[19]

Next steps

Approving and building transmission lines is a complex, often contentious process. The state will need to make a sustained effort in terms of both financing and legislative support to achieve the level of infrastructure buildout envisioned in the Draft Transmission Plan. The unprecedented scale of the buildout will be an ambitious — but necessary — undertaking, requiring significant investment, strong legislative support, and close coordination among numerous agencies.

CAISO is currently inviting stakeholder input on the Draft Transmission Plan before the final plan is presented for approval to the CAISO Board of Governors in May 2023. Comments are due by end of day April 25, 2023, and can be submitted via the CAISO website here.

Latham & Watkins will monitor CAISO transmission planning, among other decarbonization efforts in California, and provide updates regarding further developments.


[1] AB 32, passed in 2006, originally set a target of reducing emissions to 1990 levels by 2020. SB 32 strengthened the state’s GHG reduction target to at least 40% below 1990 levels by 2030. California committed to even bolder targets with adoption of AB 1279 last year, which directs the state to become carbon neutral no later than 2045.

[2] California Energy Commission, “2018 Total System Electric Generation,”

[3] CAISO 20-Year Transmission Outlook, 2. Available at: See also, CAISO 2022-2023 Transmission Plan Stakeholder Presentation (April 11, 2023), 8. Available at:

[4] CAISO 2022-2023 Draft Transmission Plan, 12. Available at:

[5] Id.

[6] California Energy Commission, “2018 Total System Electric Generation,”

[7] CAISO 2021-2022 Transmission Plan, 1. Available at:

[8] Id.

[9] CAISO Draft 2022-2023 Transmission Plan, 12.

[10] In December 2022, the Bureau of Ocean Energy Management held an offshore wind (OSW) energy lease sale for the Morro Bay Wind Energy Area (WEA) and the Humboldt WEA.[10] For more on the OSW lease sale, see this Latham blog post.

[11] CAISO 20-Year Transmission Outlook, 2.

[12] For end users, the total cost of these projects translates to approximately $0.50 per kilowatt-hour (kWh).

[13] CAISO 2021-2022 Transmission Plan, 11.

[14] CAISO 2020-2021 Transmission Plan, 3. Available at

[15] For a detailed map of the locations of the planned transmission projects, see CAISO 2022-2023 Draft Transmission Plan, 4.

[16] US Department of Energy, Office of Policy, “Queued Up But in Need of Transmission: Unleashing the Benefits of Clean Power with Grid Infrastructure” (Apr. 2022), 1-3. Available at: California Energy Commission, Report to the Governor on Priority SB 100 Actions to Accelerate the Transition to Carbon-Free Energy (Sept. 2021), 12-13. Available at:

[17] For more on AB 205, see this Latham blog post.

[18] US Department of Energy, Transmission Facilitation Program. Available at

[19] For more on the IRA, see this Latham Client Alert.