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Renewable Portfolio Standard: Regional Transmission Expansion Assessment

Achieving California's 50% Renewable Portfolio Standard (RPS) will require the integration of more than 21,000 GWh of new renewable generation by 2030. Meeting this objective will require a high penetration of solar photovoltaic and wind capacity, which are intermittent resources that will be accompanied by well-documented integration challenges (see California's "Duck Curve"). 

With California's RPS procurement since 2014 focused almost exclusively on solar PV, issues such as the projected midday over generation and resulting curtailment have already begun to emerge. These challenges will only increase if in-state solar continues to be favored.

There are excellent wind resources available in the West, but none better than those in Southern Wyoming, where projected capacity factors with new turbine technology approach 50%. PA has been retained to:

  1. review the economic case for Wyoming wind, and specifically the extent to which it could reduce California RPS compliance costs; and
  2. to evaluate the range of proposed transmission options available to access it.

Unlocking Regional Market Diversity to Meet Western Energy and Environmental Goals

Download report

Using the California Public Utilities Commission's (CPUC) publicly available RPS Calculator as a basis for levelized cost assumptions, resource curtailment estimates, and renewable energy portfolio scenario analysis, our Regional Transmission Expansion Assessment evaluates the resource diversification potential and cost of Wyoming wind energy versus that of renewable resources already accessible from California.

To facilitate an "apples to apples" comparison between renewable resources, this assessment quantifies the cost of curtailment by resource type as well as the levelized cost of transmission required to gain access to Wyoming wind, thereby arriving at a true levelized cost of electricity (true LCOE) that best represents the cost of a given resource per unit of delivered output.

Key findings of this report include that:

  1. Wyoming wind power represents a cost-competitive addition to California's 2030 RPS compliance generation portfolio;
  2. the proposed TransWest Express HVDC transmission line (TWE Project) is the most viable and cost-effective option for accessing material quantities of Wyoming wind energy from California's load centers; and
  3. the energy cost savings and avoided capacity overbuild costs enabled by the TWE Project and the enhanced resource diversity it facilitates significantly exceed the cost of constructing and operating the line, resulting in $5 billion to $11 billion in net benefits to California ratepayers.

Download our report to learn how you can unlock regional market diversity to meet Western energy and environment goals.

Contact the energy and utilities team


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