Peaker Plants Needed to Integrate 33% Renewables? Not Likely

For more than a year, the California Independent System Operator (CAISO) has been engaged in a cutting-edge modeling effort simulating how a 33% renewable future might affect the state’s grid reliability.

This ‘renewable integration’ modeling ought to predict whether flexible resources (be they demand response, energy storage or gas-fired peaker plants) will be needed in 2020 to make up for unpredicted variability in wind and solar generation, under various 33% renewable energy mixes.

Throughout the stakeholder process, Vote Solar has been working hard to demonstrate that solar variability is not as problematic as some have feared. In fact, it is addressable through state of the art forecasting, improved grid protocols, and application of a concept known as geographic diversity (see a recent paper from Lawrence Berkeley Labs and a Vote Solar white paper on the topic.)

After much educating, testifying and nail-biting on Vote Solar’s end, CAISO presented its most recent modeling results at a meeting in Sacramento on Tuesday, May 10. We are delighted to report that the latest CAISO modeling, taking into account the gas-fired power plants already built or approved to be built by 2020, suggests that no additional resources will be needed to integrate 33% renewables by 2020 — great news for clean air and for ratepayers’ pocketbooks! If California can integrate fully 33% renewables without additional peaker plants, other states should follow suit.

Next, the California Public Utilities Commission may hold hearings on the CAISO model results, before deciding later this year whether to order California utilities to buy resources for renewables integration. Stay tuned…

Vote Solar is a non-profit grassroots organization working to fight climate change and foster economic opportunity by bringing solar energy into the mainstream.