How Not to Waste Clean Energy: New Support for CA’s AB 813

Important new evidence just surfaced about a growing problem that burdens California’s clean energy transition: we are quite literally throwing away increasing amounts of clean energy, enough during some months to power more than 100,000 households with pollution-free electricity.  Fortunately, a solution is already at hand.

With the California legislative session in its final month, a crucial unfinished task is removing barriers to full integration of the western power grid, which would find users for that wasted clean energy while reducing our utility bills, improving reliability and cutting pollution to the benefit of all Californians. Broad support has emerged for AB 813 (Chris Holden, D-Pasadena), which authorizes the California Independent System Operator (CAISO), in partnership with others across the West, to become a full-fledged regional transmission operator (there are six others already in operation elsewhere in the United States).

Lack of timely access to out-of-state electricity markets is forcing California to waste growing amounts of wind- and solar-generated electricity by switching off the generators, which is called “curtailment.”

Here are the key findings of a new report by Secure California’s Energy Future:

New data from the California Independent System Operator (CAISO) show that renewable energy curtailment in California has risen significantly over the past four years, resulting in major losses of opportunity to use and generate inexpensive clean energy .

  • Curtailment during the month of May surged from 10,000 megawatt-hours (MWh) in 2014 to over 70,000 MWh in 2018. This is enough clean energy to power more than 130,000 homes in California for a month. This year also saw a new peak of over 94,000 MWh curtailed in March 2018. That equates to 170,000 households that could have been served by renewable energy for that month.
  • In the first seven months of 2018 alone, California curtailed over 315,000 MWh of renewable generation: enough clean energy to power San Francisco for 20 days.
  • Unless something changes, if California meets its target of generating 50 percent of electricity from renewable resources in 2030, the Union of Concerned Scientists estimates that 5 percent of available renewable generation would be curtailed – the equivalent of losing almost 5 million MWh per year (which could serve more than 750,000 average households). This represents 2.14 million metric tons of carbon dioxide (CO2) pollution that could be avoided annually if that energy is instead used to replace a fossil fuel-emitting resource. That’s equal to two-thirds of the annual emissions from a giant coal-fired power plant (500 MW).

Here is the CAISO’s graph of monthly curtailment for the past three years: 

(Source: California Independent System Operator)

Wasting growing amounts of our state’s clean energy is no way to advance California’s ambitious energy and climate goals. We need full western grid integration, and AB 813 is the essential next step.

About the Authors

Ralph Cavanagh

Energy Co-Director, Climate & Clean Energy Program

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