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    Smoke from California wildfires decreases solar generation in CAISO

    daily CAISO solar generation and California peak air particulate matter level
    Source: U.S. Energy Information Administration, Hourly Electric Grid Monitor; California Air Resources Board, Air Quality and Meteorology System
    Note: CAISO=California Independent System Operator.

    In the first two weeks of September 2020, average solar-powered electricity generation in the California Independent System Operator (CAISO), which covers 90% of utility-scale solar capacity in California, declined nearly 30% from the July 2020 average as wildfires burned across the state. Wildfire smoke contains small, airborne particulate matter particles that are generally 2.5 micrometers or smaller (referred to as PM2.5). This matter reduces the amount of sunlight that reaches solar panels, decreasing solar-powered electricity generation. As of September 28, California wildfires have burned an estimated 3.6 million acres in 2020, an area about the size of Connecticut.

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    Energy Explained -- U.S. Energy Facts