Health, Climate, and Energy Co-Benefits of 2020 Residential Solar Panel Mandate in California

Abstract

Background: Power plants are primary emitters of greenhouse gases and criteria air pollutants, which are associated with harmful health impacts including increased risk of premature mortality. Therefore, the residential solar panel requirement set forth by the California Energy Commission for the 2019 Building Energy Efficiency Standards, Title 24, Part 6, plays an important role in promoting public health. Objective: We used the Co-Benefits of the Built Environment tool to estimate emissions reductions, health, and climate co-benefits resulting from the residential solar panel mandate from 2020 to 2050. Methods: We projected the electricity demand impacts, calculated future local emissions factors to derive the associated emissions reductions, and employed reduced complexity models to estimate human health impacts. Results: In California, we found 32,664 metric tons of cumulative averted criteria air pollutants, in addition to greenhouse gas reductions equivalent to removing 8.67 million gas-fueled cars from the road. By 2050, we conservatively estimate monetary co-benefits over $546.4 million (health) and $2.88 billion (climate). Electric utility cost savings by 2050 exceeded the expected increased upfront cost of purchasing a new home under the mandate by more than twofold. Significance: Co-benefits of building energy efficiency standards can be quantified and used as a strategic tool to optimize human and environmental health.