The California Energy Commission [official website] adopted new standards [text, PDF] Wednesday that will require all newly constructed residential buildings to be built with solar photovoltaic systems installed.

The requirement for the solar photovoltaic systems is estimated to reduce greenhouse gas emissions equivalent to 115,000 fossil fuel cars. The changes would take effect January 1, 2020. In addition to the solar installation, the regulations would also require changes to thermal envelope standards, ventilation requirements, and nonresidential lighting requirements. The standards still need to be approved by the California Building Standards Commission [official website] before they can be enacted.

The costs of the changes are estimated to be $40 per month on a 30-year mortgage for residential homeowners. However, all of the changes are also estimated to result in a savings of $80 per month on heating, cooling and lighting bills, according to a California Energy Commission <a href="statement [press release].

The reduction in greenhouse gas emissions has been a growing concern in the US. President Donald Trump announced [JURIST report] in June 2017 that the US would be withdrawing from the Paris Climate Accord. However, in September 2017, the US Senate Appropriations Committee approved [JURIST report] a $10 million payment to the UN agency that oversees the Paris Climate Accord.