The California Energy Commission (CEC) voted to adopt the policy today as part of the state's Building Energy Efficiency Standards, following more than two years of work with a wide range of stakeholders to develop the technical requirements.
It would be the first such mandate nationwide and California's latest step to aggressively curb greenhouse gas emissions. About 20 percent of California's new homes are built with solar arrays and the state has held about a third of the nation's total jobs in solar since 2013, according to the San Francisco Chronicle.
The Golden State is one step closer to becoming The Solar State.
"Under these new standards, buildings will perform better than ever, at the same time they contribute to a reliable grid", said Commissioner Andrew McAllister, the Energy Commission's lead on energy efficiency.
The commission projects that more than 100,000 single-family homes and nearly 50,000 multi-family buildings will be built across the state in 2020.
But Republican legislative leaders argue Californians can not afford to pay any more for housing in what is already an extremely expensive market.
California, which is routinely a leader in environmental regulatory efforts, would be the first state in the country with such a requirement.
It's possible that with the new rule in place, the costs of solar could go down, and both panels and installations could get a lot cheaper.
California law requires that any new building standards must be cost-effective to consumers - meaning that their energy bill savings over the life of the building is greater than any increased construction costs due to the mandate. The commission's analysis says the solar panel mandate will have "notably less impact on the housing market than 4-6 months of normal median family home price inflation". Sunrun, however, focuses on installing solar power systems on existing homes, not new ones, according to Bloomberg. Exceptions are made for homes with roofs that would receive excessive shade during the daytime or homes with roofs too small to benefit from a few solar panels.
A study by online real estate platform Zillow found starter homes advertising a solar energy system sold for 40 percent more than comparable homes without sun power. "I think we'll see more solar projects coming up in the near future".
The state's building sector is the second-largest source of greenhouse gas emissions when fossil fuels power plants are factored in. "[In] California, we do believe in climate change, we do believe in facts ..."
"I like solar. I just don't like the state mandating it", said Joe Durocher.