California Becomes First State To Mandate Solar on New Homes (bloomberg.com)

California regulators said on Wednesday they have unanimously approved a historic plan that will require most new homes in the state have rooftop solar panels that turn sunlight into electricity starting in 2020. From a report: Most new homes built after Jan. 1, 2020, will be required to include solar systems as part of energy-efficiency standards adopted Wednesday by the California Energy Commission. While that's a boost for the solar industry, critics warned that it will also drive up the cost of buying a house by almost $10,000. The move underscores how rooftop solar, once a luxury reserved for wealthy, green-leaning homeowners, is becoming a mainstream energy source, with California -- the nation's largest solar market -- paving the way.

The Golden State has long been at the vanguard of progressive energy policies, from setting energy-efficiency standards for appliances to instituting an economy-wide program to curb greenhouse gases. The housing mandate is part of Governor Jerry Brown's effort to slash carbon emissions by 40 percent by 2030, and offers up a playbook for other states to follow.