California's solar panel law goes into effect

In this Oct. 16, 2015 file photo a solar panel is installed on the roof of the Old Governor's Mansion State Historic Park in Sacramento, Calif. After extensive renovations, Gov. Jerry Brown and his wife, Anne Gust Brown moved into the mansion in late 2015, becoming the first chief executive to live in the home since Ronald Reagan in 1967. The California Energy Commission will take up a proposal, Wednesday, May 9, 2018, to require solar panels on new residential homes and low-rise apartment buildings up to three starting in 2020. (AP Photo/Rich Pedroncelli, File)

In California, a new building standard requiring solar panels on all new homes and low-rise apartments takes effect on Jan. 1. The requirement was approved by the California Energy Commission in May of 2018.

The law was noted as being the first such statewide mandate in the United States, as the California attempts to lead the country in curbing greenhouse gas emissions. The requirement was supported by a number of builders, utilities and solar manufacturers in the state.

Homebuilders can either buy rooftop panels or lease them from a solar provider, according to the San Francisco Chronicle.

While the mandate will only apply to newly-constructed homes, many homeowners are choosing to install rooftop panels thanks to a rebate program.

The California Energy Commission estimates that over 30 years, homeowners will save thousands of dollars in energy and maintenance costs.