Dive Brief:

• California's policy to equip new homes with solar panels starting in 2020 passed its final hurdle on Wednesday, following unanimous approval by the state's Building Standards Commission.
• The amendment to the state building code, approved in June by the California Energy Commission (CEC), is meant to save Californians a net $1.7 billion on energy bills, while advancing the state's efforts to build-out renewable energy.
• The historic rooftop solar mandate is already generating out-of-state interest, inspiring proposed legislation by Milwaukee Alderman Tony Zielinski to outfit new residential construction starting in 2019 with solar energy systems. A solar trade group is pleased with California's development, but is waiting to see how it works out before making a big push in other states.

Dive Insight:

The new building energy codes ensure significant investment in residential rooftop solar and energy efficiency as California pursues its goal of getting 100% of its retail electricity sales from carbon-free resources by 2045. Building out rooftop solar deployment would also contribute to the state's renewable portfolio standard, which recent state legislation increased from 50% to 60% by 2030.

The Solar Energy Industries Association (SEIA) spent two years and significant staff time working to ensure the proposal, which also includes advanced energy efficiency measures and incentives for energy storage, would lead to deployment, according to SEIA President and CEO Abigail Hopper.

"Getting California right was incredibly important to us," Hopper told Utility Dive. "I think it will take a little time to prove out, right? So we haven't spent a ton of our resources on shopping the California model to other states."

SEIA continues working to ensure building codes in different states are solar friendly for residential and utility-scale deployment, she said. The solar advocacy group's codes and standards team is also working to educate building planners about the ability to put solar on new homes and bring long term savings to customers, according to Sean Gallagher, SEIA vice president of state affairs.

"What we're focused on more is sort of the national, central codes and standards development," Gallagher told Utility Dive.

The mandate received broad stakeholder support after the initial CEC approval, including support from Southern California Edison and Pacific Gas & Electric. However, the large investor-owned utilities urged caution on the implementation of the order to protect non-solar customers.

Environment America forecast the impacts of equipping all new U.S. homes with solar panels in a report released on Monday. Besides highlighting impacts to reduce carbon emissions and increase solar penetration, the report estimated homeowners could save between $10,000 to $30,000 over a 20-year period with solar-equipped new housing, depending on the extent of a state's pro-solar policies.

More than 60% of voters would support a state mandate for solar panel installation as part of new home construction, according to a July Morning Consult poll. The survey showed a majority of Republican, Democratic and Independent voters all supported a mandate.