Sarah Hancock

In 2018, the California Building Standards Commission approved a mandate requiring all new homes under three stories in the state of California to install solar panels. This solar roof mandate, which is the first of its kind in the United States, will go into effect on January 1, 2020 . While this new mandate enables groundbreaking advancement of clean energy, incentivizes energy storage, and promotes a variety of home energy efficiency upgrades that will collectively reduce energy use in new homes by more than 50 percent, there are various solar system requirements, flexibility measures, deployment and financing options, costs, building process provisions, maintenance responsibilities, and energy savings estimates within the updated building code that California homeowners should be aware of and understand.

System requirements

California’s solar roof mandate is applicable to new residential buildings three stories tall and under and states that the solar PV system must be large enough to net out the annual energy usage of the home in kilowatt-hours. This means that, depending on their location within the state and their house’s energy efficiency, the average California homeowner should expect their solar energy system to be sized between approximately 2.7 and 5.7 kilowatts. In addition to solar, the mandate encourages but does not currently require the deployment of technologies such as battery storage and heat pump water heaters in newly built homes.

Flexibility measures

A number of flexibility measures are included in California’s solar roof mandate, including the option for builders to deploy community solar rather than rooftop solar for new homes so long as they receive approval from the California Energy Commission and coordinate with the local utility. Although pursuing community solar for large-scale projects reduces labor costs for builders, it may not be the most beneficial option for homeowners from a cost perspective; currently, California’s regulations prevent homeowners from taking advantage of net metering while in a community solar arrangement. Another flexibility measure built into the code allows potential exemptions from the mandate for homes where electricity rates are lower than the cost of solar power or where the roof cannot sustain solar panels due to shading or other reasons.

Solar deployment and financing

Under the mandate, home builders have options in terms of how they go about outfitting each new house with solar. As mentioned above, builders do have the ability to pursue community solar rather than rooftop solar for residential buildings. However, builders who choose to go the rooftop route have multiple courses of action that they may take within that sector as well. One option is for builders to request bids from and outsource projects to general contractors and solar companies such as SunPower. Under this scenario, the builder could either allow the project to be rolled into the overall price of the home and paid for through the mortgage or permit homeowners to pay for the system upfront in cash, obtain a loan to pay for the system, or sign into a lease. Another option is for builders to bring the solar process in-house and create their own solar division within the company. Financing options for homeowners would likely be similar to those available for outsourced projects.