In a historic move, California became the first state in the U.S. requiring solar power to be installed on all new homes and residential buildings built in 2020 and beyond. This so-called solar mandate, passed in early December, applies to buildings that are at least three stories high, including apartment buildings.
Homes built according to the solar mandate will use an estimated 53 percent less energy than homes built according to 2016 standards, according to an article in Scientific American. This may slash California’s greenhouse gas emissions by about 700,000 metric tons over three years, according to estimates from the California Energy Commission (CEC).
The solar mandate aligns with the state’s clean energy commitments to shift energy usage to 100 percent zero-carbon by 2045. Previously, California adopted solar rebate, net metering and has routinely updated its energy efficiency standards. Earlier this year, on May 9, the CEC voted to require all new homes built in the state to have rooftop solar power. This month, that requirement was approved unanimously by the California Building Standards Commission.
The revised building code will take effect in January 2020 and require “green” building standards, including provisions on thicker attic and wall insulation, more energy-efficient windows and doors and better ventilation systems. It also includes, but doesn’t require, battery storage and heat-pump water heater options. The mandate offers exceptions for structures in the shade or areas where electricity rates are already lower than the cost of generating solar power.
The solar mandate is expected to greatly increase the number of homes in the state with rooftop solar panels. In 2017 alone, builders took out permits for rooftop solar panels for over 115,000 new homes in California, according to an article in The Orange County Register.
There are many ways homes might meet the solar mandate requirements. New homes built in 2020 and after are required to have rooftop solar panels, access to a community solar project, or complete energy efficient upgrades that compensate in other ways, according to ELECTRICAL CONTRACTOR. The mandate also allows offsite solar production, which means developers can build solar arrays that provide power for multiple homes or contract with utility-owned solar farms.
On average, the 2019 standards may add about $9,500 to the cost of constructing a new home in the state. Estimates include approximately $8,400 for solar panels and $1,500 for other steps to make homes more energy-efficient. Officials believe these added costs will be offset by lower utility bills, citing a potential $19,000 in savings on energy and maintenance costs over a 30-year mortgage. The Energy Commission estimates the mandate may add about $40 per month for the average home, but could save consumers $80 per month on heating, cooling and electricity bills.
The CEC outlined two options homeowners face to avoid the upfront costs of adding solar to their new houses: leasing solar panels or signing a power-purchase agreement, which would pay for the electricity without purchasing the panels. Supporters of the solar mandate maintain homeowners will save enough on their utility bills to balance out the added upfront costs.
Others disagree, arguing that requiring solar panels on new homes is an inefficient response to lowering emissions and only benefits the wealthy. California is already facing a dearth of affordable housing options. One alternative to requiring rooftop solar is building additional solar and wind farms to provide grid-scale renewable energy. Opponents cite figures that show emissions from transportation in the state far outweigh home emissions, 41 percent to 7 percent of all of California’s 2016 emissions, according to the California Air Resources Board.
Still, supporters are unwavering, suggesting that rooftop solar power might help build the grid’s resilience to power failures, natural disasters and wildfires.
Other California policies may be combined with the mandate to help ensure not only wealthy residents of the state participate in this important emissions-reduction program. For example, the state’s cap-and-trade program requires companies to buy emissions permits and mandates them to spend revenue on socially and environmentally disadvantaged areas. This could be one way to make sure more of the state, including low-income families, participates in the solar mandate and is able to buy solar-powered homes in the future.