Sacramento, California, USA: California – the world’s fifth largest economy – on Wednesday became the first U.S. state to require all new homes to have solar panels. The rule is part of a plan to cut greenhouse gas emissions by 40% by 2030. The new rule in California would cover all low-rise residential buildings, although houses that are frequently in the shade are exempt. It applies only to new construction.
The mandate approved unanimously Wednesday morning by the California Energy Commission will go into effect on January 1, 2020 for single family or “multi-family” buildings three stories or less. The Building Standards Commission still needs to approve it.
Other, less visible standards were also put in place, like improved window insulation to contain costly, climate-controlled air.
California is already well on its way to meeting aggressive renewable energy goals. State law requires California to generate half its power from renewables like wind and solar by 2030. Utilities say they’ll likely meet this goal 10 years ahead of schedule, in 2020.
Solar panels on new homes can certainly be a boon, powering refrigerators and air conditioning during the day while sending any excess power back into the grid. But they won’t be as significant as other, less flashy mandates.
“They speak to the future,” Michael Picker, president of the California Public Utilities Commission, an agency separate from the state’s energy commission, said in an interview.
“But a much more brilliant solution were energy efficiency standards,” said Picker, referring to the 1970s-era rules mandating that antiquated, power-hungry appliances become far more efficient. While energy demand has doubled across the U.S. since the 1970s, California’s has remained flat, even with its active economy and burgeoning population, said Picker.
“It’s hard for people to love [the 1970s’ mandate], because people don’t see it,” he said. “Solar is not bad, but it’s expensive and it does produce new challenges.”
There are some grievances about added costs from installing solar, which the state estimates could tack on over $10,000 to building a new home. But the energy commission said new homes with solar panels will cut energy use by over half, saving homeowners around $80 a month.
Overall, the price of producing solar energy has dropped significantly, mostly because the price of photovoltaic solar panels — the type mandated on Californian homes — has dropped, the U.S. Department of Energy said last year.
Solar installations can pick up the slack in places that have a lot of power demand, but not enough supply, without emitting heat-trapping greenhouse gases.
During the day, especially at high noon when the sun is directly overhead, the panels will typically produce too much energy.
Solar panels on homes won’t be California’s renewable savior in and of itself, but they will be part of the greater renewable solution. “It’s not any one thing that works,” said Picker, citing that tightly-sealed insulation in homes and efficient appliances continue to contribute to the carbon-mitigation effort.
Even when California homes are powered almost entirely by renewables like solar, they may still need to rely on some natural gas-burning for some time, even if these carbon-emitting plants are only used for around 200 hours a year, said Picker. When the sun starts setting, especially when it’s hot, solar power alone won’t be able to power many homes, requiring energy producing “peekers” to rapidly fire up and meet demand.
“You need something you can spin up real fast,” said Picker. “It’s a counter-effect, and we can deal with it.”
Exactly how much electricity California will produce on new rooftops in the Golden State’s neighborhoods isn’t known. But it relies on one major factor.
“It depends on how much new building construction there is,” said Picker.
California has some of the highest housing costs in the country and has a widespread housing shortage.
Also, because of the way California calculates electric bills, net metering allows consumers with solar panels to get credit for the electricity they produce, lowering their utility bills.
California, which is routinely a leader in environmental regulatory efforts, would be the first state in the country with a state-wide requirement. Several cities, including San Francisco and South Miami, Florida, have residential solar panel requirements.