Berkeley, California is home to the Department of Energy’s Lawrence Berkeley National Laboratory, but for more than two years, the entire city of about 124,000 has served as a sort of giant energy lab.

Berkeley was the first community in the country to enact a ban on new natural gas infrastructure, a prohibition that took effect in January 2020.

The ordinance includes all new construction, except for building additions and remodeling projects. Developers, builders, and owners of new structures must find alternatives to natural gas for heating spaces, drying clothes, cooking, and heating water.

So far, with one exception, the ordinance has sparked no major pushback, and states and communities around the country are adopting similar policies, even as some states have moved to preemptively prohibit local communities from adopting natural gas bans. A developer can seek an exemption to the Berkeley ban if city officials are convinced that no good alternatives exist, but, so far, only one exemption has been officially applied for — and none granted.

“Overall this has gone well for us, this transition,” said Sarah Moore, sustainability program manager in the city’s Office of Energy and Sustainable Development (OESD). “It has been a big learning process for all of us, and so we have tried to work with our residents as well as our developers.”

Berkeley’s natural gas ban is aimed at promoting electrification and avoiding the carbon emissions that come from burning natural gas. The city argues the ban also improves IAQ, avoids potential natural gas explosions, and can make housing more affordable.

Berkeley has since 2017 offered outreach and workshops on the benefits of all-electric construction, and helps link developers to electrification resources and experts, said Billi Romain, Berkeley’s OESD manager.

“Local building professionals, including developers, architects, engineers, contractors, and tradespeople, along with property owners, have been generally supportive and interested in learning about all-electric buildings with an appreciation of the positive health, safety, and climate impacts associated with all-electric construction,” Romain said.

“It is a different way of building, so a lot of our work has included education and helping people understand the technologies and the availability of them,” Moore said.

Berkeley is an established, built-out city where most new construction is infill development, so the effects of the natural gas prohibition, in force for less than three years, haven’t yet been dramatic.

Moore said that the structure category of detached “accessory dwelling units” (ADUs) — also called mother-in-law suites — has seen the most projects affected by the ban, with about detached 50 ADUs permitted in 2020 and 2021. It’s fair to assume, Moore said, that the majority of those new structures would include gas infrastructure absent the ban. (ADUs built within an existing structure are considered additions and not subject to the ban.)

Only a handful of commercial projects have been subject to the ban, including recently approved plans for a three-story, 159,143-square-foot building intended for research and design and light manufacturing use, and the Berkeley Commons, an under-construction life sciences campus with two main buildings totaling nearly 539,000 square feet. The Berkeley Commons developers were planning a more sustainable complex, without natural gas infrastructure, even before the ban.

Romain said the city has not yet tried to estimate the quantity of carbon emissions that have been avoided because of the prohibition.

The city has only encountered one serious obstacle to the gas infrastructure prohibition, a lawsuit by the California Restaurant Association (CRA), which contends that federal law preempts the city’s ordinance.

The city prevailed in the U.S. District Court for the Northern District of California last year, but the case is still pending in the Court of Appeals for the Ninth Circuit. Oral arguments were heard in May, and a decision is expected later this year.

“The loss of flame cooking in restaurant settings would dramatically impact restaurant kitchens, where chefs rely on gas stoves to grill vegetables, sear meats and create meals of all kinds inspired by cuisines from all over the world,” said Jot Condie, the CRA president and CEO, in a written statement. “Any law mandating the use of electric rather than gas stoves reduces those choices, and is also likely to impact what restaurants pay for energy in the future.”

The natural gas infrastructure ban steers builders toward electrification for heating spaces, heating water, drying clothes, and cooking, and when fossil fuels like coal and natural gas are burned to generate electricity, that means carbon output.

But California is increasingly moving toward non-fossil fuel sources of power, such as wind and solar, and plans to have all of its electricity generated by clean sources by 2045.

Berkeley is on a much faster track. The vast majority of electric customers in the city, both residential and non-residential, get power through East Bay Community Energy (EBCE), a not-for-profit public agency in Alameda County that works to buy power for member communities from clean sources, officials said. The Berkeley City Council voted last year to transition all of the city’s EBCE customers to the agency’s 100% renewables-generated service. Residential customers made the switch in March, and non-residential customers are set to transition this fall, said Moore.