Denver eyes turning off natural gas, requiring all-electric new buildings in climate push
Denver wants new construction in a few years to be “net-zero energy” buildings that use only electricity from renewable sources, slashing city greenhouse gas emissions.
The plan, and the building code changes it calls to have phased in starting in 2024, doesn’t explicitly ban future construction from hooking up to natural gas, the fuel used to heat the space and water in nearly all Denver buildings.
But it does call for requiring new construction to use all-electric heat and water heating, first in homes and then offices and large multifamily buildings, and then require enough new solar power with development projects so that new buildings in Denver after 2030 won’t use any energy from fossil fuels.
Denver’s Net-Zero Energy New Buildings & Homes Implementation Plan, produced by the city’s Climate Action, Resiliency & Sustainability office, will be the subject of hearings before a city building code task force this summer and then City Council hearings later this year.
The plan phases in requirements for all-electric systems in new construction, described in one goal as having new buildings and homes be “free from natural gas” by 2030.
City climate officials, when asked, didn’t identify any role natural gas could have in future new buildings.
“This is how we achieve net-zero energy in new construction,” said Elizabeth Babcock, the Denver climate team manager, noting that the city has established greenhouse gas reduction goals. “We know we need to cut emissions in half by 2030.”
There is considerable unease about the plan in Denver’s oil and gas industry, which employs thousands in the city and has helped keep electrical power cheap by producing a bounty of natural gas for utilities to burn.
They argue natural gas is the cleanest-burning fossil fuel and has allowed utilities, like Xcel Energy’s Cherokee power plant north of downtown, to stop burning coal and make major cuts to greenhouse gas emissions.
But that shift by utilities isn’t enough to meet the emissions reduction targets climate advocates and a city task force has said is necessary to have Denver help ward off the worst effects of climate change.
Denver produces 9 million metric tons of greenhouse gases annually, according to a 2019 climate change task force. About 55% of that comes from residential and commercial buildings, Denver’s climate office estimates.
New construction will add 40% of the building stock within city limits by 2050, Denver’s plan says, and making that construction net-zero energy is key to reducing future emissions.
If the climate plan is adopted, building codes would require newly built homes in Denver to have electric heaters and water heating starting in 2024, as would multifamily buildings of seven stories or fewer.
New commercial buildings would have to have electric heating starting in 2024. All-electric commercial buildings — meaning no gas-powered water heating — would start with construction in 2027. Tall multifamily buildings of at least eight stories would be on the same timeline as commercial buildings, the plan says.
And, recognizing that Xcel Energy, the power utility in Denver, doesn’t plan 100% renewable energy by 2030, the city plan calls for new development to include solar power to make the buildings “net-zero.”
The plan envisions building codes that require a growing amount of rooftop space for solar panels or, where that isn’t possible, have developers contribute to a fund that would ensure the addition of off-site solar projects providing enough energy to the grid to power the buildings
By 2030, the city code inspections would aim to ensure new buildings’ energy efficiency performance matched the net-zero energy requirements.
The plan raises the option, during the code transition years, of requiring new buildings that use some natural gas to meet higher energy-efficiency standards, creating an economic incentive to be all-electric. It’s a strategy similar to what’s been adopted by some cities in California.
Asked whether the plan avoids calling for a prohibition on new natural gas hookups to avoid the controversy of it being labeled a natural gas ban, Babcock said: “The objective of the plan was to drive this policy of net-zero energy buildings forward.”
She added the policy would support renewable energy jobs in the city and improve health in addition to helping meet Denver’s climate goals.
Oil and gas industry groups in the city have been seeking clarity from Denver about the plan. They declined to comment for this story.
The Rocky Mountain Institute, a Boulder-based international energy-efficiency policy group, has issued studies finding building electrification in Denver will make new construction cheaper by eliminating needed natural gas infrastructure.
But low-cost natural gas in Colorado makes it possible that some all-electric buildings could cost more to operate than natural gas-using buildings, RMI noted.
“Operating cost creates a significant issue for equity and affordability that will need to be addressed,” the city’s plan concludes.
The city’s report noted electric heating could be more expensive during cold-season peak energy use even though their greater efficiency helps all-electric buildings at other times.
