From Vienna’s bold geothermal “moonshot” to a surging heat pump boom in the United States, cities are ditching gas for cleaner, smarter ways to stay warm—driven by climate urgency, political shifts, and technological leaps.
Five months after vowing to cut ties with Russian gas, Vienna is doubling down on alternatives with a bold effort to harvest heat from an underground water reservoir and feed it into its vast 1,300-kilometre district heating system.
This isn’t the first time Vienna is finding ingenious ways to keep its citizens warm through cold Austrian winters, reports Bloomberg. A decade ago, the city partnered with a local cookie factory to use waste heat for nearby apartments.
Now, with ethical and economic imperatives driving Vienna’s rupture with Russian gas, such ingenuity is coming to the fore again, as the city invests US$21 billion to expand its district heating system and develop source new forms of energy to feed it.
Most “audaciously,” writes Bloomberg, city engineers are using fracking technology to bore down into the Earth, hoping to tap the giant Aderklaaer Konglomerate, a hot water reservoir located some three kilometres below Vienna’s streets.
“It’s a moonshot,” Jürgen Czernohorszky, climate city councillor for Vienna’s ruling Social Democrats, told Bloomberg. “But our job is to come up with bold missions to transform the city for the century ahead.”
Vienna’s district heating network supplies heat and water to more than 200,000 homes, with the largest heat source being the Spittelau waste incinerator. Hopes are that heat from the Aderklaaer, fed into the network via massive heat pumps, will soon keep another 20,000 Viennese households warm. Wien Energie, the city-owned utility, is aiming to double the number of homes it reaches, to about two-thirds of Vienna’s housing stock.
Aiding this effort is heat from the data centres that are popping up around the Austrian capital. Server farms at both the International Atomic Energy Agency and the University of Vienna now feed waste heat into the network.
Austria is governed by the Russia-friendly, climate-skeptic Freedom Party, which may slow Vienna’s quest for energy independence, but Bloomberg writes that it will not be derailed. “Resources have already been budgeted and the nationalist-conservative bloc remains well short of the kind of parliamentary majority it would need to overrule municipal policy.”
In the United States, meanwhile, gas for home heating is getting something of the cold shoulder, as “heat pumps just keep getting hotter,” reports Canary Media, citing 2024 data from the Air Conditioning, Heating, and Refrigeration Institute.
Americans bought 37% more air-source heat pumps than gas furnaces during the first eleven months of 2024, an increase of 16% over 2023.
One reason for their growing popularity is that heat pumps can be as much as four times as efficient as fossil-fuel systems. And as both consumers and contractors grow more familiar with the technology, many states are encouraging wider heat pump adoption.
California, Colorado, Maine, Maryland, Massachusetts, New Jersey, New York, Oregon, and Rhode Island are leaders, pledging last year to boost heat pumps to at least 65% of residential heating and cooling equipment sales by 2030.
However, California’s efforts may take a hit this year, as Los Angeles waives its all-electric requirement on new builds to expedite rebuilding in wake of the city’s devastating wildfires.
Another potential impediment is the new U.S. government. Federal and local incentives have been working to make buying and installing heat pumps more affordable, with federal rebates and credits under the Inflation Reduction Act offsetting one-third to half of the cost. But “how long these incentives might last under Trump is an open question,” writes Canary Media.
