For decades, it’s been hard to think of Alaska without thinking of oil. The state has the third highest petroleum consumption, per capita, of any US state. More than three-quarters of people there heat their homes using fossil fuels, according to the International Energy Agency (IEA)—well above the US average. Until recently, Genevieve Gagne-Hawes, a resident of Alaska’s capital, Juneau, was among them. But when she received a bill of almost $900 last March for heating her home during the winter months, she decided to find an alternative.
“I thought it was a joke. I was just gobsmacked,” Gagne-Hawes says.
Oil prices in Juneau hit an average of more than $5 per gallon last winter—25 percent higher than the US national average and nearly five times the current global average, according to one tracker—triggering a rush for heat pumps. Gagne-Hawes decided to install an air source heat pump, which runs on electricity. It has kept her house warm this winter even when the outdoor temperature has dipped below 0 degrees Fahrenheit (–17.7 Celsius).
“I expected it to be fine, but it’s been spectacular,” says Gagne-Hawes. She says the heat pump is saving her roughly $100 a month.
The IEA estimates that switching to heat pumps could reduce global CO2 emissions by 500 million metric tons by 2030. In principle, that means the more people who drop fossil fuel boilers for these devices, the better—in climate terms.
Alaskan oil production has fallen in recent times, and the state is gradually embracing renewables, with 31 percent of its electricity generation coming from renewables, comparable to solar-power-rich Massachusetts. The shift toward cleaner energy is happening on an industrial scale, but also in people’s homes, where heat pumps are beginning to take the place of fossil-fuel-guzzling furnaces. Air source heat pumps use a refrigerant to absorb heat from the outdoor air, which then gets passed on to rooms in a house or a hot water supply.
Some Alaskans are pushing air source heat pumps to their limits, running them even when outdoor temperatures plummet to nearly –30 degrees Fahrenheit (–34.4 Celsius).
Andy Romanoff, the executive director of Juneau-based nonprofit Alaska Heat Smart, estimates that there are about 2,000 heat pumps covering roughly 15 percent of the city, a number that he expects to grow. “We do see a 10 to 15 percent, maybe even 20 percent, increase year-after-year in the number of permits that are being applied for,” he says.
Heat pump installers in Alaska recommended by Heat Smart also say demand for the devices is rising. One installer, Mark Houston, describes a spike in inquiries about heat pumps at the beginning of 2023, more than the number of inquiries he’d received for the whole of 2022. Another, Kris Karsunky, says he installs between 50 and 70 heat pumps a year but fields twice that many requests via phone. Businesses are increasingly adopting the technology, too, he adds.
Juneau gets most of its electricity from lakes that offer a clean hydropower resource. This means that it is particularly ecofriendly to install electrified heating systems in the city.
But, to be fair, Juneau lies at the warmer end of the state and doesn’t tend to experience the same blisteringly cold winter weather that can afflict places farther north like Anchorage or Fairbanks, where using heat pumps could be less cost-effective.
In the village of Eklutna, not far from Anchorage, electrician Derek Lampert has found a heat pump that copes with extreme temperatures. He lives in a house that he built with his father during the pandemic. The walls are 22 inches thick, he boasts. Lampert planned for the house to be as energy efficient as possible, and so he invested in a SANCO2 heat pump, which uses CO2 for a refrigerant. The machine provides space heating and hot water supply.
“We’ve had it as cold as –20 degrees Fahrenheit and it still worked,” says Lampert. “I was getting 135-degree water.”
High efficiency was certainly Lampert’s goal, and overall he’s happy with the results. Financially, at least, the well-insulated house and heat pump setup has proved beneficial. “People in my neighborhood spend more [than my entire electricity bill] on propane and heating oil,” says Lampert.
However, because a heat pump sucks heat indoors from outside, sometimes for long periods, the outer part of the machine can get especially cold and make the device less energy efficient. Heat pumps are generally designed to defrost themselves periodically, but Lampert argues that his model could be better at this. He says he has noticed a fair amount of frosting and ice build-up around the exterior of his heat pump when it’s very cold. “Certainly, the colder it gets, the worse it gets. It just struggles with all the moisture,” he explains.
John Miles, a spokesman for Eco2 Systems, which makes the SANCO2 heat pump, says the current model works down to –26 degrees Fahrenheit (–32 Celsius). He adds that it has various means of checking for frost build-up and that any ice that does form will, eventually, melt away.
Terry Chapin, an ecosystem ecologist and professor emeritus of the University of Alaska, Fairbanks, has a heat pump but notes that his model—designed to work down to –13 degrees Fahrenheit (–25 Celsius)—struggles in the winter months. “It doubled our electricity use when I was using it at very low temperatures,” he says. When the temperature drops below 0 degrees Fahrenheit, he switches back to his oil heating system instead.
Vanessa Stevens, a building science researcher at the National Renewable Energy Laboratory in Fairbanks, says that the latest heat pumps are increasingly cold-hardy.
“We’re actually testing a heat pump in our lab this spring where the cutoff temperature is –31 degrees Fahrenheit,” she says. “That was unheard of 10 years ago.”
Demand in Alaska appears to be rising strongly because heat pumps are becoming more efficient and cost effective, she suggests, adding that there are now companies solely dedicated to heat pump installations—a relatively new development.
Heat pumps have great decarbonization potential, but this depends on context, says Meredith Fowlie, an economist at UC Berkeley. They will be most beneficial as a climate solution when they run on electricity generated predominantly from low-carbon sources—and when manufacturers move away from the least climate-friendly heat pump refrigerants. New homes, or homes requiring a brand-new heating system, should opt for a heat pump as standard now, according to Fowlie. But as heat pumps continue their spread, there must be enough properly trained tradespeople to install them, as well as building codes that promote the use of more efficient systems, says Fowlie.
“There’s a sense of urgency that needs to be balanced against some of the practical, pragmatic challenges that we need to overcome.”
