FAIRBANKS — The first detailed analysis of ground-source heat pumps in Alaska has determined the technology is a cost-effective heating option in some parts of the state but only marginally advantageous in the Fairbanks area.
Ground-source heat pumps are fairly common in parts of the Lower 48, but they’ve been viewed skeptically as a viable option in the cold soils of Alaska. They use an elaborate system of underground tubing to capture heat from the surrounding soil, which is transferred into a home with an electric pump.
The study, a collaboration between the Cold Climate Housing Research Center and the Alaska Center for Energy and Power, analyzed the performance and economic viability of the systems in Fairbanks, Anchorage, Juneau, Bethel and Seward.
The key to making the heat pumps viable in Alaska is a combination of low electric prices and high costs for traditional heating sources in a region, the study determined.
In areas with cheap electricity and a reliance on expensive fuel oil — such as Juneau and Seward — ground-source heat pumps are a clear winner. Anchorage, whose natural gas supply provides cheap heating and electricity, and Bethel, with pricey electricity, aren’t good candidates for the technology.
Somewhere in the middle is Fairbanks, whose reliance on expensive heating oil is combined with moderate electric rates.
“In Fairbanks it was close,” said ACEP’s Jason Meyer, who led the project. “It’s very competitive.”
The findings are intriguing in a state with limited exposure to the technology. The study estimated only about 50 heat pumps are operating in Alaska, but Meyer said installations have made a small surge in the past three years, a time that coincided with spiking oil prices.
Anecdotal reports indicate the owners of those systems — including about 20 homeowners in the Interior — are pleased with the results.
“Across the board, they were all happy with the performance of their system,” Meyer said. “It was a lot of success and glowing reports.”
The study, which was funded by a $90,000 grant from the Denali Commission, looked specifically at the cost of installing a heat-pump system in a new home, compared to whatever heating system is most common in a particular area. Over the course of 15 years, the study compared the cost of installation, fuel and maintenance for each system.
The up-front costs are considerable for a ground-source heat pump system — $23,000 in Fairbanks, compared to $14,000 for a conventional boiler system — but are slowly offset because no fuel oil is needed to keep the system running.
“There’s no reason, if it’s designed right, why it couldn’t be your whole heating source,” said Colin Craven, head of product testing at CCHRC.
In communities with inexpensive hydro electricity, the pumps have the biggest advantage, since they operate cheaply without emissions. Craven said their environmental benefit is more debatable in the Interior, where electricity plants generally burn coal or diesel fuel for generation.
“I think it’s an open question whether it’s a green technology right now for Fairbanks,” he said.
The study also leaves some key questions unanswered. Meyer said it remains unclear how commercial-scale heat pump operations fare in the analysis, and it’s also unknown whether the systems retain their efficiency over time. Since they draw heat from the ground, there’s been speculation that they may gradually lose performance, he said.
Meyer said some ongoing projects will be monitored to help answer those questions. A ground-source heat pump system was installed at Weller Elementary School a year ago, and CCHRC plans to install a pump next year for continuing research.