Juneau company plans to bring seawater-based heating to downtown

Renewable energy company Juneau District Heating on Tuesday announced its plans to build a heat pump system that can provide heat to downtown Juneau using technology that pulls energy from seawater in Gastineau Channel.

The process, a sort of reverse refrigeration, takes a small amount of heat extracted from the water and compresses it with a small amount of electricity to create enough heat to warm buildings. Duff Mitchell, managing director of parent company Juneau Hydropower Inc., said the system would use energy from the proposed Sweetheart Lake hydropower project to power the heat pumps.

The renewable energy technology isn't new to Alaska. The Alaska SeaLife Center in Seward and the NOAA Ted Stevens Marine Research Facility in Juneau use similar systems to heat their buildings.

But, Mitchell said, the larger scale of this project would make it the first of its kind in North America. The plan is to heat a series of buildings, not just one at a time.

"This is an Alaska-based tech that other places in America can look at it," Mitchell said.

Mitchell said the company meets qualifications for a $175 million loan from the Department of Energy to pay for the Sweetheart Lake hydroelectric facility and the heating system. The company should secure its Federal Energy Regulatory Commission license in July, with plans to begin construction shortly after. Mitchell said the company hopes to have hydropower and district heat available for sale in 2018.

Mitchell said most business and homeowners in Juneau use a mix of heating oil, propane and electricity. The heating district's costs will be competitive with the cost of buying fossil fuel heat, he said, and will be even more stable when oil prices are high.


The Juneau district isn't the first heating district to be considered in Alaska. Andy Baker, an Anchorage-based renewable energy consultant with his own company, YourCleanEnergy, is working with the city of Seward to create its own small heating district. In an interview Tuesday, Baker, a consultant on the Juneau project, said Seward submitted its grant application to the Alaska Energy Authority's renewable energy fund and scored well. The city is now waiting to see if the Legislature approves funding for the project.

Jill Ramiel, owner of the Silverbow Inn, attended the announcement in Juneau. She said she's very interested in the project, especially if it can lower heating bills for her downtown Juneau business. Heating costs are her highest bill and she welcomed any idea that could lower them.

"I didn't hear anybody think it was a bad idea," she said in a phone interview Wednesday. "Everyone thought it seemed incredibly exciting."

Suzanna Caldwell

Suzanna Caldwell is a former reporter for Alaska Dispatch News and Alaska Dispatch. She left the ADN in 2017.