Ameresco, Inc. Announces Partnership with Juneau Hydropower, Inc. to Develop, Construct and Operate 19.8 Megawatt Hydroelectric Facility

Published: 2025-07-08 11:37:42 ET AMRC

Published on 07/08/2025 at 11:37

Ameresco, Inc. announced its partnership with Juneau Hydropower, Inc. to develop, construct and operate a 19.8 megawatt (MW) hydroelectric facility at Sweetheart Lake, 33 miles south of downtown Juneau and its transmission and distribution assets. The Sweetheart Lake Hydroelectric Facility is designed to generate an average of 116,000 megawatt-hours (MWh) annually, providing a 20% increase in baseload clean hydropower over Juneau's current electrical generation. The project scope also covers the installation of a battery energy storage system (BESS), over 40 miles of high-voltage transmission infrastructure, including eight miles of undersea cable that will cross Gilbert Bay, and an interconnection substation with the existing Snettisham Transmission line adding energy security to Alaska's capital city.

This utility will connect underserved, remote areas that have previously relied solely on diesel generation to a reliable, renewable energy source. These components will also enhance local grid reliability and resilience in an area with a history of extreme weather events, including a 2008 avalanche that resulted in power outages that lasted as long as two months. The project is anticipated to increase overall energy transmission in the state by 3%.

Sweetheart Lake is located within the territorial limits of the City and Borough of Juneau, Alaska on the eastshore of Gilbert Bay. Sweetheart Lake drains into Gilbert Bay (an arm of Port Snettisham) via Sweetheart Creek. The hydroelectric dam is expected to offset 82,012 metric tons of CO2 emissions annually.

It will deliver reliable, renewable baseload electricity through a process that does not burn fossil fuels, create pollution, or harm wildlife; and enhances local ecology by utilizing the Sweetheart Lake habitat as a fishery. A true economic and environmental win for Juneau, Alaska, and Nation. One of the planned customers is Coeur Alaska Inc.'s Kensington Mine, located 45 miles north-northwest of Juneau in the Tongass National Forest.

The mine is currently powered by onsite diesel generators but is expected to transition to primarily renewable base-load energy to power operations once the Sweetheart Lake Hydroelectric Facility are operational. In addition to development and construction, the project includes a long-term Operations and Maintenance (O&M) contract, ensuring sustained performance.