How many hydro power plants are in Maine?

Maine has 51 operating utility-scale hydro power plants with 0.7 GW of capacity, according to the EIA's monthly survey of power plants.

What is the largest hydro power plant in Maine?

Great Lakes Hydro America - ME in Penobscot County, Maine is the largest, at 138 MW. It came online in 1988.

How many hydro power plants were built in Maine in 2025?

0 hydro power plants came online in Maine in 2025, with 0 MW of capacity.

Who is developing hydro power plants in Maine?

Interconnection queues list each project under a project company, not the developer behind it. Cleanview researches the developer of every project and has them on paid plans.

Hydro power plants in Maine

Maine has 51 operating hydro power plants with 0.7 GW of capacity.

Operating51

Updated monthly. Last updated November 2026.

Under 50 MW50–249 MW250 MW and up

Updated monthly. Last updated November 2026.

Maine had 51 hydro power plants online in 2016 and 51 in 2026

2016’162017’172018’182019’192020’202021’212022’222023’232024’242025’252026’26

Hydro power plants online at the end of each year. Source: EIA-860M, compiled by Cleanview.

The 10 largest hydro power plants in Maine

Operating, by capacity

#	Hydro power plant	County	Year online	Capacity
1	Great Lakes Hydro America - ME	Penobscot County	1988	138 MW
2	Harris Hydro	Somerset County	1955	76 MW
3	Wyman Hydro	Somerset County	1940	72 MW
4	Rumford Falls Hydro Facility	Oxford County	1954	45 MW
5	Anson Abenaki Hydros	Somerset County	2008	29 MW
6	Charles E Monty	Androscoggin County	1990	28 MW
7	Brunswick Hydro	Cumberland County	1983	20 MW
8	Worumbo Hydro Station	Androscoggin County	1989	19 MW
9	Gulf Island	Androscoggin County	1926	19 MW
10	Woodland Pulp, LLC	Washington County	1970	19 MW

Hydro power plants that came online most recently in Maine

Newest first

#	Hydro power plant	County	Year online	Capacity
1	Orono B	Penobscot County	2013	4 MW
2	Stillwater B	Penobscot County	2013	2 MW
3	Milford Hydro Station	Penobscot County	2011	8 MW
4	Orono Hydro Station	Penobscot County	2009	3 MW
5	Anson Abenaki Hydros	Somerset County	2008	29 MW
6	International Paper Livermore Hydro	Androscoggin County	2004	9 MW
7	Charles E Monty	Androscoggin County	1990	28 MW
8	Brassua Hydroelectric Project	Somerset County	1989	4 MW
9	Worumbo Hydro Station	Androscoggin County	1989	19 MW
10	Hydro Kennebec Project	Kennebec County	1989	15 MW

The developer behind each project is on paid plans. See plans

How Cleanview tracks hydro power plants

Operating hydro power plants come from the EIA's monthly survey of power plants. Planned projects come from the grid operators' interconnection queues. We research who is developing each one, since a queue lists a project company, not its owner.

Questions about hydro power plants in Maine

How many hydro power plants are in Maine?: Maine has 51 operating utility-scale hydro power plants with 0.7 GW of capacity, according to the EIA's monthly survey of power plants.
What is the largest hydro power plant in Maine?: Great Lakes Hydro America - ME in Penobscot County, Maine is the largest, at 138 MW. It came online in 1988.
How many hydro power plants were built in Maine in 2025?: 0 hydro power plants came online in Maine in 2025, with 0 MW of capacity.
Who is developing hydro power plants in Maine?: Interconnection queues list each project under a project company, not the developer behind it. Cleanview researches the developer of every project and has them on paid plans.