Overview
Maine is building out renewables in its rural north — where land and wind are plentiful — but faces a transmission bottleneck moving that power south into ISO New England’s load centers. The New England Clean Energy Connect will bring 1,200 MW of Canadian hydroelectricity into the state, and federally backed transmission upgrades in Aroostook County will unlock hundreds of megawatts of planned wind and solar. Maine’s grid also hosts two of the region’s most ambitious battery storage projects, including an 85 MW iron-air system designed to discharge for up to 100 hours.
Generation Projects
Solar
Hersey-area solar proposal in Aroostook County could become a major in-state source of generation if it proceeds. Developers briefed residents on a 5,000-acre solar farm, one of the largest proposed projects in the state.[3]
Wind
King Pine Wind in Aroostook County is a 1,000 MW wind project by Longroad Energy. Maine regulators advanced a transmission plan tied to this project, signaling that the buildout depends on new 345 kV lines to move power south.[4]
Transmission and Grid
New England Clean Energy Connect (NECEC) runs from the Quebec border in Beattie Township to a new converter station in Lewiston, with about 53 miles of newly developed corridor. Massachusetts regulators approved a settlement for NECEC transmission service, designed to deliver 1,200 MW of Canadian hydroelectricity into New England over 20 years.[5][6]
Aroostook Renewable Project received a DOE Transmission Facilitation Program award and includes a new Haynesville substation, a 111-mile 345 kV line to Pittsfield, and a new 38.5-mile 345 kV line to Coopers Mills substation, with 1,200 MW transfer capacity. This is the largest near-term grid expansion in northern Maine.[7] Governor Mills highlighted the $425 million DOE capacity contract for the Aroostook Renewable Project as a priority grid upgrade for northern Maine.[8]
LS Power Grid Maine transmission solution moves forward with a plan to build more than 100 miles of new 345 kV lines and multiple substations to connect Aroostook County renewables to ISO-NE.[4]
Battery Storage
Form Energy long-duration storage in Lincoln Technology Park is an 85 MW iron-air battery designed for up to 100 hours of discharge, backed by a nearly $150 million federal grant. This multi-day duration technology is the first deployment of its kind at utility scale.[9]
Cross Town Energy Storage in Gorham is a 175 MW / 350 MWh battery project by Plus Power, slated to provide grid support beginning in 2025 and described as Maine’s largest battery facility.[10]
Interconnection Queue
ISO-NE maintains a public interconnection request queue covering generation and elective transmission upgrades across New England, including Maine.[12] ISO-NE began its Transitional Cluster Study in October 2025 as part of interconnection reforms, signaling that queue backlogs and study timing remain a near-term bottleneck for new projects.[13]
The DOE-selected Aroostook transmission build and the LS Power 345 kV line plan both target the same constraint: limited ability to move northern Maine wind and solar output into ISO-NE.[4][7]
What to Watch
- NECEC in-service date and initial Canadian hydroelectric delivery volumes into New England.
- Aroostook County transmission construction timeline and impact on King Pine Wind and other Aroostook renewable projects.
- Form Energy long-duration battery commissioning in Lincoln — the first 100-hour iron-air storage system at commercial scale.
Sources
[1] Governor’s Energy Office (Maine), “Draft Maine Energy Plan for Public Comment (Dec 2024),” December 2024, https://www.maine.gov/energy/sites/maine.gov.energy/files/2024-12/Draft%20Maine%20Energy%20Plan%20for%20public%20comment%20Dec%202024.pdf (accessed 2026-01-08).
[2] Maine Yankee, “Decommissioning,” https://maineyankee.com/decommissioning/ (accessed 2026-01-08).
[3] Kathleen Phalen Tomaselli, “Massive solar farm proposal alarms a tiny Aroostook town,” The County, 2025-01-31, https://thecounty.me/2025/01/31/houlton/massive-solar-farm-proposal-alarms-a-tiny-aroostook-town/ (accessed 2026-01-08).
[4] LS Power, “Maine PUC moves forward with LS Power Grid’s Transmission Solution to Deliver Renewable Energy from Northern Maine,” 2023-02-03, https://www.lspower.com/news/maine-puc-moves-forward-with-ls-power-grids-transmission-solution-to-deliver-renewable-energy-from-northern-maine/ (accessed 2026-01-08).
[5] Maine Department of Environmental Protection, “NECEC,” https://www.maine.gov/dep/land/projects/necec/index.html (accessed 2026-01-08).
[6] Massachusetts Department of Public Utilities, “DPU Approves Settlement for New England Clean Energy Connect,” 2025-10-27, https://www.mass.gov/news/dpu-approves-settlement-for-new-england-clean-energy-connect (accessed 2026-01-08).
[7] U.S. Department of Energy, “Transmission Facilitation Program Selections,” 2024-10-03, https://www.energy.gov/gdo/transmission-facilitation-program-selections (accessed 2026-01-08).
[8] Office of Governor Janet T. Mills, “Governor Mills Applauds $425 Million Investment from Biden-Harris Administration to Advance Northern Maine Transmission Line, Strengthen Electric Grid & Embrace Clean, Affordable, Renewable Energy,” 2024-10-03, https://www.maine.gov/governor/mills/news/governor-mills-applauds-425-million-investment-biden-harris-administration-advance-northern (accessed 2026-01-08).
[9] Office of Governor Janet T. Mills, “Governor Mills, Senators Collins & King, and Congresswoman Pingree Announce Nearly $150 Million Federal Grant to Develop World’s Largest Multi-Day Energy Storage Facility in Lincoln, Maine,” 2024-08-06, https://www.maine.gov/governor/mills/news/governor-mills-senators-collins-king-and-congresswoman-pingree-announce-nearly-150-million (accessed 2026-01-08).
[10] Ethan Andrews, “Maine’s first giant battery project set for construction in Gorham,” The Maine Monitor, 2024-01-07, https://themainemonitor.org/giant-battery-project-gorham/ (accessed 2026-01-08).
[11] American Public Power Association, “MMWEC Enters Power Purchase Agreements with Maine Wind Projects,” 2026-01-08, https://www.publicpower.org/periodical/article/mmwec-enters-power-purchase-agreements-with-maine-wind-projects (accessed 2026-01-08).
[12] ISO New England, “Interconnection Request Queue,” https://www.iso-ne.com/system-planning/interconnection-service/interconnection-request-queue/ (accessed 2026-01-08).
[13] ISO New England, “ISO-NE begins interconnection Transitional Cluster Study,” 2025-10-20, https://isonewswire.com/2025/10/20/iso-ne-begins-interconnection-transitional-cluster-study/ (accessed 2026-01-08).