Maine regulators have approved an 800-megawatt onshore wind farm and a 1.2-gigawatt transmission line that will move that power into Massachusetts, Connecticut, Vermont, and Rhode Island, creating a multi-state cost-sharing mechanism that directly targets the region’s highest-in-the-nation electricity bills and its stubborn winter reliance on oil-fired generation. The two projects, awarded to Clearway Energy Group and Avangrid respectively, are projected to deliver $2.4 billion in economic output and could displace more than 10 percent of the oil burned for power during cold snaps. With offshore wind development stalled by federal permitting headwinds, this onshore corridor represents the most concrete progress in nearly two decades of efforts to unlock Northern Maine’s wind resource for the broader New England grid.
How the Projects Fit Together and Why the Cost-Sharing Model Matters
The Maine Public Utilities Commission’s decision binds two distinct but interdependent assets: King Pine Wind, an 800-MW onshore facility Clearway will build in Aroostook County, and the 1.2-GW King Pine Transmission line Avangrid will construct to connect it to the ISO-New England system at a new substation in Pittsfield, Maine. The transmission line is sized 50 percent larger than the initial wind farm’s output, a deliberate design choice that anticipates additional generation – likely more onshore wind or future solar – connecting to the same corridor without requiring a second major build-out.
Crucially, the PUC structured the procurement so that ratepayers across the four receiving states will share the transmission costs through ISO-NE’s regional tariff, while the wind farm’s output will be sold under long-term contracts to Massachusetts and Connecticut utilities under those states’ clean-energy procurement mandates. That bifurcation – socializing the wires, contracting the energy – mirrors the cost-allocation framework FERC Order 1000 envisioned for multi-state transmission but has rarely achieved at this scale in the Northeast. Maine ratepayers themselves are largely shielded from the transmission tab, a political necessity given the state’s history of rejecting earlier proposals that loaded costs onto local bills.
The $2.4 billion economic-output figure cited by the PUC covers construction spending, operations jobs, and tax revenues over the projects’ lifetimes. For context, that is roughly equivalent to the direct capital cost of a single large offshore wind farm of comparable nameplate capacity, but spread across a supply chain that leans heavily on Maine-based contractors, timber-road logistics, and existing port facilities in Searsport and Eastport rather than specialized European installation vessels. The 10-percent oil-displacement estimate comes from ISO-NE modeling of winter peak days when dual-fuel gas plants switch to distillate; each megawatt-hour of wind injected at that margin avoids the most expensive, highest-emitting marginal unit on the system.
Onshore Wind Gains Strategic Weight as Offshore Faces Federal Friction
That points to a broader recalibration in Northeast decarbonization strategy. Since 2021, the Bureau of Ocean Energy Management has auctioned more than 15 GW of offshore lease area in the Gulf of Maine and Southern New England, yet only Vineyard Wind (800 MW) and South Fork Wind (130 MW) have reached commercial operation. Permitting timelines for subsequent projects – Beacon Wind, Revolution Wind, Empire Wind – have stretched beyond original commercial-operation dates by 12 to 24 months, driven by NEPA review delays, Jones Act vessel constraints, and, most recently, a January 2025 executive order pausing new federal offshore wind approvals pending a “comprehensive review.”
By comparison, King Pine’s onshore permitting path – state-level site certification, Army Corps wetlands review, and ISO-NE interconnection studies – is measured in quarters, not years. Clearway has indicated a target commercial-operation date of late 2028 for the first 400 MW, with full build-out by 2030. That timeline aligns with Massachusetts’ 2030 clean-energy standard (40 percent of load from eligible resources) and Connecticut’s 2030 zero-carbon target, both of which now face a supply gap if offshore projects slip further. If King Pine delivers on schedule, it could supply roughly 2.5 TWh annually – about 3 percent of ISO-NE’s current annual energy demand – at a levelized cost industry sources estimate in the $45-$55/MWh range, well below the $70-$90/MWh strike prices seen in recent offshore solicitations.
The parallel ISO-NE study of a separate Northern Maine transmission upgrade – often referred to as the “Aroostook Reinforcement” – underscores the grid operator’s recognition that one 1.2-GW line will not exhaust the region’s developable onshore resource. ISO-NE’s 2023 interconnection queue shows over 3 GW of active wind and solar requests in Northern Maine alone. If the King Pine line reaches its thermal limit, the next increment of transmission will likely require a new right-of-way or a voltage upgrade to 345 kV, decisions that will hinge on whether state clean-energy procurements continue to favor onshore wind over imported Canadian hydro or emerging long-duration storage.
Who This Affects
- Utility planner (MA/CT/RI/VT): The 1.2-GW line’s regional cost allocation means your rate base absorbs a share of transmission revenue requirements starting when the line energizes; model the tariff impact now to avoid 2029 rate-case surprises.
- Onshore wind developer: King Pine’s 400-MW headroom on the line creates a de facto “open season” for adjacent projects; secure interconnection queue position and land rights in Aroostook before the next ISO-NE cluster study closes.
- Grid operator (ISO-NE): Winter reliability models must now incorporate 800 MW of firm-ish wind with a 35-40 percent capacity factor in January; recalculate oil-displacement benefits and reserve margins for the 2028/29 capacity auction.
- Policy analyst (state energy offices): The bifurcated cost structure – socialized wires, contracted energy – becomes the template for future multi-state procurements; draft legislation or rulemakings to codify the allocation methodology before the next solicitation cycle.
- Investor in transmission infrastructure: Avangrid’s regulated-return model on the line (likely 9.9-10.5 percent ROE under ISO-NE tariff) offers a lower-risk counterpart to merchant offshore equity; watch for Avangrid’s next earnings call for capital-expenditure phasing and AFUDC assumptions.
What to Watch Next
- ISO-NE’s final interconnection study results for King Pine Transmission (expected Q3 2025) – any thermal or stability upgrades required at the Pittsfield tie-point will shift the in-service date and cost allocation.
- Massachusetts and Connecticut DPU/DEEP approval of the long-term power purchase agreements – the contracts must clear state cost-effectiveness tests that now include the regionalized transmission adder.
- FERC action on any complaint regarding the multi-state cost allocation – a single-state objection could trigger a Section 206 proceeding that delays tariff implementation by 12-18 months.
- Clearway’s final investment decision and turbine procurement announcement – supply-chain lead times for 6-7 MW class onshore turbines currently run 18-24 months; a 2025 FID is needed to hit the 2028 partial COD target.
Bottom line: The King Pine pairing converts Northern Maine’s stranded wind resource into a fungible, regionally priced asset that directly attacks New England’s two most intractable problems – winter fuel security and retail rate shock – while offshore wind remains stuck in federal review. If the cost-sharing holds and the line energizes on schedule, it becomes the proof-of-concept for a repeatable onshore transmission playbook that could unlock the next 3 GW sitting in ISO-NE’s queue.
Read the full report at Energy Central
Note: facts and figures attributed above to reflect that outlet's original reporting. Broader context, cross-sector connections, and forward-looking scenarios reflect independent analysis by our editorial team.
About this article: Drafted by Energy Ai with AI-assisted research and writing based on public reporting, then reviewed under our editorial process before publication.
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