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VT — Power Infrastructure Updated 2026-01-08

Vermont

ISO-NE Solar Storage Transmission Constraints

Overview

Vermont’s power infrastructure story is one of small-scale renewable development and grid modernization. The state’s largest active generation project is a proposed 50 MW solar array in Panton, and the interconnection queue is dominated by solar and battery storage with no new fossil fuel or nuclear plants in the pipeline. VELCO, the state’s transmission operator, is upgrading aging substations and lines to maintain reliability as the grid transitions.

Generation Projects

Solar

Vermont’s active solar pipeline is led by three utility-scale projects in ISO-NE’s interconnection queue.

  • FPS Panton Solar (Addison County): 50 MW array on 300 acres near the Dead Creek Wildlife Area, proposed by Freepoint Solar and SunEast Development as Vermont’s largest solar project to date.[1][2]
  • Shaftsbury Solar (Bennington County): 20 MW project in the active queue.[2]
  • Fair Haven Solar (Rutland County): 20 MW project in the active queue.[2]

Nuclear

Vermont law requires General Assembly approval before the Public Utility Commission can issue a certificate of public good for any nuclear generating plant — a high procedural bar.[3] No active nuclear projects appear in the ISO-NE queue.[2]

Transmission and Grid

VELCO is modernizing Vermont’s transmission backbone with several substation and line upgrades.

  • Franklin County Line Upgrade: Rebuild of the Georgia-to-Highgate 115 kV line with new structures and right-of-way work currently in permitting and phased construction.[4]
  • Newport Substation: Replacement of aging 116/43.8 kV transformer with Spring 2025 construction target and Fall 2025 commissioning.[5]
  • Windsor Substation: Control building, protection, and containment upgrades with Spring 2025 construction target and Spring 2026 commissioning.[6]
  • Florence Substation (Bennington County): Equipment replacement at 115 kV/46 kV facility as part of VELCO’s ongoing asset modernization program.[7]
  • K24-5 Emergency Pole Replacement (Waterbury area): Upgrade work on 115 kV line with late-summer 2025 construction and completion.[8]

Battery Storage

Vermont has two utility-scale battery projects in active development and one recently commissioned.

  • South Street Storage (Middlebury): 2 MW / 8 MWh battery system energized in 2025 by Encore Renewable Energy, co-located with a 5 MW solar array.[9]
  • Two 19.3 MW battery projects in Windsor County and Franklin County are active in the ISO-NE queue but not yet in service.[2]

What to Watch

  • Whether the 50 MW Panton Solar project secures local approvals and advances through ISO-NE’s interconnection process.
  • VELCO’s 2026-2027 transmission upgrade timeline and any new substation capacity unlocked by these projects.
  • The two 19.3 MW battery storage projects’ progression from queue status to commercial operation.

Sources

[1] Sophia Thomas, “Backlash over Panton solar project plan,” WCAX, April 17, 2024, https://www.wcax.com/2024/04/17/backlash-over-panton-solar-project-plan/ (accessed 2026-01-08).

[2] ISO New England, “Public Queue” (IRTT interconnection request queue), https://irtt.iso-ne.com/reports/external (accessed 2026-01-08).

[3] Vermont Legislature, “30 V.S.A. § 248 (e)(1)” (certificate of public good; nuclear approval), https://legislature.vermont.gov/statutes/section/30/005/00248 (accessed 2026-01-08).

[4] Vermont Electric Power Company, “Franklin County Line Upgrade,” https://www.velco.com/projects/franklin-county-line-upgrade (accessed 2026-01-08).

[5] Vermont Electric Power Company, “Newport Substation,” https://www.velco.com/projects/newport-substation (accessed 2026-01-08).

[6] Vermont Electric Power Company, “Windsor Substation,” https://www.velco.com/projects/windsor-substation (accessed 2026-01-08).

[7] Vermont Electric Power Company, “Florence Substation,” https://www.velco.com/projects/florence-substation (accessed 2026-01-08).

[8] Vermont Electric Power Company, “K24-5 Emergency Pole Replacement Project,” https://www.velco.com/projects/k24-5-emergency-pole-replacement-project (accessed 2026-01-08).

[9] Billy Ludt, “Encore Renewable Energy completes 2-MW storage project at Vermont university,” Solar Power World, September 3, 2025, https://www.solarpowerworldonline.com/2025/09/encore-renewable-energy-completes-storage-project-for-vermont-university/ (accessed 2026-01-08).