CT — Power Infrastructure Updated 2026-07-17

Connecticut

ISO-NE Data Center PPAs

1) Grid operator and market structure

  • Grid operator / balancing authority: Connecticut is in ISO New England, the RTO/balancing-authority region covering Connecticut, Rhode Island, Massachusetts, New Hampshire, Vermont, and most of Maine. ISO New England, accessed 2026-07-17
  • Market structure: Connecticut restructured electricity in Public Act 98-28; customers may buy generation service from competitive suppliers while distribution remains regulated by PURA through Eversource and United Illuminating service territories. Connecticut Public Act 98-28, 1998

2) Interconnection queue (status, wait times, reforms)

  • ISO-NE generation/storage queue: ISO-NE’s standard interconnection queue is primarily for generation, storage, and transmission interconnections, so it does not directly measure most retail data-center load requests. ISO New England, accessed 2026-07-17
  • Large-load forecasting is now part of CELT 2026: ISO-NE’s May 1 final CELT report incorporates the 2026 large-load forecast. The supporting methodology uses transmission-owner surveys and includes projects of at least 20 MW that have entered formal study agreements. ISO New England 2026 CELT Report, 2026-05-01; ISO New England large-load forecast methodology, 2026-03-27
  • Connecticut-specific large-load signal: The final pre-publication project table feeding CELT 2026 listed only one Connecticut item, an 85 MW general electrification project through 2040; the only listed data-center load was a 200 MW project in the NEMA load zone, not Connecticut. ISO-NE then published the final CELT workbook on May 1. ISO New England large-load forecast methodology, 2026-03-27; ISO New England 2026 CELT Report, 2026-05-01
  • Near-term construction status: ISO-NE reported that none of the listed large-load projects were under construction, so the large-load forecast contribution for winter 2026/2027 and summer 2026 and 2027 was zero. ISO New England, 2026-03-27
  • Forecast uncertainty treatment: ISO-NE said data centers often receive heavier derates because of speculative project risk and applied a 70% capacity-utilization derate to data centers in the CELT 2026 methodology. ISO New England, 2026-03-27

3) Ratepayer protection (large-load tariffs, cost allocation, PURA actions)

  • No enacted Connecticut data-center large-load tariff: HB 5469 would have required PURA implementation proceedings, large-load tariffs, and financial guarantees for large electric load customers, but it died on the House calendar and did not create an enacted PURA mandate. Connecticut OLR HB 5469 bill analysis, 2026-04-07; Connecticut General Assembly HB 5469 bill status, 2026-04-07
  • HB 5469 framework: The bill defined a large electric load customer as a customer with peak demand of at least 50 MW, would have required co-located suppliers to license with PURA, and would have required large-load customers to contract for new generation covering anticipated load plus a reserve margin. Connecticut OLR HB 5469 bill analysis, 2026-04-07
  • Ratepayer focus: OFA’s fiscal note said HB 5469 had no state or municipal fiscal impact and could produce indeterminate ratepayer savings by helping ensure existing utility customers do not pay total costs related to interconnecting new large-load customers. Connecticut OFA fiscal note HB 5469, 2026-04-06
  • Utility testimony: United Illuminating told the Energy and Technology Committee that it already had an LPT-TRA tariff for large-load customers and was unsure whether HB 5469 would require a different tariff. Connecticut General Assembly Energy and Technology Committee HB 5469 JF report, 2026-03-30
  • Consumer-protection testimony: In SB 245 testimony summaries, the Office of Consumer Counsel recommended treating data centers as a distinct electric-consumer class, requiring financial guarantees and exit fees, and studying grid reliability, energy consumption, and water use impacts. Connecticut General Assembly Energy and Technology Committee SB 245 JF report, 2026-03-26
  • Eversource posture: Eversource’s CEO told analysts on the May 7, 2026 first-quarter earnings call that the company was resisting data centers because of expected energy-price effects, and CT Insider reported that Eversource’s system-planning lead viewed hyperscale loads of 100 MW or more as a serious Connecticut and regional grid concern even though the utility cannot voluntarily refuse service. Utility Dive, 2026-05-08; CT Insider, 2026-05-15
  • No new PURA large-load class or ruling: HB 5469’s failure left no state mandate to establish a new tariff, and a review of PURA’s active electric dockets found no data-center-specific large-load tariff or cost-allocation proceeding as of July 17. United Illuminating’s existing LPT-TRA service therefore remains the only large-load tariff specifically identified in the 2026 legislative record. Connecticut General Assembly HB 5469 bill status, 2026-04-07; Connecticut PURA active electric docket database, accessed 2026-07-17; Connecticut General Assembly Energy and Technology Committee HB 5469 JF report, 2026-03-30
  • FERC opened a regional tariff case, but no new rule was yet effective: On June 18, FERC opened Docket EL26-72 and preliminarily found ISO-NE’s tariff potentially unjust or unreasonable because it lacks sufficiently clear large-load definitions, study and operating requirements, network-upgrade cost transparency, cost-recovery agreements, financial security, and tailored co-location/electrically-proximate-load provisions. ISO-NE and participating transmission owners were ordered to justify the existing tariff or propose changes within 60 days, and ISO-NE was ordered to file a resource-adequacy report within 30 days. Both filings were still pending as of July 17. Federal Energy Regulatory Commission Order, 195 FERC ¶ 61,215, 2026-06-18
  • Regional state coordination: On July 1, Connecticut and the other five New England states committed through NESCOE to collaborate with ISO-NE, consumer advocates, and stakeholders on large-load integration, infrastructure cost allocation, reliability, and consumer protection, recognizing that a large load in one state can affect all six. New England States Committee on Electricity, 2026-07-01

4) Generation adequacy (planned projects, storage, shortfall concerns)

  • Regional context: ISO-NE told New England senators on February 6, 2026 that New England hosts several small data centers but no new large data centers or other large electrification projects had committed to construction at that time. ISO New England, 2026-02-06
  • Data centers not yet a regional wholesale-cost driver: ISO-NE said data centers had not been a driving factor in New England wholesale electricity costs to date because the region had not seen significant data-center development. ISO New England, 2026-02-06
  • Adequacy risk remains forward-looking: ISO-NE also warned that New England’s surplus capacity could decrease if demand growth increases or existing resources retire early, and it highlighted winter fuel constraints as a continuing regional challenge. ISO New England, 2026-02-06
  • Transmission-cost backdrop: DEEP’s Transmission Solutions White Paper says annual transmission costs have grown 72% since 2015 and now represent 10-11% of a typical Connecticut residential monthly electric bill, making large-load cost allocation a material policy issue even before major data-center load arrives. Connecticut DEEP Transmission Solutions White Paper, 2025-02-26

5) Utility load forecasts / IRP filings (data center demand)

6) Behind-the-meter / co-location / direct PPAs

  • State bill did not pass: HB 5469 was Connecticut’s main 2026 co-location bill; it would have licensed co-located electric suppliers serving large load customers behind the meter or off-grid and required new generation to cover load plus reserves, but it was not enacted. Connecticut OLR HB 5469 bill analysis, 2026-04-07; Connecticut General Assembly HB 5469 bill status, 2026-04-07
  • Bristol project signal: Bristol’s mayor described the proposed Riverside Avenue facility as bringing its own 4 MW on-site fuel-cell power and avoiding grid/ratepayer impacts, with closed-loop cooling and no river withdrawal or discharge. The mayor also clarified that the Connecticut Siting Council’s approval applies to the fuel-cell installation, not to the locally reviewed data-center building. City of Bristol Mayor’s Office, 2026-04-22
  • Colchester project signal: ReNew’s marketed Old Amston Road site contemplates a 5 MW first phase and an 18 MW second fuel-cell phase (up to 23 MW total), but the developer states that the data-center buyer must still obtain building permits; it is therefore not an operating or committed load. ReNew Developers Old Amston project page, accessed 2026-07-17
  • FuelCell Energy product strategy: FuelCell Energy introduced standardized 12.5 MW on-site power blocks for data-center customers and said it planned to expand Torrington manufacturing capacity from about 100 MW to 350 MW to meet expected data-center demand. FuelCell Energy, 2026-03-23
  • FuelCell Energy expansion update: On June 8, 2026, FuelCell Energy said it had increased the Torrington expansion target to an annualized production rate of up to 500 MW, with estimated total expansion cost of $200 million to $275 million over about 24 months. FuelCell Energy, 2026-06-08

7) Transmission constraints and upgrades

  • Large-load process has moved to a federal show-cause proceeding: ISO-NE’s May 20 NECPUC presentation anticipated federal guidance; FERC followed on June 18 with Docket EL26-72, requiring ISO-NE and the transmission owners to address large-load study procedures, upgrade-cost transparency, financial security, cost recovery, co-location, and operating requirements. The order did not itself select a replacement tariff. ISO New England, 2026-05-20; Federal Energy Regulatory Commission Order, 195 FERC ¶ 61,215, 2026-06-18
  • Transmission planning cost exposure: DEEP’s 2025 white paper emphasizes rigorous review of regional transmission proposals and advanced transmission technologies as cost-containment strategies for Connecticut ratepayers. Connecticut DEEP Transmission Solutions White Paper, 2025-02-26
  • Current Connecticut data-center load is not yet driving ISO-NE transmission additions: ISO-NE’s 2026 large-load materials list no Connecticut data-center project in the included table and no listed large-load project under construction for the immediate 2026/2027 periods. ISO New England large-load forecast methodology, 2026-03-27

Source notes (primary sources prioritized)

  • Connecticut General Assembly: HB 5469 bill analysis, fiscal note, bill status, and committee report.
  • ISO New England and FERC: February/March 2026 forecast materials, the final May 2026 CELT workbook, the May NECPUC presentation, and the June 18 FERC show-cause order.
  • CT DEEP: Integrated Resources Plan page and Transmission Solutions White Paper.
  • Utility/project/local sources: Eversource reporting, Bristol mayoral update, and FuelCell Energy company releases.