PURA hears competing flexible-interconnection plans from Eversource and United Illuminating; officials press on costs and developer risk

At a technical meeting of the Public Utilities Regulatory Authority, Eversource and United Illuminating laid out contrasting strategies to expand distributed energy resource (DER) hosting capacity through "flexible interconnection." Commissioner Jan Beecher opened the session noting the docket (25‑1‑27) and that the utilities' proposals were filed with the authority as motion 22 on March 16, 2026.

Eversource project manager Joseph Debs said his company lacks an enterprise DERMS today and therefore favors a scheduled flexible‑interconnection approach in the short term, using published, time‑varying curtailment schedules for developers while a centralized DERMS/ADMS is procured. "Based on that information, we felt that anything below 500 kilowatt with that cost base is not practical," Debs said, explaining the company’s $75,000‑plus gateway cost estimate and the rationale for a 500 kW threshold for requiring a gateway.

United Illuminating (UI) described a different route. UI staff proposed piloting real‑time, utility‑operated DER control that curtails resources only when necessary, and advanced a vintaging or pro‑rata allocation method so projects assigned to the same vintage share curtailment proportionally. As UI explained, "any of the projects that are assigned in that vintage, they get curtailed on a prorated basis," a structure UI said improves predictability for smaller projects compared with strict last‑in/first‑out queue treatment.

Why it matters: flexible interconnection is designed to allow more DERs to connect without immediate circuit or substation upgrades, but the choice between scheduled limits and real‑time utility control affects how much generation is enabled, how often projects are curtailed, what equipment developers must buy and how much cost is shifted to ratepayers.

Implementation and timing
Eversource estimated full flexible interconnection with a centralized DERMS would require PURA approval and roughly two years to reach operational status; it recommended scheduled interconnection as a 3–6 month interim path for many projects. UI said it could begin accepting flexible applications about seven months after approval for a pilot and estimated energized project timelines toward 15 months, but cautioned that policy and interconnection guidelines need further development before statewide rollout.

Cost and cost recovery
Both companies said project‑specific study and gateway costs (study fees, upgrades, developer gateway costs) would remain developer‑responsibility under current interconnection rules. Larger capital costs for DERM/ADMS systems, Eversource said, are typically recovered through non‑bypassable reconciling mechanisms (FMCC/RAM) between rate cases and could be folded into rate base at a later rate case. Chairman Weil pressed why such investments would not be included in regular rate base; Eversource's Michael Schallens explained past practice has allowed interim recovery through reconciling mechanisms when projects arise between rate cases.

Developer risk and bankability
Commissioners and stakeholder callers asked how increased curtailment risk affects developers' financing. Both utilities and developer representatives said answers are project‑specific. Noel Lafayette, speaking from a finance perspective, urged contractual certainty by modeling worst‑case and best‑case curtailment ranges so financiers can underwrite projects. Utilities said they aim to provide better data (including updated hosting‑capacity maps) but cautioned they cannot guarantee absolute curtailment certainty because of system variability outside their control.

Data access and transparency
Eversource said it updated hosting capacity maps on May 6 to include circuit, substation and time‑series headroom data for developers. UI said its map program is being upgraded and that the work group will need to balance developer information needs with customer confidentiality and system‑security concerns.

Next steps
EDCs proposed continuing the flexible‑interconnection work group at least through March 2027 to address late comments and harmonize approaches with affiliate territories; the parties scheduled a training session on the hosting‑capacity map and the first successor work group meeting for late June. PURA staff outlined procedural deadlines: interrogatories tentatively scheduled for June 10, 2026 with responses due June 24; a proposed final decision timeline leading to a tentative final order on Oct. 7, 2026.

Reporting boundaries: coverage here is based solely on arguments and factual statements made at the public technical meeting; cost figures and timelines reported are the utilities' estimates and were discussed at the session.