Eversource Files $503 Million Connecticut Rate Case Seeking 11 Percent Increase as Attorney General Tong Publicly Opposes

Eversource opened a formal rate proceeding at the Connecticut Public Utilities Regulatory Authority on May 20, requesting a $503 million revenue increase that averages roughly 11 percent across customer classes. Within hours of the filing, Connecticut Attorney General William Tong issued a public statement opposing the hike. That sequence, a contested rate case in a state that has spent three years fighting its utility over delivery charges, sets the terms of a proceeding that will reshape commercial demand-charge economics across the Connecticut portion of ISO New England.

The filing. Eversource’s Connecticut Light and Power subsidiary serves roughly 1.3 million customers across most of the state outside the United Illuminating territory in southwestern Connecticut. The $503 million request, distributed across residential, commercial, and industrial classes at an 11 percent average, lands on top of a delivery-rate base that already drove the 2023 political confrontation between Eversource and the Lamont administration. Commercial and industrial customers, who pay separately metered demand charges as part of their delivery component, are the class most directly exposed to how PURA decides to apportion the increase.

The political fact. Attorney General Tong’s statement against the filing matters because it signals the procedural posture PURA will inherit. Connecticut’s Office of Consumer Counsel and the Attorney General are intervenors in every rate case, and a public position from the AG hours after filing telegraphs a contested, multi-round proceeding rather than a settlement. The 2023 PURA decision under former chair Marissa Gillett reduced Eversource’s previous request and restructured rate design components. The 2026 case will be decided by a reconstituted PURA, but the political environment that produced the 2023 outcome remains intact.

Why the rate-design question is the real story. PURA cannot approve a flat 11 percent hike across all components without making a rate-design choice. The increase has to land somewhere: customer charges, energy charges, demand charges, or capacity-related delivery components. In every recent Eversource Connecticut proceeding, the customer charge has been a battleground because flat fixed fees fall regressively on small consumers and erode the price signal for distributed energy. The same arithmetic applies inversely on the commercial side. If PURA pushes the increase into demand charges to maintain cost-causation logic, commercial customers with peaky loads, hospitals, retail anchors, refrigerated warehouses, see payback periods on on-site battery storage compress by months.

The Eversource service territory math. Connecticut’s commercial blended retail rate sits among the five highest in the contiguous United States, a function of structural ISO-NE supply scarcity, winter gas-pipeline constraints, and the legacy of stranded-cost recovery. Demand-charge components on Eversource Rate 30 and Rate 35 schedules, the standard medium and large commercial tariffs, already reach into the high teens per kilowatt-month during summer peak windows. An 11 percent delivery-side increase, partially absorbed into demand-charge components, would push peak demand pricing into a range that makes battery peak-shaving payback competitive with the four-year window commercial CFOs typically require for capital approval.

The ISO-NE backdrop. This proceeding does not sit in isolation. ISO New England spent $6 billion on three months of winter electricity in early 2026, the highest winter clearing in the region’s history. The capacity market redesign that replaces forward auctions with prompt seasonal procurement, effective this year, has raised capacity payments to resources that can deliver during peak windows. Behind-the-meter batteries dispatching against a commercial customer’s coincident-peak hour produce two compounding savings: avoided demand charge at the building meter and capacity credit at the ISO level, the latter now flowing through retail aggregator arrangements in eligible Connecticut territories. A higher delivery rate amplifies the first savings; the capacity market amplifies the second.

The precedent risk. If PURA approves the increase substantially as filed, Connecticut becomes the third New England state in 2026 with a major investor-owned utility commercial-rate restructuring. Massachusetts Eversource and National Grid have ongoing demand-side management cuts that the Maryland-Massachusetts-Rhode Island efficiency reductions documented in April. Maine’s Versant Power has a parallel C&I proceeding open at the Maine PUC. The regional pattern is consistent: delivery rates rising faster than energy rates, demand-side management programs contracting, capacity payments restructuring upward. Commercial customers in the region face a rate environment where on-site dispatchable load reduction has shifted from optional to economically determinative.

The political reality versus the math. Tong’s opposition does not change the underlying cost-of-service arithmetic. Eversource will document its capital expenditures, return on equity request, and revenue requirement. PURA will reduce the request, almost certainly, and restructure where the remaining increase lands. The question is not whether commercial customers will pay more. The question is whether they will pay more through fixed charges that storage cannot reduce or through demand charges that storage directly attacks. That allocation decision, made by three PURA commissioners over the next twelve months, determines whether the proceeding accelerates or slows commercial battery deployment in Hartford, Stamford, Bridgeport, New Haven, and Waterbury.

The capital cycle. Eversource’s filing arrives at the moment when PowerBank’s NYSERDA-incentivized lease financings for distributed storage in New York closed at the 60 MWh level, when Spearmint Energy closed $450 million for 600 MWh in Texas, and when commercial real-estate-secured project capital is reaching close in 30 to 45 days for FEOC-compliant developers. Connecticut’s commercial customers have lease and PPA structures available that did not exist in the previous Eversource rate cycle. The financing pipeline is no longer a constraint on whether a building owner converts an 11 percent rate increase into a peak-shaving capital project. The constraint is the rate-design decision PURA has not yet made.

A $503 million filing, a public Attorney General objection, a capacity market in transition, and an integrated commercial storage financing market all colliding in a single docket. Connecticut PURA will spend the next year deciding what the C&I rate base looks like in 2027. That decision will be read closely in Boston, Augusta, and Providence.

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