New England States Back Maine's Fight Against ISO-NE Membership Bonus
A multi-state push to strip transmission owners of their 0.5% RTO adder targets a payout embedded in the region's grid planning process.
Maine's complaint against the ISO New England membership bonus has drawn backing from other New England states, widening a fight over a 0.5% return on equity adder that transmission owners collect for voluntary RTO membership. The dispute lands at FERC as the region absorbs EIA data showing New England natural gas prices at Algonquin Citygate trading near record discounts to Henry Hub through the summer.5,3
The adder sits inside the same transmission planning machinery that ratepayer advocates say has skewed project selection in New England. NESCOE told federal regulators on Monday (2026-06-01) that Eversource Energy's X-178 project in New Hampshire "epitomizes" the need to reform the region's "asset condition" review process. The ratepayer advocates contend Eversource misclassified the $360.6 million project to avoid regulatory scrutiny.1
The numbers behind that argument are substantial. Since 2016, $6.5 billion in asset condition projects have been installed in New England, comprising 55% of all transmission projects, according to NESCOE.1 Looking ahead, $5.5 billion of asset condition projects are planned, proposed or under construction, against just $281 million in regional projects.1 Asset condition work flows through a lighter review track than regional projects — that disparity is the crux of the complaint.
Eversource rejects the framing. The utility said X-178 has been "extensively reviewed" in the ISO-NE PAC process, that it followed ISO-NE's rules in planning the project, and that the ratepayer advocates failed to identify any rule it violated.1 Eversource also rejected allegations it sought to "goldplate" the project, saying complainants identify no evidence that project scope, design or timing was influenced by compensation.1 Process compliance as proof of prudence is the standard utility defense.
Maryland ran a parallel case against PJM. State agencies asked FERC during the week of 2026-06-29 to strip Exelon and FirstEnergy utility subsidiaries, as well as a NextEra Energy unit, of the extra 0.5% return on equity they earn for voluntary PJM membership.3 Jefferies equity analysts said in a client note on Monday (2026-06-29) that the complaint will likely succeed given precedent set in California and Ohio.3 If that read holds, the ISO-NE case inherits a favorable template.
The timing sits awkwardly against New England's supply picture. Natural gas consumption from April through July 2026 ran 5% below the same period in 2025, according to S&P Global Energy data, while net Canadian flows into New England averaged a record 0.4 Bcf/d over the same window, more than 2.5 times the year-earlier volume.5 EIA's Hourly Electricity Grid Monitor shows gas-fired generation down 1.1 BkWh, or 6%, over the same period, with wind up 0.7 BkWh (59%) and utility-scale solar up 0.2 BkWh (29%).5 Weaker gas burn and record Canadian imports drove Algonquin to those record discounts.5
Cheap gas does not repeal the transmission bill. The adder is a return-on-equity kicker, not a fuel charge, so it shows up in rates regardless of where Algonquin trades. This is a cost-allocation fight, not a supply fight.
Broader FERC posture cuts both ways. The commission voted unanimously on 2026-06-18 to issue tailored show-cause orders under Section 206 of the Federal Power Act to all six RTOs and ISOs, directing each to justify or rewrite its large-load tariff.2 That signals appetite for re-examining RTO rules, but it also signals that FERC prefers to force the RTOs to act rather than impose outcomes itself. Whether the same posture extends to membership adders remains untested.
Elsewhere in the region, regulators on Tuesday (2026-08-25) moved Maine's long-stalled utility-scale wind ambitions closer to reality by selecting a developer, a process that had run for nearly two decades.4 New England's generation mix is shifting, and the wires that connect it are priced through processes now under challenge.
The region's carbon architecture adds another layer. RGGI states have cut power-sector emissions by half since the program's inception, raising more than $10 billion for energy programs, with emissions falling from a peak of 117.5 million short tons in 2010 to 61.9 million short tons in 2020.6 In 2007, coal accounted for 15% of generation in those seven states; as of 2026-09-16, no coal plants operate in any of them.6 A cap-and-trade rethink is under active discussion, adding cost uncertainty for the same ratepayers footing transmission bills.6
The transmission adder is not a traded instrument. But it feeds rate-case outcomes, which feed utility capital plans, which feed demand for the equipment and fuel behind New England's grid. How FERC handles the Maine complaint against the PJM precedent is the next concrete signal — if the California and Ohio cases carry the weight Jefferies assigns them, the ISO-NE adder faces the same fate; if FERC defers to the RTOs, the fight moves to state rate cases, where the $5.5 billion pipeline of asset condition projects gets defended project by project.3,1