Earnings posted by electric utilities are drawing attention from customers, advocacy organisations, and oversight bodies — a pattern playing out in Maine as elsewhere. Power companies have put forward the case that sustaining their current rate of return is necessary to draw in capital for grid upkeep, particularly given the added strain that shifting weather patterns place on energy infrastructure.
Utility providers holding exclusive rights over their service territories operate under rules that cap the financial returns allowed on their capital outlays. Settling on an acceptable level of earnings can draw out negotiations and legal proceedings for months or even years.
A rate filing from Central Maine Power — one that would lift the company's allowed return on equity — has drawn considerable attention throughout the year. While regulators weigh that pending application, a separate layer of rate-related rulemaking has been taking shape away from public view.
Regulators at both the state and federal levels have moved to place caps on what utilities can earn from electricity transmission. A ruling from the Federal Energy Regulatory Commission, handed down earlier this year, directed transmission utilities across New England to return over $1.5 billion to ratepayers after a review determined that the profit margins those companies had been permitted to collect were pegged at levels above what the commission considered appropriate. Legal proceedings remain active as the utility companies contest the matter.
State regulators in Maine petitioned a federal body to eliminate an incentive that had also expanded profit opportunities for utility companies — a move that prompted several of those firms to file lawsuits against the state.
Strung between generating facilities — whether conventional power plants or renewable wind and solar installations — and neighbourhood-level substations, high-tension transmission lines move electrical power across the distances that often separate those two points. From that junction, a finer lattice of distribution lines fans outward, carrying power to homes, businesses, and wherever else demand calls for it.
Oversight of the transmission network falls to the Federal Energy Regulatory Commission because it spans multiple states, whereas Maine's own distribution infrastructure answers to the Maine Public Utilities Commission. Three entities hold transmission ownership across Maine — Central Maine Power, Versant, and the Maine Electric Power Company, a joint venture the two utilities operate together. Two separate utilities divide Maine's territory: one handling the southern and central regions, the other responsible for the eastern and northern portions — operated by Central Maine Power and Versant, respectively. A transmission corridor operated by Maine Electric Power Company links the state of Maine to the Canadian province of New Brunswick.
A formal complaint lodged with the Federal Energy Regulatory Commission in 2011 — filed by the Maine Office of the Public Advocate alongside other groups representing utility customers — challenged the 11.14% return on equity that New England transmission line owners had been permitted to collect, arguing the rate exceeded what could be reasonably justified. Utility shareholders earn a return on equity — a share of company profits tied to the capital they put in — that funds the construction and upkeep of power and water infrastructure.
Following a drawn-out dispute spanning multiple rounds of review, the Federal Energy Regulatory Commission put out a ruling in March of this year that upheld its prior determination, setting the permitted return on equity at 9.57%. Transmission line owners were directed to apply retroactive refunds covering the pricing gap, with those payments reaching customers no later than May 2027.
Roughly $130 million of that $1.5 billion pool is set aside for Maine-based customers to receive back. Heather Sanborn, who holds the Maine public advocate post, put the likely benefit for a typical home customer at around $20 each month across a 12-month span. Additional data from the corporate sources involved would be needed to sharpen any estimate, she noted.
A June ruling by the Federal Energy Regulatory Commission drew a formal appeal from Central Maine Power, Versant, and other transmission owners operating across New England. Versant put forward a refund proposal the following month, with ISO New England overseeing the process and the plan now sitting before FERC pending a decision on whether to grant it. Further details are expected to become available once FERC hands down its ruling.
In an emailed statement, Versant spokesperson Marissa McKay noted that the matter pertains exclusively to transmission customers within the company's Bangor Hydro District, leaving Maine Public District customers unaffected. The spokesperson left open how the company's involvement in the appeal might bear on the refund timeline, then noted that while legal proceedings are ongoing no comment was possible, and that the company's efforts remain directed toward getting customers their money back, pending FERC's sign-off on the proposal. No comment on the active lawsuit was forthcoming from Central Maine Power.
Legislation enacted by Maine's lawmakers in 2025 obligated the state's utility providers to join ISO New England, the regional body overseeing electricity transmission. In handing over that authority, the utilities cede day-to-day command of their transmission networks to ISO New England, which then coordinates and directs grid operations across the region. Membership in ISO New England had been voluntary for those utilities, which collected a 0.5% adder on top of their authorised return on equity as a financial reward for taking part.
Three Maine agencies — the Office of the Public Advocate, the Public Utilities Commission, and the Department of Energy Resources — jointly brought a formal complaint before the Federal Energy Regulatory Commission, arguing that a particular rate adder has lost its justification now that utilities face a mandatory requirement to participate in ISO New England. Projections from ratepayer advocacy groups put the annual savings for Maine electricity customers at over $2 million. Versant has put forward no challenge to Maine's petition for removal of the adder.
A lawsuit filed by Central Maine Power and the Maine Electric Power Company is now before a judge, seeking to have the recently passed legislation declared unconstitutional and to prevent Sanborn, Philip Bartlett, and Celina Cunningham — the three state agency heads named in the action — from carrying out its provisions. The companies contend that Maine has overstepped into territory governed by federal authority, asserting in their court filing that the legislation was enacted solely to alter a rate that falls under the jurisdiction of the Federal Energy Regulatory Commission; they further stated that the regulation's financial consequences are considerable, materially undermining their capacity to achieve the return on equity to which they are entitled and upon which they depend for the investment capital needed to maintain and improve transmission infrastructure, preserve system reliability, and sustain the contractual foundation of their relationship with ISO-NE.
According to a recent Office of the Public Advocate analysis, what Maine ratepayers actually pay encompasses far more than transmission line costs, with the full combined total running about 72% above where it stood six years ago. Monthly bills for Central Maine Power customers climbed from roughly $91 to $157 between October 2020 and October 2026, a jump that Sanborn attributed to a range of overlapping factors rather than any single cause, noting that transmission costs tied to aging infrastructure replacement actually rank among the smaller contributors to the rate increases.
Among the variables shaping electricity bills, charges tied to maintaining and repairing the grid — including those stemming from weather-related damage — tend to carry the most weight. Natural gas prices stand out as the primary force pushing electricity costs upward. Growing adoption of heat pumps, electric vehicles, and similar technologies is projected to push power consumption higher. Shifts in weather patterns tied to a changing climate are placing growing pressure on the infrastructure that keeps the power grid running.
Sanborn's preferred path to keeping power affordable while maintaining a grid capable of meeting demand centres on spreading consumption more evenly across hours and seasons, so that the infrastructure built for distribution, transmission, and supply does not have to be sized entirely around the brief windows when usage peaks. Expanding battery storage capacity as additional renewable generation enters the grid can reduce pressure on the network and avoid the cycle of continuous infrastructure construction, Sanborn noted, while also pointing to the voluntary time-of-use pricing options available through both Central Maine Power and Versant as a way to shift customer demand toward off-peak hours — with the underlying aim, in her words, being to draw greater value from existing infrastructure by spreading consumption across more kilowatt hours throughout the year and thereby putting downward pressure on rates.
