Transmission into Savings: Better Connection for Better Rates?

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Maine has abundant potential to generate affordable electricity from renewable sources, but producing electricity and delivering it to the people who need it are two different things. A wind farm in northern Maine cannot do much for a household in southern Maine or New England if the transmission system cannot carry its power to market. Done well, transmission lines can make new energy projects possible, improve the reliability of the electric grid and reduce the prices consumers pay. Done poorly, they can impose costs on ratepayers, damage landscapes and leave communities feeling that decisions have been made somewhere else.

Those competing possibilities framed an E2Tech discussion titled “Transmission into $avings: Better Connection for Better Rates?” The panel brought together ISO New England’s Melissa Winne, Maine Public Utilities Commission (PUC)’s Carrie Gilbert, Maine Office of the Public Advocate’s Heather Sanborn, Natural Resources Council of Maine’s Jack Shapiro, and RLC Engineering’s Rick Conant with moderator Jeff Thaler of Preti Flaherty.

The conversation was notable for its broad agreement on the need to think regionally about the electric grid—and its insistence that the details will determine whether the promised benefits materialize. (Click here for slides from the event. This program continues the discussions started in E2Tech's previous GRIDsilience panel which gave an overview of energy storage, grid upgrades, and ISO New England's Longer-Term Transmission Planning (LTTP) RFP.)

The grid is a regional system

Melissa Winne, ISO New England’s lead state policy advisor, described a transmission system that has to be planned decades in advance. The region operates roughly 9,000 miles of high-voltage transmission lines, connecting power plants, substations and communities across six states. The system was largely built around an older pattern of electricity generation and consumption. Today, planners must account for changing electricity demand, aging infrastructure, new sources of generation and the prospect of a much more electrified economy.

ISO New England’s longer-term planning process looks toward the needs of the region through 2050. Its first major long-term transmission study was published in 2024. The following year, the organization solicited proposals for regional upgrades and the selected proposal from Central Maine Power and Eversource calls for approximately $2.2 billion in transmission improvements, primarily rebuilding infrastructure within existing rights of way. The project is planned to enter service in the fourth quarter of 2032.

The projected benefit-cost ratio is 2.1, meaning the estimated benefits are more than twice the anticipated costs. Those benefits depend on regional modeling and assumptions about how the electric system will evolve, rather than on a single new power plant or a single customer’s bill. The costs would be shared among the six New England states according to their peak electricity demand. Based on 2025 figures, Maine’s share would be about 9 percent.

Northern Maine’s wind opportunity

Carrie Gilbert of the Maine Public Utilities Commission discussed a second proposed transmission line associated with an 800-megawatt wind project in Aroostook County. On September 4, the PUC awarded a power purchase agreement for the wind project and recommended a transmission line to help deliver its electricity. Under the arrangement, Maine would take 600 megawatts of the project’s output, with participating states sharing the remainder. Five of the six New England states would participate in the transmission costs. Maine’s share of the northern line’s cost would be just under 11 percent, though Maine would benefit from 75% of the power generated.

Combined, these projects are expected to create more than 2,500 full-time jobs and generate $2.4 billion in economic activity statewide. The proposal is projected to generate approximately $400 million in net benefits for Maine ratepayers. It is also expected to reduce expensive oil-fired electricity generation by about 10 percent.

The financial case rests on more than the price paid for the wind power itself. Additional electricity supply can change the economics of the regional wholesale market. When lower-cost generation displaces more expensive sources, prices can fall for consumers beyond those buying the new project’s electricity directly. This is known as price suppression. It is one reason a transmission project can create value across a region, even when the generating facility is located in a single state.

But the proposal is not a finished project. Contracts, interconnection studies, permitting and a certificate of public convenience and necessity remain important steps. The projected savings are an argument for moving forward with careful analysis, not a guarantee that every anticipated benefit will appear.

Protecting ratepayers

Heather Sanborn of the Office of the Public Advocate approached the proposals from the perspective of electricity customers. For ratepayers, the question is not simply whether transmission is needed. It is whether a particular investment delivers benefits commensurate with its cost and whether the people paying for it receive a fair share of those benefits. The regional grid is full of examples of why the answer can be complicated. Transmission constraints can prevent lower-cost electricity from reaching customers who need it. At other times, congestion can contribute to unusual market conditions, including negative wholesale prices in some locations.

New transmission can relieve those constraints and allow electricity to move more freely. Yet the outcome depends on the system as a whole: where power is generated, where demand occurs, what other plants are operating and how the market responds. Sanborn pointed to the broader experience of the New England Clean Energy Connect (NECEC) project, the transmission line built to bring Canadian hydropower into the region. Massachusetts was responsible for the costs under its arrangement, while the effects on electricity prices have benefited Maine. Maine's day-ahead price averaged $7/MWh below the rest of ISO-NE when NECEC was online on summer days, against $1/MWh below when it was offline.

The environmental case necessitates detailed scrutiny and local engagement

Jack Shapiro of the Natural Resources Council of Maine supported the general logic of developing clean energy and the transmission infrastructure needed to deliver it. But he cautioned against treating the environmental benefits of renewable electricity as a reason to set aside the environmental consequences of upgrading the grid. At this early stage, important details about routes, turbines and substations were not settled. Those details will shape the impact on wetlands, farmland, viewsheds and nearby communities.

For Shapiro, regional planning and environmental review need to work together. A project may provide meaningful climate benefits while still creating avoidable local damage. Early engagement with communities can help identify those conflicts before plans become too advanced or expensive to change. He also pointed to community-benefit agreements as one way to address the relationship between infrastructure projects and the places that host them. Such agreements do not eliminate disagreement, but they can give communities a clearer understanding of what a project will mean for them and what commitments developers are prepared to make. The distinction is important. A regional model may show that a line is economically valuable, but that model cannot settle every question about a particular road crossing, wetland or neighborhood. Those questions require local knowledge and a transparent process.

Building big things is not easy 

Rick Conant, founder of RLC Engineering and a veteran of the industry with over 30 years of experience in the electric utility industry, brought a practical perspective to the discussion. The panel’s broad agreement about the value of transmission upgrades was itself striking, he suggested, given how often energy infrastructure becomes politically contentious.

Conant also emphasized that the benefits of upgrading the grid extend beyond the particular renewable energy projects that may use it. Replacing aging equipment and improving existing transmission infrastructure can strengthen long-term reliability. Much of the proposed regional work would rebuild lines within existing rights of way. That can reduce the need to acquire entirely new corridors, although it does not mean the construction will be invisible. Structures can vary in height, with some taller poles required in particular locations.

Even when the engineering and economics make sense, permitting can be a major source of uncertainty. Projects must navigate state and federal requirements as well as local land-use rules. Towns may have different priorities, and local moratoria or other restrictions can complicate the path forward. Conant cited the Northern Pass transmission proposal in New Hampshire as a reminder that hundreds of millions of dollars spent on planning and permitting work does not guarantee approval. A project can spend years advancing before encountering political and local opposition that ultimately prevents it from proceeding.

Transmission infrastructure is not an especially glamorous part of the energy transition. Yet the grid determines what resources can serve customers efficiently and whether the investments made in generation translate into lower costs and greater reliability. As Maine and the rest of New England prepare for changing electricity demand and a more diverse generation mix, the challenge is to build the infrastructure that will make the region's energy resources useful, affordable and reliable — while earning the public confidence necessary to get the work done.

Special thanks to event sponsors Preti Flaherty, Cianbro and Western Maine Energy Storage. ⁠E2Tech programs are supported by our members and sustaining partners like the Maine Technology Institute which offers grants, loans, equity investments, and services to foster Maine’s innovation economy.