New England's NECEC hydropower line delivers mixed early results after six months

The New England Clean Energy Connect transmission line began carrying hydropower from Canada into Maine in January 2024 to considerable fanfare. Nearly six months into operations, early performance data reviewed by climate nonprofit Acadia Center raises serious questions about whether the line will deliver the clean energy benefits its backers promised.

Energy flow falls short of expectations

Power flowing into New England via NECEC has increased only marginally since the line came online, according to Acadia Center. More strikingly, the line transmitted no electricity at all on roughly 27 days during that period.

If current trends continue, the region will import less hydropower this year across two transmission lines than it received over a single line in 2023 and earlier years, the nonprofit found. That outcome would represent a significant gap between the project's stated ambitions and its actual contribution to the regional grid.

What we've seen so far is not what some people expected to see. — Joseph LaRusso, manager of the Clean Grid Program, Acadia Center

Contract provisions protect ratepayers — for now

Despite the operational shortfalls, Massachusetts electricity customers carry limited direct financial risk, LaRusso said. The state's power purchase agreement with Hydro-Québec contains explicit penalty clauses tied to delivery obligations.

To the extent that imports are curtailed, Hydro-Québec is liable to make the electric utilities whole for the cost of replacement power. — Joseph LaRusso, manager of the Clean Grid Program, Acadia Center

The longer-term question of whether NECEC will meaningfully expand Massachusetts' renewable energy supply over time remains open, according to Acadia Center's analysis.

A brief glimpse of what full integration could look like

On May 16, conditions briefly aligned to illustrate NECEC's potential ceiling. Solar generation was high, suppressing grid demand, and the transmission line ran at full capacity — sending surplus power toward New York while natural gas plants operated at minimal levels.

For a short window, all of New England's power needs could be met entirely by non-fossil-fuel resources, LaRusso noted. The moment served as a proof of concept, even if it has not yet become a regular occurrence.

Hypothetically, ISO New England could've turned off its gas generators. It really gets you thinking of the resources available and how they could be managed and shared in the future. — Joseph LaRusso, manager of the Clean Grid Program, Acadia Center

What industry stakeholders should watch

For grid operators, utilities, and energy policymakers, NECEC's early record highlights the gap between transmission capacity investment and actual dispatch performance. The line's underutilization also reinforces broader industry debates about how cross-border transmission agreements are structured and enforced.

Acadia Center's analysis does not conclude that NECEC is a failed project, but it signals that the path from new infrastructure to measurable clean energy progress is neither automatic nor immediate. Ongoing monitoring of flow data and Hydro-Québec's contractual compliance will be critical benchmarks in the months ahead.