Even as the federal government attempts to prop up the waning coal industry, New England’s last coal-fired power plant has ceased operations three years ahead of its planned retirement date. The closure of the New Hampshire facility paves the way for its owner to press ahead with an initiative to transform the site into a clean energy complex including solar panels and battery storage systems.

“The end of coal is real, and it is here,” said Catherine Corkery, chapter director for Sierra Club New Hampshire. ​“We’re really excited about the next chapter.”

News of the closure came on the same day the Trump administration announced plans to resuscitate the coal sector by opening millions of acres of federal land to mining operations and investing $625 million in life-extending upgrades for coal plants. The administration had already released a blueprint for rolling back coal-related environmental regulations.

The announcement was the latest offensive in the administration’s pro-coal agenda. The federal government has twice extended the scheduled closure date of the coal-burning J.H. Campbell plant in Michigan, and U.S. Energy Secretary Chris Wright has declared it a mission of the administration to keep coal plants open, saying the facilities are needed to ensure grid reliability and lower prices.

However, the closure in New Hampshire — so far undisputed by the federal government — demonstrates that prolonging operations at some facilities just doesn’t make economic sense for their owners.

“Coal has been incredibly challenged in the New England market for over a decade,” said Dan Dolan, president of the New England Power Generators Association.

Merrimack Station, a 438-megawatt power plant, came online in the 1960s and provided baseload power to the New England region for decades. Gradually, though, natural gas — which is cheaper and more efficient — took over the regional market. In 2000, gas-fired plants generated less than 15% of the region’s electricity; last year, they produced more than half.

Additionally, solar power production accelerated from 2010 on, lowering demand on the grid during the day and creating more evening peaks. Coal plants take longer to ramp up production than other sources, and are therefore less economical for these shorter bursts of demand, Dolan said.

In recent years, Merrimack operated only a few weeks annually. In 2024, the plant generated just 0.22% of the region’s electricity. It wasn’t making enough money to justify continued operations, observers said.

The closure ​“is emblematic of the transition that has been occurring in the generation fleet in New England for many years,” Dolan said. ​“The combination of all those factors has meant that coal facilities are no longer economic in this market.”

Granite Shore Power, the plant’s owner, first announced its intention to shutter Merrimack in March 2024, following years of protests and legal wrangling by environmental advocates. The company pledged to cease coal-fired operations by 2028 to settle a lawsuit claiming that the facility was in violation of the federal Clean Water Act. The agreement included another commitment to shut down the company’s Schiller plant in Portsmouth, New Hampshire, by the end of 2025; this smaller plant can burn coal but hasn’t done so since 2020.

At the time, the company outlined a proposal to repurpose the 400-acre Merrimack site, just outside Concord, for clean energy projects, taking advantage of existing electric infrastructure to connect a 120-megawatt combined solar and battery storage system to the grid.

It is not yet clear whether changes in federal renewable energy policies will affect this vision. In a statement announcing the Merrimack closure, Granite Shore Power was less specific about its plans than it had been, saying, ​“We continue to consider all opportunities for redevelopment” of the site, but declining to follow up with more detail.

Still, advocates are looking ahead with optimism.

“This is progress — there’s no doubt the math is there,” Corkery said. ​“It is never over until it is over, but I am very hopeful.”