In April, Gov. Janet Mills, Maine’s term-limited, outgoing governor, vetoed a bill that would have paused essentially all data center development across the state.

Mills said she vetoed the measure, LD 307, because it did not carve out an exception for a proposed $550 million center at the former Androscoggin Mill in Jay. The data center had strong support from the surrounding community, she wrote, and would “promote reinvestment and job creation at the former mill.” That claim was disputed by some fellow Democrats, who nearly unanimously supported the moratorium in the Maine Legislature.

Then, in early June, Sentinel Data Centers, the developer behind the Jay project, pulled its support anyway.

Data centers, which store data and run online applications and services, including artificial intelligence, have existed for decades but have taken on new significance in light of the AI boom and increased demand for computing power.

With the Androscoggin Mill data center “on hold,” a state council set to release a report on the impacts of the centers by next year and Mills leaving the Blaine House in January, the Portland Press Herald asked each major gubernatorial candidate whether he or she would sign the same bill that Mills vetoed, if the Legislature passed it again.

Here’s what they said.

HANNAH PINGREE

The clear front-runner in the race for the Blaine House, Democrat Hannah Pingree, broke with Mills — whose administration she worked in for more than six years — and said she would have signed the moratorium if she were governor.

She said she was especially concerned about the potential for negative health and environmental impacts. Data centers have become known for their telltale, high-pitched whir, and they require huge quantities of water to keep the computers inside cool. A 100-megawatt data center uses about 2 million liters of water — or just shy of an Olympic swimming pool’s worth — every day, just for cooling.

Pingree had previously expressed support for the moratorium in a primary debate hosted by Midcoast Villager. She said the state needed to pass environmental regulations around data centers, and rules forcing the centers to produce their own energy.

“We’ve seen what’s happened in Virginia and Texas, where people are paying way more for electricity because of AI data centers,” Pingree said. “I think we need some of the strongest laws in the country to make sure Maine communities are protected.”

BOBBY CHARLES

Bobby Charles, the Leeds lawyer and Republican nominee for governor, also said he would sign a moratorium on new data centers.

“I would sign a temporary moratorium on data centers until more is understood about their potential impact on both electricity draw … AND their impact on water use and impact on rivers in Maine,” Charles said in a written statement. In the statement, he also criticized Mills and Pingree for leaving in place an “under-capitalized power grid.”

Data centers use massive amounts of electricity; in 2023, the centers used 176 terawatt-hours, or about 4.4% of the nation’s electricity consumption, a May report from the Congressional Research Service said. That number was expected to at least double by 2028.

Charles, who often uses artificial intelligence in his social media posts, recently said he would not accept campaign contributions from those proposing data centers in Maine. In a news release this month, he called himself a “conservationist” and said he “has serious concerns about the impact large-scale AI data centers could have on Maine’s environment, and communities.”

RICK BENNETT

Bennett, an unenrolled state Senate member from Oxford County, voted in favor of LD 307 in the Legislature. He said he would sign a similar moratorium.

He said the state “needs to take the time to thoughtfully develop rules around data centers, as they can negatively affect shared resources like water and electricity.”

He also seemed to criticize how Mills handled the bill as it moved through the Legislature.

“I will engage early in the process, to make sure issues are addressed appropriately before they reach my desk,” Bennett said in a written statement. “I believe government works best when it listens to communities and solves problems honestly, not when leaders hide behind politics or think about the next election.”

In lieu of a statewide moratorium, several communities have enacted their own. In Sanford, for instance, local officials approved a 91-day moratorium in May, pausing a proposal for a 1,000-acre center along the Mousam River.