Maine Governor Janet Mills vetoed a bill that would have halted the construction of large data centers in the state for 18 months. The state Legislature passed the measure last Tuesday, making it the first data center moratorium in the nation to successfully pass both chambers of a state legislature.

The bill, sponsored by State Rep. Melanie Sachs, would have prevented the construction of any data center requiring more than 20 megawatts of power for 18 months. Mills attempted but failed to secure an exception for a data center project in Jay, Maine.

"I believe it necessary and important to examine and plan for the potential impacts of large-scale data centers in Maine, as the use of artificial intelligence becomes more widespread," Mills said in a press release. She said she vetoed the bill because it did not include an exception for the Jay project.

"This project — which is now under contract and which has received several permits — is expected to create more than 800 construction jobs, at least 100 high-paying permanent jobs, and would contribute property tax revenue to the Town of Jay," Mills said in the press release. A paper mill closure in Jay in 2023 wiped out several hundred jobs. In an earlier interview, Mills said she was reviewing the bill carefully and was hesitant because it did not include a carveout for the Jay project, which she said needed an economic boost.

Mills, a two-term governor, is running for the U.S. Senate and is competing in a primary race with Graham Platner. Platner said in an interview that he believes Mills should sign the bill.

Data centers provide the computing infrastructure needed to power AI systems and cloud-computing services. Data center bans have been proposed in New York, Oklahoma and Georgia. Senator Bernie Sanders and Representative Alexandria Ocasio-Cortez proposed a federal moratorium on new data centers in late March.

A December 2024 Department of Energy study found that data centers consumed 4.4% of the U.S. energy supply in 2023 and projected that the share could rise to 12% by 2028. The global artificial intelligence industry is projected to spend nearly $3 trillion on data centers and related infrastructure through 2028.