(Reuters) -NextEra Energy ( NEE/PU ) and Google have reached an agreement to restart an Iowa nuclear power plant shut five years ago, the companies said on Monday, in another sign that data-center power demand is renewing interest in U.S. nuclear energy.

The technology industry's quest for massive amounts of electricity for artificial-intelligence processing has renewed interest in the country's nuclear reactors, which generate large amounts of around-the-clock power that is virtually carbon free.

Under NextEra's deal with Google, the Duane Arnold Energy Center near Cedar Rapids is scheduled to resume operations in early 2029. The restart is backed by a 25-year agreement for Google to buy electricity from the 615-megawatt plant.

Shares of NextEra Energy ( NEE/PU ) rose over 1% to $87.24 after the bell.

The agreement follows a similar announcement at the former Three Mile Island nuclear power plant, which is owned by Constellation Energy, in Pennsylvania to fuel Microsoft data centers.

Google, Microsoft, Amazon and other so-called hyperscalers that operate massive cloud-computing infrastructure have also agreed in recent months to buy future energy produced by advanced nuclear technologies, including fusion and small modular reactors.

NextEra and Google also will explore the development of new nuclear technology, the companies said.

"Restarting Duane Arnold marks an important milestone for NextEra Energy ( NEE/PU )," said CEO John Ketchum. "Our partnership with Google not only brings nuclear energy back to Iowa - it also accelerates the development of next-generation nuclear technology.

The Duane Arnold Energy Center -- Iowa's lone nuclear plant -- closed in 2020 after operating for 45 years. While there are now three U.S. restart efforts under way, including a Michigan power plant that is not connected to a technology deal, no mothballed nuclear power plant has actually been restarted.

"This partnership serves as a model for the investments needed across the country to build energy capacity and deliver reliable, clean power, while protecting affordability and creating jobs that will drive the AI-driven economy," said Ruth Porat, president and chief investment officer of Alphabet and Google.

One of the plant's minority owners, Central Iowa Power Cooperative, will purchase the remaining portion of the plant's output on the same terms as Google, NextEra said.

The utility added that it had also signed agreements to acquire the 30% interest in the Duane Arnold plant owned by that cooperative and Corn Belt Power Cooperative, bringing NextEra's ownership to 100%.