NextEra has agreed to reopen a nuclear power station in Iowa that will primarily provide power to Google as the tech giant races to secure clean energy to drive its artificial intelligence data centres.

The largest renewable energy company in the US will lead the redevelopment of Duane Arnold Energy Center after Google signed a 25-year agreement to buy electricity from the power station. After being shut down for five years, it is expected to cost more than $1.6bn to restart.

Duane Arnold, a 615-megawatt plant, is expected to start delivering power by 2029, according to NextEra. It is the third US nuclear plant to begin the process of restarting operations.

"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.

Google said it also agreed to explore opportunities with NextEra to deploy new nuclear generation capacity in the US amid soaring demand for electricity linked to the rollout of AI.

Nuclear power has been enjoying a renaissance in recent years following a move away from the fuel source due to increased competition from low-cost shale gas and the 2011 Fukushima accident in Japan.

The ability of nuclear energy to provide round-the-clock carbon-free power has pushed it back into the spotlight as the world aims to slash emissions while feeding a rapidly growing need for electricity.

Google's power supply deal with NextEra follows a similar agreement between Microsoft and Constellation Energy last year, which is expected to enable the Three Mile Island nuclear plant in Pennsylvania to reopen in 2028.

The Palisades nuclear power plant in Michigan is scheduled to be the first fully decommissioned US nuclear power plant to reopen later this year.

It is much more cost effective and faster to reopen a mothballed power plant than build a new facility from scratch, according to nuclear experts.

Critics of nuclear energy have warned that any effort to reopen retired power plants must not be rushed and should adhere to strict regulatory standards.

Edwin Lyman, a physicist at the Union of Concerned Scientists, said restarting Duane Arnold should proceed with extreme caution, particularly because of damage it sustained in a type of storm known as a derecho.

"The ageing reactor, which is the same design as the reactors that melted down at Fukushima, Japan in 2011, was shut down after it was struck by a derecho in August 2020 and suffered serious damage, including the destruction of its cooling towers," Lyman said.

"Until NextEra presents a realistic estimate of the cost to rebuild the plant and restore it to a safe condition is developed, no one will really know if this reactor will be able to generate affordable electricity."

However, industry regulation is expected to grow and evolve as there are additional efforts to reopen shuttered reactors, according to Adam Stein, director of the nuclear energy innovation programme at The Breakthrough Institute.

"Thanks to the Palisades restart, there is a regulatory process and a clear understanding of what inspections need to be completed."

NextEra and Google agree deal to reopen US nuclear plant