NextEra Energy and Google announced on October 27 that they will restart the Duane Arnold Energy Center, the 615 MW nuclear plant near Cedar Rapids that closed in 2020 after 45 years of operation. Google signed a 25-year agreement to buy the plant's output once it returns, and NextEra expects Duane Arnold to be delivering electricity onto the grid by the first quarter of 2029, pending regulatory approvals.
The deal makes Iowa's only nuclear plant the latest retired reactor pulled back into service by data center demand. Reuters noted that there are now three U.S. restart efforts underway.
The terms
Under the agreement, Google will buy power from the plant as a 24/7 carbon-free source for its cloud and AI infrastructure in Iowa, NextEra said. Central Iowa Power Cooperative, one of the plant's minority owners, will buy the remaining output on the same terms as Google.
NextEra has signed definitive agreements to acquire the combined 30% interest held by Central Iowa Power Cooperative and Corn Belt Power Cooperative, which will bring its ownership to 100%. The company said the restart is expected to create about 400 direct full-time jobs and deliver more than $9 billion in economic benefits to Iowa.
Google's own description of its role is unusually direct. "Through this agreement, we're enabling the investment to restart the plant and covering costs for the production of energy from Duane Arnold," the company wrote. Google said the plant will provide more than 600 MW of "always-on" nuclear energy to the regional grid.
That is a different structure from a conventional power purchase agreement in which a buyer simply pays for megawatt-hours from an existing project. Here the buyer's commitment is what makes the capital spending possible in the first place.
Why restarts come first
Google framed the choice plainly. "Restarting a once fully operational plant is the fastest path to unlock large-scale nuclear power to meet AI growth in the near-term," it said.
The comparison with new construction explains the logic. A restart uses an existing reactor, an existing site and an existing grid connection. A new reactor has to be designed, licensed and built, and the advanced designs Google has backed elsewhere are not expected to reach commercial scale until the 2030s. A 2029 date for 615 MW of firm power is early by nuclear standards.
The tradeoff is that the supply of candidate plants is small. Only a handful of U.S. reactors have closed recently enough, and with their equipment intact enough, to be considered for restart. With Duane Arnold, three of them are now being pursued.
NextEra chief executive John Ketchum called the restart "an important milestone for NextEra Energy," adding, "Our partnership with Google not only brings nuclear energy back to Iowa, it also accelerates the development of next-generation nuclear technology."
A second agreement on new reactors
The restart was one of two agreements announced together. NextEra and Google also agreed to explore the deployment of nuclear generation across the United States. The companies did not attach a capacity figure or a timeline to that second agreement, so it is best read as an option rather than a commitment.
The pairing shows how hyperscalers are building nuclear portfolios. Restarts and contracts with operating plants provide firm power in the late 2020s, while development agreements for new reactors aim at the following decade. Google's existing deal with Kairos Power and the Tennessee Valley Authority sits in that second category.
Google placed the restart alongside other tools it is using to secure power, from advancing new clean generation to making its own demand more flexible and deploying next-generation transmission technology. Each of those approaches addresses a different bottleneck. New generation adds supply, flexible demand lets data centers ease off during grid peaks, and advanced transmission equipment squeezes more capacity out of existing lines. A restart is the one option that delivers a large block of firm, carbon-free output on a known site, which explains why Google agreed to cover the costs of bringing it back.
What it means for the Midwest grid
Duane Arnold sits in the territory of the Midcontinent Independent System Operator. Returning 615 MW of output that runs around the clock adds firm supply to the regional grid without the multi-year wait that a new plant would face for an interconnection study, since the site already has its connection.
Because Google's purchase is tied to its Iowa operations, the plant's output will serve load in the same state rather than being matched on paper against consumption elsewhere. That fits the 24/7 carbon-free goal Google has set, which seeks to match consumption with clean supply hour by hour on the same grid.
The cooperative share matters too. By buying the rest of the output on the same terms, Central Iowa Power Cooperative gains access to nuclear power for its member systems on contract terms that a large technology buyer helped underwrite.
What could slow it
The schedule depends on federal regulators. NextEra's 2029 date is explicitly pending approvals to restart the plant, and the Nuclear Regulatory Commission is still working through the first attempts to return shut reactors to service, including the Palisades plant in Michigan. Those early cases will set the template for how long reviews take and what equipment has to be replaced.
Supply chains are the other constraint. Restarts need large components, specialized labor and fuel, all of which are also in demand for license extensions and uprates across the existing fleet.
What to watch
The next milestones are NextEra's regulatory filings with the NRC and the closing of its purchase of the cooperatives' 30% stake. Investors will also watch for any sign that the second agreement, on new nuclear deployment, turns into specific sites or reactor designs.
For other hyperscalers the deal sets a benchmark. A buyer willing to cover restart costs and sign a 25-year contract can bring a retired plant back within about four years. The number of plants that can be revived this way is limited, which is why the same companies are also paying for reactors that do not yet exist.