The large language models powering AI are trained in data centers with unimaginable appetites for energy, and for big tech companies, the stakes for getting enough power for those plants are high. It's why Microsoft is now throwing its weight behind nuclear power. The tech giant signed a major deal Friday with nuclear power plant operator Constellation Energy to buy electricity for its data centers at the utility's Three Mile Island Unit 1 nuclear power plant.

It was located right next to TMI Unit 2, which melted down in 1979. Block 1 was shut down in 2019 because of the drop in demand for nuclear energy with regard to the context of competition against cheap alternatives like natural gas, solar energy, and wind.

Constellation  is said to announce an investment of $ 1.6 billion in the first unit 1 renovation pending the regulatory bodies by 2028. Financial terms of the deals have not been disclosed. Constellation officials have agreed to a reactor power receipt for the upcoming 20 years. The reactor has assured a power output of 835 megawatts following restoration.

It will also be known as Crane Clean Energy Center, in honor of the late former CEO of Constellation Chris Crane, who passed away in April. It is expected to generate 3,400 direct and indirect jobs and contribute $16 billion to Pennsylvania's GDP while raking in over $3 billion in state and federal taxes, according to an economic report commissioned by the Pennsylvania Building & Construction Trades Council.

Data centers and other industries central to our nation's global economic and technology leadership need abundant, carbon-free and always-on energy.  Altman himself has been quite vocal about his interest in nuclear power, and Amazon bought up a nuclear data center in Pennsylvania for $650 million back in March. All three companies-Microsoft, Amazon, and Alphabet-have separately announced goals to power their data centers with 100% green energy. Microsoft aspires to reach this by 2030, but this past May, the company copped to the reality that its AI work is standing in the way of that ambition.

This June, it was reported by Bloomberg that data centers of the future belonging to the tech giant promise to suck in as many as 508 terawatt-hours of electricity per year if those were to operate unceasingly. That's more than all the electricity produced in Australia in one year.

In fact, the demand for clean electricity to power not just data centres but electric vehicles, factories and more has sparked something of a renaissance around nuclear power. Investors are increasingly bullish on nuclear fusion startups-which have raised $7.1 billion to date-since it represents a cleaner, more powerful future for nuclear power. It uses hydrogen as fuel whereas nuclear power plants and their fission process rely on hard-to-come-by elements like uranium and plutonium.