Piketon, Ohio - Japan's SoftBank Group said Saturday it plans to build a huge new gas-fired power plant in Ohio to provide energy for artificial intelligence data centers.

Tech investor SoftBank is a major backer of ChatGPT maker OpenAI, and its flamboyant CEO Masayoshi Son is a long-time ally of President Donald Trump.

The natural-gas plant is part of a broader $550 billion Japanese investment in the US that Tokyo agreed to in exchange for reduced trade tariffs.

Construction of the $33.3 billion power plant with a "large-scale" power generation capacity of 9.2 gigawatts will take place at the US Department of Energy's Portsmouth site, SoftBank said.

"This is a size bigger than any power plant, I think, in the world," Son said at a ceremony in Ohio to announce the project, on Friday local time.

"At least in the United States, for sure, this is the biggest power generation in one location," he added.

The goal is to develop "the smartest intelligence in the world," Son said.

The 9.2 GW gas-fired plant is part of an overall plan for the site to power 10 GW of data center capacity, the US Department of Energy said in a statement.

"Once a cornerstone of America's national security during the Cold War – enriching uranium for our nation's defense – the Portsmouth site is now being transformed to help the United States win the AI race," it said.

SoftBank on Saturday announced a consortium with major American and Japanese firms to help build the plant and develop AI infrastructure in Ohio.

Data centers that can train and run chatbots, image generators, and other AI tools are being built on a dramatic scale worldwide as an investment boom into the fast-evolving technology shows no sign of slowing.

A study last month found that industrial investment surged by nearly a third in 2025 thanks to investment in AI and data centers in the US.