The process is ludicrously energy intensive, with experts estimating that the industry could soon suck up as much electricity as an entire country.

So it shouldn’t come as a surprise that OpenAI CEO Sam Altman is looking for cheaper alternatives. During a Bloomberg event at the annual World Economic Forum in Davos, Switzerland, the billionaire suggested that the AI models of tomorrow may require even more power — to the degree that they’ll need a whole new power source.

“There’s no way to get there without a breakthrough,” Altman told audiences, as quoted by Reuters. “It motivates us to go invest more in fusion,” adding that we need better ways to store energy from solar power.