But recently, one of Musk’s companies, xAI, has embraced the mine-and-burn hydrocarbon economy, using dozens of unregulated natural gas turbines to power its data centers with plans to buy $2.8 billion more, effectively cementing the fossil fuel’s role in the company’s AI operations.

It’s a curious turn for a businessman who built his empire on clean energy — and who has no qualms directing his companies to buy from one another. SpaceX spent $131 million on 1,279 Cybertrucks, and xAI has spent $697 million in the last two years on Tesla Megapacks, it’s grid-scale battery storage systems that the company will use to manage peak loads. But so far, xAI hasn’t bought a materially significant number of solar panels from Tesla.

Solar power isn’t missing in the SpaceX filing, it’s just all concentrated on space, which the company touts as the future of data center power. Terrestrial solar garners a few mentions — not as a power source for xAI data centers but instead to show how much better SpaceX thinks space-based solar will be.

It’s no secret that Musk and other Silicon Valley executives have become obsessed with space-based solar power. SpaceX says that space-based solar arrays can generate “more than five-times the energy” of terrestrial ones thanks to 24/7 illumination. As AI data centers have run into opposition here on Earth, CEOs like Musk have started mulling big server racks in space powered by that 24/7 sunshine. Hammer, meet nail.