Elon Musk has promised dramatically lower battery costs, leading to $25,000 Tesla vehicles within three years.

During the company’s Battery Day, Musk talked about the future of battery production. “The battery stuff is clearly revolutionary and essential to Tesla’s goal,” Musk said, “accelerating the [transition] to sustainable energy.”

According to NBC News, Musk said there would need to be significant technological breakthroughs for the cost of batteries to come down lower than they currently are. In the meantime, the company is planning on revamping its entire manufacturing process, streamlining it and eliminating more expensive elements.

The result will be batteries that are not only less expensive, but also pack more energy. Controlling the entire process could give Tesla an even greater advantage over competitors than it currently enjoys.

Either way, Musk is confident $25,000, fully autonomous Teslas will be a reality within three years.