A secretive startup backed by Bill Gates has achieved a solar breakthrough aimed at saving the planet. //

Heliogen, a clean energy company that emerged from stealth mode on Tuesday, said it has discovered a way to use artificial intelligence and a field of mirrors to reflect so much sunlight that it generates extreme heat above 1,000 degrees Celsius. //

The breakthrough means that, for the first time, concentrated solar energy can be used to create the extreme heat required to make cement, steel, glass and other industrial processes. In other words, carbon-free sunlight can replace fossil fuels in a heavy carbon-emitting corner of the economy that has been untouched by the clean energy revolution. //

Heliogen uses computer vision software, automatic edge detection and other sophisticated technology to train a field of mirrors to reflect solar beams to one single spot.

"If you take a thousand mirrors and have them align exactly to a single point, you can achieve extremely, extremely high temperatures," Gross said, who added that Heliogen made its breakthrough on the first day it turned its plant on.

Heliogen said it is generating so much heat that its technology could eventually be used to create clean hydrogen at scale. That carbon-free hydrogen could then be turned into a fuel for trucks and airplanes.