Bill Gates-Backed Startup Uses AI to Create Solar Rays Hot Enough to Melt Steel

We may earn a commission from links on this page.
Gif: Heliogen

Like a kid burning holes in their toys using a magnifying glass, solar furnaces essentially do the same thing on a much grander scale. The larger an array of reflectors you can build, the bigger the sun-focusing lens you get. But a new startup is promising a better way to build solar furnaces using AI to reduce their footprint while boosting their power output.

In recent years the price of solar energy has dropped dramatically, and it’s estimated that the cost of building plants like Nevada’s Eagle Shadow Mountain Solar Farm, which officially begins generating power sometime in 2021, is actually cheaper than just operating existing coal or natural gas plants. Harnessing the immense energy of the sun is an obvious alternative to relying on fossil fuels to generate power, but in order to generate the temperatures needed to create molten salt, which is what solar plants like these use to create steam to turn electrical generators, temperatures of around 600 °C are needed, which requires a vast array of reflectors (or heliostats), and a big chunk of land on which to install them. They might be cheaper to build and operate than power plants that run on fossil fuels, but they’re still a hefty investment.


A new startup called Heliogen wants to change that. Functionally, its approach to harvesting the sun’s energy is similar to what existing solar plants use, but with a team that includes scientists and engineers hailing from MIT, Caltech, and other research institutes, the startup plans to harness the power of artificial intelligence to radically improve the efficiency and performance of these facilities. The details of how exactly Heliogen is incorporating AI into its infrastructure is a little vague at the moment—presumably because it’s the startups secret sauce—but “advanced computer vision software” will be used to “hyper-accurately align a large array of mirrors to reflect sunlight to a single target,” according to an official release on BusinessWire.

The more precisely the reflected sunlight from each mirror can be aligned and stacked, the higher the temperatures can be generated, and with its current technology, Heliogen believes that’s well over 1,000 degrees Celsius. But temperatures that intense aren’t only useful for creating molten salt, that’s also the temperature range needed to manufacture commodities like steel and cement, as well as other industrial applications that currently account for roughly 75 percent of the energy demand that’s keeping fossil fuel production running, and that also accounts for a fifth of all harmful emissions.

Heliogen believes that its highly efficient approach to harnessing the free energy the sun throws at us all day long could have wide-reaching applications well beyond just efficient zero-carbon power production. The startup is also confident that eventually, its technology could use the sun to generate temperatures upwards of 1,500 degrees Celsius, at which point it could be used to split carbon dioxide and water molecules to produce clean-burning fuels like hydrogen which promises to be another excellent alternative to gasoline for powering automobiles.

In addition to perfecting its technology and ensuring that it comes up with reliable and cost-effective ways to store surplus energy for those times when the sun doesn’t shine—aka the night—Heliogen also has an uphill battle ahead of it when it comes to convincing companies that have been dependent on fossil fuels for decades to switch over to solar. It doesn’t hurt that the company has managed to raise funding from investors like Bill Gates who’s made a post-Microsoft career out of backing game-changing and humanity improving technologies that are trying to undo the damage caused by the past century of industrial revolution. However, Heliogen’s biggest selling point might be simply that the sun doesn’t charge a dime for all the energy it shares with us.