Heliogen has created a solar oven — one capable of reaching temperatures that are roughly a quarter of what you'd find on the surface of the sun.
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.
https://www.cnn.com/2019/11/19/business/heliogen-solar-energy-bill-gates/index.html