Concentrated Solar Power (CSP) startup Heliogen has been selected by Rio Tinto to develop a project at the latter’s borates mining operation in Boron, California to power the mine’s industrial processes. Most CSP plants reach at most 565°C, limited by the use of molten salt as a heat transfer fluid, while Vast Solar in Australia reaches 800°C using liquid sodium. Heliogen’s technology reaches 1000°C, perhaps even 1,500°C, which would be hot enough to produce oxygen and hydrogen via thermochemistry. Heliogen has dubbed this “Heliofuel”. There is some mystery around Heliogen’s heat transfer fluid (HTF) – its past installations have been modular and small-scale, not like the old clunky molten salt CSP plants. Rio Tinto has claimed the installation will have…