Mixing In Some Carbon

“With this technology, coal can be cleaner than solar and wind, because they can only be carbon-neutral,” said Vinod Khosla, the Silicon Valley billionaire. His venture capitalfirm, Khosla Ventures, has invested about $50 million in Calera. On Monday, Calera is set to announce thatPeabody Energy, the world’s biggest coal company, has invested $15 million.