Dreaming the Possible Dream

One has produced a fuel cell that can turn natural gas or natural grass into electricity; the other has a technology that might make coal the cleanest, cheapest energy source by turning its carbon-dioxide emissions into bricks to build your next house.

Let me introduce Vinod Khosla and K.R. Sridhar. Khosla, the co-founder of Sun, set out several years ago to fund energy start-ups. His favorite baby right now is a company called Calera, which was begun with the Stanford Professor Brent Constantz, who was studying how corals use CO2 to produce their calcium carbonate bones.

If you combine CO2 with seawater, or any kind of briny water, you produce CaCO3, calcium carbonate. That is not only the stuff of corals. It is also the same white, pasty goop that appears on your shower head from hard (calcium-rich) water. At its demonstration plant near Santa Cruz, Calif., Calera has developed a process that takes CO2 emissions from a coal- or gas-fired power plant and sprays seawater into it and naturally converts most of the CO2 into calcium carbonate, which is then spray-dried into cement or shaped into little pellets that can be used as concrete aggregates for building walls or highways — instead of letting the CO2 emissions go into the atmosphere and produce climate change.

View Full Article