"Amid buzz about algae biofuel and electric cars, some start-ups hope to use "green" technology to reinvent more mundane products like bricks and cement. CalStar Products Inc. plans to open a factory next month to make bricks from fly ash, a byproduct of coal burning. It claims to use roughly 85% less energy than traditional clay brick manufacturing, with an equivalent reduction in carbon-dioxide emissions." (Quoted from article)