The idea is as spectacular as it is obvious: a lawnmower fueled by grass. A prototype has emerged from a startup originating at George Mason University in Fairfax, Virginia. EcoMow which essentially means “ecological mowing” dries freshly mown grass in its interior using a combustion engine and compresses it to biomass pellets. The mower uses up some of the pellets for its own propulsion. The remaining pellets can be used, for example, as fuel for furnaces.