Have you ever dreamed of a world where you could take the scraps from last night's dinner and toss them into your car's fuel tank and make gas? Well, we're not quite in "Back to the Future" yet, but in this energy science fair project, you'll discover that food scraps, dead plants, sawdust, and other decaying organic matter, called biomass are a rich source of energy. You can get energy out of biomass by burning it, turning it into a liquid, or by turning it into a gas called biogas. You've probably burned biomass (like dead wood) before if you've ever built a campfire, and you've seen biogas being produced if you've ever watched cows happily munching on green grass. The cows eat a type of biomass (grass or hay) and turn it into the biogas, methane, in their digestive tracts. In this energy science fair project, you'll compare the amounts of biogas produced by different types of biomass.