We have burned for energy for a long time, starting with the local wood and plants around us. Manure can be burned and so can lots of our garbage. This is renewable but it does add carbon dioxide. It is possible to grow biomass as a crop, making energy generation into an agricultural industry. This is a growing thing in many places on earth. There should be an analysis about whether the agricultural industrialization of biomass is efficient and sustainable, since it does require substantial energy input. Ethanol already is part of our liquid auto fuel.
Read Chapters 40, 41 Michigan Geography and Geology
