Related by context. Frequent words. (Click for all words.) 59 fossil fuels 57 nonrenewable resources 57 renewable 54 renewable fuels 54 fossil fuel 53 geothermal biomass 52 renewable energy 52 alternative fuels 52 alternative energies 50 renewable feedstocks 49 renewables 49 nonpolluting 48 Cellulosic ethanol 48 liquefied coal 48 biomass fuels 48 carbon emitting 48 synfuels 48 cellulosic feedstocks 48 energy 47 nonrenewable 47 greenhouse gas emitting 47 Renewable Portfolio Standards 47 Renewable fuels 47 Fossil fuels 46 polluting fossil fuels 46 renewable energies 46 biofuels 45 NiMH batteries 45 Integrated Gasification Combined Cycle 45 agricultural residues 45 cleaner burning 44 watt incandescent bulb 44 greenhouse gases 44 baseload generation 44 crop residues 44 burning fossil fuels 44 artificial fertilizers 44 biomass 44 wind turbines solar panels 44 biomass feedstock 44 solar panels wind turbines 44 baseload electricity 43 bio fuels 43 corn ethanol 43 biomass feedstocks 43 desalinization 43 hydrocarbon fuels 43 cleaner fuels 43 Oncolytics clinical 43 ethanol 43 feedstocks 43 fuels 43 sulfur oxide 43 combustion turbines 42 nuclear fission 42 environmentally benign 42 alternatives 42 electric utilities 42 greenhouses gases 42 hydroelectricity 42 regulate carbon dioxide 42 compact fluorescent 42 greenhouse gasses 42 dysprosium 42 compact fluorescent lights 42 watt incandescent 42 Renewable Portfolio Standard 42 liquid fuels 41 compact fluorescent bulbs 41 woody biomass 41 hybrids 41 Lithium Ion batteries 41 coal gasification 41 cold cathode fluorescent 41 switchgrass 41 E# ethanol 41 cellulosic biofuels 41 bulbs CFLs 41 Switchgrass 41 regulate greenhouse gases 41 sulfur coal 41 Carbon dioxide emissions 41 By Julian Pecquet 41 Lithium ion batteries 41 GHGs 41 carbon dioxide emissions 41 carbon sequestration 41 geo thermal 41 Renewable energy 41 harmful pollutants 41 synthetic fuels 41 Renewable Fuels Standard 41 environmentally friendlier 40 compact fluorescent bulb 40 halogens 40 baseload 40 coal fired 40 pellet stoves 40 stover 40 internal combustion engine 40 internal combustion engines