Fossil fuels (oil, natural gas, and coal) can be the source of transportation fuels and be used to generate electricity. Other primary sources of energy (nuclear, hydroelectric, and geothermal power, sunshine, and wind) can only be used to generate electricity. Biomass can fuel electricity generation and be the source of gaseous and liquid fuels but only in very small amounts. Hydrogen is not a primary source of energy; it needs to be generated by some process. | Fossil fuels (oil, natural gas, and coal) can be the source of transportation fuels and be used to generate electricity. Other primary sources of energy (nuclear, hydroelectric, and geothermal power, sunshine, and wind) can only be used to generate electricity. Biomass can fuel electricity generation and be the source of gaseous and liquid fuels but only in very small amounts. Hydrogen is not a primary source of energy; it needs to be generated by some process. |