<Li> Solar energy is the use of sunlight . Light can be changed into thermal (heat) energy or directly into electricity via photovoltaic devices . </Li> <Li> Geothermal energy is the use of the earth's internal heat to boil water for heating buildings or generating electricity . </Li> <Li> Biofuel and ethanol are plant - derived gasoline substitutes for powering vehicles . </Li> <Li> Hydrogen can be used as a carrier of energy, produced by various technologies such as cracking of hydrocarbons or water electrolysis . </Li>

How is geothermal power different from the other commercially used forms of renewable energy