Primary energy sources can be classified in to two groups: nonrenewable and renewable. Secondary sources are derived from primary sources.
Energy from the ground that has limited supplies, in the form of gas, liquid or solid, are called nonrenewable resources.
Natural Gas
More about Natural GasPetroleum
More about PetroleumCoal
More about CoalUranium
More about UraniumEnergy that comes from a source that’s constantly renewed, such as the sun and wind, it can be replenished naturally in a short period of time.
Hydropower
More about HydropowerSolar
More about SolarWind
More about WindGeothermal
More about GeothermalBiomass
More about BiomassEnergy that is converted from primary sources are secondary sources of energy. Secondary sources of energy are used to store, move and deliver energy in an easily usable form. Examples include electricity and hydrogen.
Electricity
More about ElectricityHydrogen
More about Hydrogen