What source of energy is this?
natural gas
What source of energy is this?
nuclear power
What source of energy is this?
coal
What source of energy is this?
oil
What source of energy is this?
geothermal power
What source of energy is this?
Hydropower
What source of energy is this?
Wind power
What source of energy is this?
solar power
What source of energy is this?
biomass