?
solar panel
?
wind turbine
?
coal
?
natural gas
?
hydropower
?
oil
?
nuclear power
(adjective) not harmful to the environment
eco - friendly
(adjective) able or likely to cause harm or death, or unpleasant problems
dangerous
(adjective) relating to forms of energy that are produced using the sun, wind, etc., or from crops, rather than those using fuels such as oil or coal
renewable
