noun
fossil energy
Refers to energy derived from fossil fuels such as coal, oil, and natural gas. Often used in environmental and policy contexts.
化石エネルギーへの依存を減らす必要がある。
We need to reduce our dependence on fossil energy.
化石燃料 (fossil fuel) refers to the physical fuels themselves, while 化石エネルギー (fossil energy) emphasizes the energy produced from them.
Compound of 化石 (fossil) and エネルギー (energy), a direct calque from English 'fossil energy'.