能源 (néng yuán) literally combines 能 (néng), meaning 'ability' or 'capacity', and 源 (yuán), meaning 'source' or 'origin'. Together, they form the compound noun 'energy source' — referring to any natural or processed material that can be converted into usable energy, such as coal, oil, solar power, wind, or nuclear fuel. It is a formal, widely used term in scientific, environmental, economic, and policy contexts.

This word appears frequently in discussions about sustainability, climate change, national infrastructure, and technological development. Unlike colloquial terms like 电 (diàn, 'electricity') or 油 (yóu, 'oil'), 能源 emphasizes the broader category of resources that supply energy across sectors. It’s commonly modified by adjectives like 可再生 (kě zài shēng, 'renewable') or 化石 (huà shí, 'fossil'), and often appears in phrases like 能源危机 (néng yuán wēi jī, 'energy crisis') or 能源政策 (néng yuán zhèng cè, 'energy policy').