ಈ ಕೆಳಗಿನವುಗಳಲ್ಲಿ ಯಾವುದು ನವೀಕರಿಸಬಹುದಾದ ಇಂಧನ ಮೂಲವಲ್ಲ?

Solar, wind and ocean-wave energy are renewable: they are naturally replenished. Coal is a fossil fuel formed over millions of years, and it cannot be replaced once used, so it is non-renewable.