Fossil fuels are exhaustible natural resources because fossil fuels require millions of years to form from the dead vegetation and animal that get buried deep inside the earth. They require high temperature and pressure for their formation, which cannot be provided in the laboratory.
The ability of the sun to replenish hydro, wind, and biomass make these energy sources renewable. In contrast, the source of nuclear energy is fuel contained entirely on planet Earth. ... This makes nuclear energy inexhaustible.