Science and technology are constantly evolving, and over the centuries, man has discovered ways to harness various forms of energy. The very first source of energy to be harnessed was the wind. Ships with sails were the norm until the invention of steam-powered engines. And for the latter half of the 20th century, coal was still the most prevalent source of energy.
It was powerful and consistent, but it was inefficient and highly pollutive. Then by the mid 20th century, the power of the atom was harnessed and the era of nuclear energy began.