Think of nuclear power and you may imagine the worst — atomic bombs, reactors melting down and radioactive waste. But while its history is checkered, nuclear energy mostly operates out of sight, generating about 10% of the world's total electricity and 29% of the world's low-carbon power.

Nuclear reactors generate energy day and night, and produce no greenhouse gasses. Still, the growth of nuclear is slowing in comparison to other low-carbon sources like wind and solar.

That's because nuclear power plants are expensive to build, construction often takes longer than expected and public opposition is strong.

For nuclear power to be effective in the future, one key lies in upgrading technology, designing safer and more efficient fission reactors with the support of philanthropists like Bill Gates.

Government labs, private investors, and intergovernmental organizations are also devoting vast resources to what many consider the holy grail of energy — nuclear fusion. Fusion is the process that powers our sun and every other star in the universe. And if we figure out how to harness that power here on earth, it would be a game changer.



