[jddw]

There are neat ways to make sunlight into fuel, but it's about what form that energy takes. If it is a fuel that needs to be burned - in the case of sugars from photosynthesis - we already do this by burning wood.

I think Cosmos missed a really important lesson which is that the fuels at our disposal are all a function of time and distance. The longer a fuel source has been building, and the less distance it has to travel to be useful to us, the more valuable it may be. The sun is a result of billions of years of the shape-shifting games between mass and energy, all driven by gravity. The fusion energy produced in the sun then has to travel 93 million miles to us to be useful. The food chain harnesses this energy and accumulates it over time, and after hundreds of millions of years much of that energy has been sequestered into fossil fuels. While there is a tremendous amount of power emanating from the sun, it has to go a long way or accumulate for a long time to be useful to us. Nuclear fuel sources on the other hand bring the billions of years of nucleus building that previous generations of stars did for us to our door step. The parent stars of our sun produced heavy actinides like uranium or thorium, as well as the abundant light elements like deuterium, helium, and boron, and then scattering them across the cosmos along with leftover hydrogen in brilliant novae and supernovae. In our case, many of these elements were in the stardust that formed earth, and are here beneath our feet and above our heads.

Solar, wind, and nuclear will dominate the 22nd century, but we need both, and they do and can play well together. They just need to be treated and respected equally.

[Retric]

Heavy elements that allow for Fission are products of supernova which are really more a question of minutes than years. With the vast majority being created in under 2 minutes after the reaction starts.

PS: https://what-if.xkcd.com/73/

Which of the following would be brighter, in terms of the amount of energy delivered to your retina: A supernova, seen from as far away as the Sun is from the Earth, or The detonation of a hydrogen bomb pressed against your eyeball?

A: Applying the physicist rule of thumb suggests that the supernova is brighter. And indeed, it is ... by nine orders of magnitude.

[lutorm]

Why does it matter how far away the Sun is? It's the amount of energy available to us here that matters. And it doesn't have to accumulate at all, the instantaneous energy flux is plenty high for our needs.

[DennisP]

Except for the darn planet getting in the way half the time.