Why don't big countries like the US and China build a lot of solar power plants in the Sahara desert to generate electricity for the whole world while giving North African countries a big share?

Indeed: we have a lot of growth room remaining in fields such as solar, geothermal, and in some regions even hydro-electric, to contribute significantly to the grid and world's power needs.

The problem with solar however, remains nighttime and diminished solar-intensity on some days.

On that note, Physics Girl did an interesting video series last year on some new technologies in that field, including this video:

https://www.youtube.com/watch?v=ccO0_hSXMyM


Also if you want to have fun and speculate on the fringe about possible upcoming technologies...

Then once SpaceX's new Starship rocket is flying (providing cheap and large scale access to space, hopefully as promised!), then you can start actually contemplating large scale solar collectors in Earth orbit, with 24 hour nonstop pure-bright constant sunshine unfiltered by a planetary atmosphere...

Which would then be beamed to receiving stations via microwave and/or other EM frequencies.

Not the most efficient transmission of power, but if access to space is a fraction of the cost of what it is today, and satellites can be made much larger for industrial scale power collecting, then the system could likely add a lot of energy to the electrical grid very profitably, and bring down electric costs significantly... perhaps.

People tend to laugh about the microwave-beaming idea...

But people also laughed when SpaceX first proposed Starlink, but Starlink has proven to provide pretty amazing high bandwidth capabilities to any rural spot (even helping the Ukraine military enormously in their battle with Russia).


And of course the ultimate fringe speculation that would solve all power needs is efficient sustainable nuclear fusion.

We know its possible because our sun and all the stars are powered by it. But can we make it compact and do it on Earth?

If so, then the moment it's achieved all power needs are solved for centuries to come, including countless indoor food-growth facilities to solve hunger, and humans would probably quickly settle the entire solar system after that!

/r/NoStupidQuestions Thread