Beaming Down Power From Space
As I said I would yesterday; here is my post about power satellites as seen on the Isaac Arthur YouTube channel. Probably notable as one of the futuristic ideas Elon Musk doesn't believe is feasible.
To be fair the video makes the same point as Elon Musk does: it currently has a low conversion rate. Reducing the number of steps in the conversion process would obviously increase the efficiency. Just beaming it somewhere else in space rather than down to Earth's surface improves the process. Instead of a fraction of the energy heating the atmosphere the beam of energy could be directed toward a solar sail or maybe avert an asteroid.
Imagine a satellite way up above in orbit. It is beaming down microwave energy a little less than 100 watts per square meter. Instead of solar panels a mesh of wire, specifically rectennas, cover the roof of buildings. That mesh is converting the microwave energy into electricity.
The video states that if you divide the amount of electrical power consumed globally by the Earth's population the average person uses 2400 Watts a day. No doubt I go through more than that daily without thinking about it. Just doing my part to make up for the Amish slackers I guess.
The video also points out that solar panels aren't the only way to generate power on a satellite. Sunlight can be focused to boil a liquid to turn a turbine for power.Getting rid of the excess waste heat is an engineering problem but the advantage is heat engines have been around longer than solar panels so the principles are already well understood and developed.
As the cost of launching mass into space decreases and technology increases chances are most power will be geberated in space. Whether or not it gets beamed down to Earth's surface or sent toward a colony off-planet is more uncetain. The video ends talking about orbital rings and space towers as the platforms for these power plants of the future but active support structures are discussed more in other videos so I'll leave it there until I get to them.