Hilariously, a dyson sphere operating at 5% capacity would still generate more power every second than humanity currently generates in 10,000 years.
Luckily with that kind of energy you can do absolutely insane things, like build planet-sized sunshades or push the earth to a more distant orbit. These challenges can be engineered around.
Either way, our ecosystem heats up.
The same is the case with the Dyson swarm. Space goes from being empty to partially re-emitting as a warm object in our direction.
The joule heating from current human power is negligible; conversely, a 4% partial Dyson swarm directly heating the earth (i.e. not just greenhousing Sol) wouldn't be just +3 K change in equilibrium, it would be something like +24,400 K, which would vapourise and gravitationally unbind the planet.
Luminosity of the sun: ~380 yottawatts (3.8 * 10^26 watts)
Sunlight conversion efficiency of a silicon based solar panel: ~20%
A Dyson swarm around the sun built with silicon solar panels: ~76 yottawatts
A Dyson swarm around the sun where 5% of the panels work: ~3.8 yottawatts
The leftovers from a Dyson swarm around the sun where 5% of the panels work and 89% of the output has been used for interplanetary yachts: ~418 zetawatts (4.18 * 10^23 watts)
Primary power production on Earth: ~20 terawatts (2 * 10^13 watts)
10000 years times 20 terawatts is 10000 * 365.25 * 24 * 60 * 60 * 10^12 = 3.16 * 10^24 joules
Since a joule is just a watt-second, it takes 7.6 seconds for that 418 zetawatts of leftover Dyson swarm output to match up to 10,000 years of current human energy consumption.
or
you're saying that if we can harness that much energy amount/density then we can just make matter on spot and we do not have to travel anywhere anymore, because we can make gold bricks or platinum sieves in particle accelerators just for fun? (this is same argument as why alcubierre drive is nonsense, having capability to manipulate such energy density makes us not want to travel anymore)
Making matter from energy would still be inefficient though. c^2 is a really big number.
Also Dyson sphere is old school idea, new more efficient idea is to make small black hole right next to star and harvest energy from that more concentrated flow. So actually black holes colliding (gravitational waves) can be sign of civilization...
Previous post with all those calculations says that you can power 4 149 473 current earths with that amount of energy. I write this with assumption that person is correct (im lazy to calculate that by my self, but it roughly has proper orders of magnitude).
My amazon joke was sarcasm.
No, you will take that elusive flying car because you can afford the energy for it now. And it will be much less efficient than a 747.
Presumably a 5% functional Dyson sphere would be a corrupt boondoggle in the same way as a power plant which is down for maintenance 95% of the year, but the financial calculation would use much larger numerators and denominators than we are used to.