3 ms·
That's a very optimistic view of the future of fusion, IMHO an unreasonably naive view. There are lots of problems with fusion that are unclear if they will eve
by cletus 2y ago
That's a very optimistic view of the future of fusion, IMHO an unreasonably naive view. There are lots of problems with fusion that are unclear if they will ever be solved, specifically:
1. Energy loss from neutron escape. Stars don't have this issue because they are incredibly large (so your neutron will hit something else more likely than not) and gravity;
2. Vessel destruction from lost neutrons (ie neutron embrittlement);
3. Assuming D-T fusion, you're producing helium atoms. Helium is a pesky substance. It's chemically neutral and a helium atom is (AFAIK) the smallest atom, even smaller than a hydrogen atom. That means it is hard to contain and also has a tendency to damage your container;
4. Fusion reactors are, in a way, somewhat primitive. Why? Because ultimately you generate heat and turn a turbine like we do in every coal and natural gas plant. Moving parts are bad.
5. Fuel. Depending on what fuel you need, this is somewhere between a small problem (eg protium or even deuterium) to a hassle (eg tritium) to a major problem (eg He-3).
6. Waste. This depends on fuel somewhat eg do you need to use fissile materials to create Tritium?
Much more detail [1].
We obviously don't know the economics of fusion yet because it doesn't exist, but the economics of nuclear fission are, well, terrible (in both capex and opex terms).
Once you put a solar panel in space, it produces ~7 times the power. There's no loss to cloud cover, getting covered in dust/dirt, atmosphereic loss and the day/night cycle.
For an orbital, you simply cover the exterior with solar panels and you're done for power generation. No moving parts, no catastrophic failure modes (eg meltdowns in nuclear plants), it's scalable and when panels break down you simply remove them and plug in a new one.
I expect other forms of power generation will find a niche use far from the Sun in the same way that submarines have different operating characteristics to a suburb. But I'm skeptical fusion will ever be the preferred method of power generation.
[1]: https://thebulletin.org/2017/04/fusion-reactors-not-what-theyre-cracked-up-to-be/ https://thebulletin.org/2017/04/fusion-reactors-not-what-the...
- TheLoafOfBread 2y agoDyson swarm has some naive approaches too 1. You don't have a way how to transfer power from Dyson swarm without absurdly staggering losses. 2. Dyson swarm satellite would be heated up by incoming heat from Sun on one side and heated up by whatever mean you want to transfer that energy on the other side and unable to cool itself down because it is in vacuum of space. So even that power on the paper is eye popping, actual power would be fraction of a fraction of nameplate power because then you would overheated and destroy it. And now question would be, is such constrained satellite able to make more energy than it was invested into making of this satellite? Combine 1 and 2 together and real output from such structure would be close to zero.
- cletus 2y ago> You don't have a way how to transfer power from Dyson swarm without absurdly staggering losses. Why do you need to transfer power? The point of an orbital is primarily for people to live on. A single orbital could potentially support a million or more people. Are you referring to the issue of providing power to Earth? That's... a separate issue, with different solutions. The idea of power satellites [1] has had a lot of thought. An alternative approach is to build an orbital ring [2] and hang solar power collectors off of it. You could this power directly to the ground with transmission lines. > Dyson swarm satellite would be heated up by incoming heat from Sun on one side An orbital would be heated on the side facing the Sun and radiate away heat away when not facing the Sun in the exact same way that the Moon is scorching hot when facing the Sun and 200 below zero when not. [1]: https://www.youtube.com/watch?v=eBCbdThIJNE https://www.youtube.com/watch?v=eBCbdThIJNE [2]: https://www.youtube.com/watch?v=LMbI6sk-62E https://www.youtube.com/watch?v=LMbI6sk-62E
- TheLoafOfBread 2y agoYou are misunderstanding my question. I am talking about Dyson swarm satellite, not about habitat with solar panels.
- ImPostingOnHN 2y agoHabitat with solar panels = Dyson swarm satellite
- TheLoafOfBread 2y agoSo ISS is now Dyson swarm satellite? Somebody should tell NASA.
- ImPostingOnHN 2y agoYes, thank you for asking a clarifying, good-faith question in order to learn. In fact, the habitat part isn't even required! A dyson swarm is just a bunch of satellites, each harnessing energy from a the same star (what they do with that energy is up to them). 1 satellite is the singular form of satellites. No need to alert NASA, they already know :) The good news is that it seems you might be just now learning that humans have the beginnings of a dyson swarm already in the works. What a great day for you!