Solar is no doubt the coolest.
Hydro and wind are also very neat, going directly from mechanical to electric via generator, without a steam-turbine.
There is also a very cool fusion-category based on dynamic magnetic fields, that basically form a magnetic piston which expands directly due to the release of charged particles via fusion and then captures the energy from that moving electric field by slowing it back down and initiating the next compression.
A fully electric virtual piston engine in some sense, driven my fusion explosions and capturing straight into electricity.
Feels so much more modern than going highly advanced superconducting billion K fusion-reactor to heat to steam to turbine.
Yes! That is super cool tech. If I remember correctly, only about half of the fusion reaction energy was produced as charged particles though. The other half was free neutrons which are notorious for not interacting with the EM field.
I love the idea, it is such a cool direct energy capture method, but it is inherently inefficient.
I’d love to be proved wrong. I did a quick search and couldn’t find the company I’m thinking of, so I’m going off memory.
There are different fusion reactions, one example would be ²H-³He fusion used by Helion.
²H-³He is aneutronic, so doesn’t produce chargeless particles (every clump of stuff is either an electron or contains a proton). It is also an easy to achieve fusion reaction with good energy yield, with the downside that we don’t have ³He. Helion therefore has to split their fusion into two steps, producing ³He via ²H-²H fusion in a breeder-reactor and then fusing it in their energy-reactor. The first step would then emit neutrons and not really produce energy, the neutrons here could be used to further breed fuels.
Not having neutron emissions is quite useful because it allows you to make your fusion generator a lot smaller and safer around people, so it’s certainly something you want to avoid for far more valuable reasons than improving efficiency.
If we get very good with fusion we could also use the much harder to achieve ¹H-¹¹B reaction, which produces some neutrons but at very low energy (0.1% of total energy output), and is effectively aneutronic for safety concerns (neutrons have low penetration power and don’t really activate material, so can’t be used to breed say weapons-grade fission material). ¹H and ¹¹B are common so require no further steps to produce them.
There might still be directly-to-electricity pinch-fusion approaches that use neutronic fusion, I tried looking for any but didn’t find an example. We’ll see what ends up being done in practice, but close to 100% energy utilization is at least possible using pinch-fusion.
On the other hand, the losses in heat-conversion are inevitably huge. The higher the temperature of the heated fluid compared to the environment the higher the efficiency, but given that our environment has like 300 K we can’t really escape losing significant amounts of our energy even if we use liquid metal (like general fusion) and manage to get up to 1000 K. The losses of going through heat are <environment temperature>/<internal temperature> (carnot efficiency), so would still amount to 30% energy loss if we manage to use 1000K liquid metal or supercritical steam to capture the fusion energy and drive a turbine. In practice supercritical steam turbines as used in nuclear plants hover around 50% efficiency at the high end.
The magnetic field in pinch-fusion interacts with the (charged) particles directly, which are emitted at (many many) millions of K. Therefore this theoretical efficiency will be at over 99.99%. In effect in heat-based fusion we loose a lot of that energy by mixing the extremely hot fusion results with the much colder working fluid.
Wait, how can this possibly not involve a turbine? Maybe there’s a semantics thing I’m missing or we disagree on, but what’s turning the kinetic energy into rotational mechanical energy to spin the generator if not a turbine? Or are you saying the turbine is incorporated, as in a turbine generator?
The way I understood it, the system used electromagnets to create a magnetic containment field to drive the fuel together to create the fusion event. That same magnetic containment field would experience a force from the produced charged particles. That force would produce a current in the electromagnets. That current would be stored in capacitors as a voltage which would be used as the energy source for the next magnetic compression cycle. The excess energy stored in the capacitor after the compression would be ‘generated’ energy.
It’s nlt mentioned in the text very clearly, but look at the link.
They were confused about what I said for hydro and wind, which I have now rewritten.
Yeah, not the right words. I intended to say no steam turbine.
Instead of turning energy into heat into turbinable fluid flow in form of steam, they directly use turbinable fluid flow.
The difference is really the lack of steps up to the turbine.
It’s why photovoltaics are so cool. Direct electricity generation without having to spin magnets in circles like neanderthals.
Solar is no doubt the coolest.
Hydro and wind are also very neat, going directly from mechanical to electric via generator, without a steam-turbine.
There is also a very cool fusion-category based on dynamic magnetic fields, that basically form a magnetic piston which expands directly due to the release of charged particles via fusion and then captures the energy from that moving electric field by slowing it back down and initiating the next compression.
A fully electric virtual piston engine in some sense, driven my fusion explosions and capturing straight into electricity.
Feels so much more modern than going highly advanced superconducting billion K fusion-reactor to heat to steam to turbine.
Yes! That is super cool tech. If I remember correctly, only about half of the fusion reaction energy was produced as charged particles though. The other half was free neutrons which are notorious for not interacting with the EM field.
I love the idea, it is such a cool direct energy capture method, but it is inherently inefficient.
I’d love to be proved wrong. I did a quick search and couldn’t find the company I’m thinking of, so I’m going off memory.
Kind of, it’s more complicated.
There are different fusion reactions, one example would be ²H-³He fusion used by Helion.
²H-³He is aneutronic, so doesn’t produce chargeless particles (every clump of stuff is either an electron or contains a proton). It is also an easy to achieve fusion reaction with good energy yield, with the downside that we don’t have ³He. Helion therefore has to split their fusion into two steps, producing ³He via ²H-²H fusion in a breeder-reactor and then fusing it in their energy-reactor. The first step would then emit neutrons and not really produce energy, the neutrons here could be used to further breed fuels.
Not having neutron emissions is quite useful because it allows you to make your fusion generator a lot smaller and safer around people, so it’s certainly something you want to avoid for far more valuable reasons than improving efficiency.
If we get very good with fusion we could also use the much harder to achieve ¹H-¹¹B reaction, which produces some neutrons but at very low energy (0.1% of total energy output), and is effectively aneutronic for safety concerns (neutrons have low penetration power and don’t really activate material, so can’t be used to breed say weapons-grade fission material). ¹H and ¹¹B are common so require no further steps to produce them.
There might still be directly-to-electricity pinch-fusion approaches that use neutronic fusion, I tried looking for any but didn’t find an example. We’ll see what ends up being done in practice, but close to 100% energy utilization is at least possible using pinch-fusion.
On the other hand, the losses in heat-conversion are inevitably huge. The higher the temperature of the heated fluid compared to the environment the higher the efficiency, but given that our environment has like 300 K we can’t really escape losing significant amounts of our energy even if we use liquid metal (like general fusion) and manage to get up to 1000 K. The losses of going through heat are <environment temperature>/<internal temperature> (carnot efficiency), so would still amount to 30% energy loss if we manage to use 1000K liquid metal or supercritical steam to capture the fusion energy and drive a turbine. In practice supercritical steam turbines as used in nuclear plants hover around 50% efficiency at the high end.
The magnetic field in pinch-fusion interacts with the (charged) particles directly, which are emitted at (many many) millions of K. Therefore this theoretical efficiency will be at over 99.99%. In effect in heat-based fusion we loose a lot of that energy by mixing the extremely hot fusion results with the much colder working fluid.
Wait, how can this possibly not involve a turbine? Maybe there’s a semantics thing I’m missing or we disagree on, but what’s turning the kinetic energy into rotational mechanical energy to spin the generator if not a turbine? Or are you saying the turbine is incorporated, as in a turbine generator?
Just so we’re seeing the same picture:
https://www.usgs.gov/special-topics/water-science-school/science/hydroelectric-power-how-it-works#overview
The way I understood it, the system used electromagnets to create a magnetic containment field to drive the fuel together to create the fusion event. That same magnetic containment field would experience a force from the produced charged particles. That force would produce a current in the electromagnets. That current would be stored in capacitors as a voltage which would be used as the energy source for the next magnetic compression cycle. The excess energy stored in the capacitor after the compression would be ‘generated’ energy.
It’s nlt mentioned in the text very clearly, but look at the link.
They were confused about what I said for hydro and wind, which I have now rewritten.
Yeah, not the right words. I intended to say no steam turbine.
Instead of turning energy into heat into turbinable fluid flow in form of steam, they directly use turbinable fluid flow.
The difference is really the lack of steps up to the turbine.
Ahh gotcha, thanks for clarifying! And I agree, very cool stuff.
I swear those magnet spinners are so uncivilized.
Semiconductor gang rise up.
Molten Salt Generators are cool Solar power too.
That they are, but they’re still spinning magnets like our honorable ancestors did.