Fusion has been the power source of the future for decades, and while progress has been made, actual fusion power plants seem as far off as ever. And let’s not even get into spacecraft fusion propulsion. So many concepts call for fusion rockets like it’s no thing. We seem even further away from fusion rockets than fusion power plants. My question is: will fusion energy and fusion rockets ever become a reality?
Ever is a very long time. The next 200 years? No way. The next 200 centuries? Maybe. If we haven’t found & perfected something far better than stupid puny fusion by then.
Fusion energy is already a practical power source. It’s called ‘the sun’.
It’s possible that’s not what the OP was referring to.
But we all know the sun is a mass of incandescent gas, a gigantic nuclear furnace. Right?
Where hydrogen is built into helium / At a temperature of millions of degrees?
Though lately I’ve heard that the Sun is a miasma of incandescent plasma
I gave up all of my incandescents for LEDs.
The question is whether nuclear fusion can be scaled down and controlled. We know it can be scaled down from the scale of the sun and stars, because hydrogen bombs. We know it can be controlled because of experimental fusion reactors. What we don’t know is whether fusion reactors can be economically practical in the sense of providing more energy than they consume.
Fusion rockets just might actually be easier than fusion power plants. In fact, we already know one way to make a fusion rocket, the Orion method: The engineering of it would be a beast, but the principles are simple enough.
In this podcast episode the founder of a fusion company talks about the future of fusion energy. It’s been a while since I heard it, but I believe they’ve developed more efficient methods of isolating deuterium and tritium than the traditional methods. They hope to use these advancements to make money and fund their fusion research. I do recall that instead of “20 years” he was saying “10 years”.
This podcast generally has an optimistic tone. The host will ask hard questions and push against vague answers, but the whole point of the show is to hear about how people plan to overcome the difficult problems.
Nuclear fusion is the power source of the future - and always will be.
Why do you think that? It’s not like there’s a hard barrier to it like there is for FTL travel. Scientific experts consider it something that continued advancement in engineering/technology will eventually overcome, though they admit it may a while. But never? Please elaborate on your assertion.
I’ll be the voice of positivity.
I know during our lives, the press has often made it sound like viable fusion plants were only 20-30 years away, but here is the thing. It looks like viable fusion plants will be up and running in the 2040s or 2050s.
The technology is getting there and the demand* for electric keeps rising. To go fossil fuel-free will take more than hydro, solar & wind. Fission has a lot of issues that fusion does not. BTW: this summer is showing a lot of problems with hydro-electric. Many are failing due to record low water amounts.
*On the Demand: AI server farms are driving the increase in demand. In the US it is over 50% of the increase. Climate issues are driving a big surge in demand for air conditioning in Europe. In general, world-wide, electric vehicles and heat-pumps have increased demand,
Fusion has 3 challenges left:
- Self-sufficient breeding of tritium from Deuterium,
- Material Degradation: Vessel walls must withstand severe, continuous neutron bombardment. This is my biggest worry for continued delay.
- Sustained positive Net Energy: getting significantly more energy out of the process than we put in. This was the biggest obstacle, but projects having been improving in this area and several different tests have now shown net energy output. We’re probably closest on this issue now.
Is that true? My understanding was that if you only look at the energy actually applied to the materials, it was net energy output, but if you look at the energy drawn to apply that energy, it’s still not net positive.
Ha, exactly! A given technology can only improve so much. Leaps in advancement have come from replacing those technologies with new, different, and better ones.
I think you’re correct about that. But it seems like the consensus is that they will accomplish this by 2033. Possibly as soon as 2027. Multiple plants are being built with this expectation.
But if the vessel is not able to be sustained for a reasonable cost, just making the experiment work won’t make fusion a viable energy source.
I’m pretty sure you’re right. ‘net positive’ looks nice in a press release, but I suspect they are still quite a few orders of magnitude away from net positive from the whole apparatus.
Also they are all using tritium, which doesn’t exist in nature because of its short half-life. Where are they proposing to source this from? Tritium fusion also produces a ton of neutrons, so the promise of ‘clean’ energy is a bit disingenuous.
I don’t know enough about physics to know if there are hard limits on fusion plants as a way to produce energy or not. But if the laws of physics allow it, eventually humanity will learn how to do it. Its just a matter of when.
What I also wonder is if microscopic black holes will ever be a source of electricity. Will we ever be able to create microscopic black holes and feed matter into them, then use the energy that is produced.
Either way, breeder reactor technology already exists for fission. So I don’t know if fusion electricity will ever be economically viable, even if it is physically possible.
Also advances in fracking have also led to advances in geothermal energy. Some of the technologies needed for fracking like drilling miles into the earth can also be applied to generating geothermal energy. So geothermal energy may experience a renaissance in the decades ahead.
The point is that breeder fission reactors, geothermal, etc may provide baseload energy which may reduce the demand for fusion reactors making them less economically sustainable. So even if we learn how to build fusion reactors in the 2060s, will we even need them since they probably won’t be the cheapest way to generate base load electricity. I’m not sure.
There is a stat that says the net energy output of the sun’s core, calculated per cubic foot of volume, is about the same as an active compost heap. The sun, of course, has a few more cubic feet of volume than a typical compost heap.
It would seem more sensible, to me, to develop molten salt fission breeder reactors, which are a lot safer than typical high-pressure water reactors, and more importantly, we know they can be made, and we know how to make them. Contained fusion just looks like an endless avenue of almost there, when we have alternatives that are within reach.
Your first paragraph adds nothing to the debate. Pithy little factoids don’t argue against the use of working fusion plants.
I believe both the US, China and Europe are already looking into or building molten salt fission breeder test reactors but they do have their own concerns.
Weapons grade uranium-233 being one of the byproducts. Also, like fusion, the structure of these plants will degrade quickly. The embrittlement is a real worry. Remote controlled robots are probably up to the task of maintenance now, but the material of these plants will be very radioactive and humans won’t be able to work on them directly.
We’ve been playing with this idea since the 1960s I believe. There are reasons no one has them up and running yet.
ETA: I just read, one of the byproducts is Tritium, so maybe helpful to future Fusion plants.