Won’t be any economy left if the planet is made uninhabitable. It’s like the most sacred thing is profit, not anything about the people that create it. Very odd train of thought.
Well, it does and that assumption cost expensive time.
The comment was that nuclear was replaced by renewables for power generation.
Neither nuclear or renewables replace coking coal. There is a hydrogen steel cycle that can though but not in industrial quantity yet.
Perpetual motion _engines_ violate law of energy conservation, because perpetual source of energy can create infinite amount of energy, thus they are impossible, like perpetual source of water, or perpetual source of anything.
Note that DT fusion is a thermal power technology. It makes heat that drives a thermal cycle. It turns out that all externally heated thermal cycles have become uncompetitive for power generation, just because of the cost of the non-reactor/non-boiler components. This includes fission, solar thermal, geothermal, and coal. So even if a DT fusion reactor is delivered FOR FREE from the fusion reactor fairy, it will not be competitive. Expecting capital equipment to have zero or negative cost is a good economic analogue for a perpetual motion machine.
So, what's the alternative? It's going to have to be something using advanced fuels and direct conversion. That means all the efforts with tokamaks are ruled out (they cannot work with advanced fuels and have no place for adding putative direct conversion.) And what advanced fuels are we talking about? D-3He would require space mining of the outer planets (the much-discussed lunar resource, even if it could be mined at 10 ppb in the regolith, would only last centuries before being exhausted.) And H-11B is extremely difficult, because the energy out is only about 10x the kinetic energy of the particles, so very little loss can be tolerated. In particular, systems in thermal equilibrium will have a very difficult time reaching breakeven, due to large photon losses.
Another showstopper is the absolutely terrible power density of fusion reactors. This follows from general principles (geometry and the square cube law). If you look at all existing fusion reactor proposals, ask what their thermal power/volume is. You will discover they are terrible compared to fission reactors (ITER 400x worse, ARC 40x worse). So ask yourself: why is this going to be cheaper than fission reactors? The fusion reactors are both larger, more complex, and made of much more sophisticated materials. And fission has already lost the economic race.
The larger more complex reactors are really bad news for reliability and maintainability. Estimates for the fraction of time a fusion reactor will be up, given current estimates of MTBF and MTTR, are just a few percent. This is inadequate even for an experimental reactor. There is not much budget space for operating costs from a fusion reactor before just that becomes prohibitive.
From a hard nosed engineering point of view, fusion is just ridiculous. It piles complexity upon complexity in a large machine that will be too radioactive for hands on maintenance. How could you think this would ever make sense?
I think you meant to say "I hope we develop fusion so we can leave the solar system".
Oof. One need only to peruse your comment history to see where this sentiment is coming from, but even that is no excuse for that obtuse argument.
"Perpetual motion," on the one hand, is quackery outlawed by straightforward thermodynamics, breaking the rules of which allows assertions like "chair seats and door handles should be spontaneously heating up to incandescence essentially at random." Fusion, on the other hand, is a technical problem.
Fusion researchers at MIT, ITER, and other institutions at the top tiers of academia across the globe are not a cabal of greedy grant-dependent charlatans bamboozling their way through careers in bad faith, deliberately ignoring the lone rational voice of Lidsky and his Johnny-Come-Lately-The-Baptist on HN, u/pfdietz. It's perfectly rational (Sane, even!) to cast aside internet naysayers (no matter how zealous) in favor of deferring to, you know, actual experts.
In general, you don't want to ask a person in field X if X needs funding. You might ask them what's the best way of spending money in X, but even then you better phrase the question carefully to avoid conflict of interest.
But maybe all we will ever need are solar panels, after all the sun is providing way enough energy as is... for now.
[1] https://en.wikipedia.org/wiki/Aneutronic_fusion
working in another '50' years? :-)
Then his PhD student Todd Rider shot down the very low neutron fuel cycles. D-3He remains possible, but that still produces neutrons, albeit fewer than DT (and requires mining bodies in space to get 3He).
The neutron bombardment makes the waste less radioactive.
With recycling and purification steps, we can direct the equipment to generate more of the isotopes we value and less of the isotopes that are undesirable.
There has been repeated talk of putting transuranic waste into fusion reactor blankets for destruction or breeding (so called fission-fusion hybrids) but these inherit all the negatives of fission and fusion reactors (the worst of both worlds) without any big advantages to compensate. And this would just be materially passively loaded in blankets, not essential structural elements (that, for one thing, cannot spring any significant leaks without ruining the plasma by allowing coolant into the vacuum vessel.)
Just saw a talk [0] where they talk about using lasers to create fusion. The current puck used to kick start the process costs $1M, (paraphrased) "it needs to cost 20 cents before Fusion is viable. But hey, we're in the research phase!"
https://www.geekwire.com/2019/inside-terrapower-nuclear-lab/
Safe from meltdown, uses existing nuclear waste as fuel, might be tested in China.
This is false. Germany replaced their nuclear capacity with, for the most part, wind and solar, plus natural gas.
Coal consumption in Germany is down by 50% since they began their nuclear drawdown.
There might be 50% accounting drop in some reports thanks to all the biomas co-firing making coal plants ECO on paper, at the cost of freshly chopped European forests.
Obviously, because you're looking at installed peak capacity, not actual power generation. Here you can see that coal is indeed being used less and less: https://energy-charts.de/energy_de.htm?source=all-sources&pe...
As we have seen, big changes of any kind that displace or destroy the livelihoods of vast numbers of people always lead to some form of populist or revolutionary revolt. Whether it takes a "left" (populist-socialist/communist) or "right" (national socialist) form depends mostly on which side is able to field the most compelling demagogue that can best harness the anger of the masses.
Abandoning fossil fuels must be done in a way that cushions the public and the economy somewhat or we will have a full scale populist revolt with slogans like "roll coal!"
Germany's choice isn't to start producing electric cars or to keep producing the same number of ICE cars they always did. It's to start producing electric cars or lose most of the market to new competitors.
And that means there are going to be fewer jobs making cars, because it's less labor to make an electric car. But you don't bail out the buggy whip makers, they just start making drive belts, or they go away.
There are effectively unlimited jobs at low enough pay, so as long as the pay meets the cost of living it's fine, so anything that lowers the cost of living is good.
That balance doesn't operate at the individual level. It mostly benefits the people who buy cars and mostly hurts the people who used to make cars. But on net it helps more than it hurts -- it's better to make transportation less expensive than have some more jobs that cause transportation to be more expensive.
The biggest problem with this is that it works best when everything gets cheaper at once. Otherwise that individual-level asymmetry starts to become trouble. And what we have right now is a regulatory environment that makes it hard to get cost reductions in certain industries (housing from zoning rules, education from government subsidies, healthcare from a hundred separate causes), so those keep growing as a percentage of income. And that's going to be a problem if we don't do something about it.