Major nuclear fusion milestone reached as ‘ignition’ triggered in a lab • Hacker News Board

Re: Major nuclear fusion milestone reached as ‘ignition’ triggered in a lab

#331

Post by 08-15 » Tue, Oct 12, 2021, 8:58 PM UTC

rfrey wrote: post #118

08-15 wrote: post #76

Earlier quoted context omitted.

How come? Conventional electricity plants also convert heat to electricity. That doesn't sound fundamentally different from your business. Was your input temperature too low? That would explain it. At low temperature differential, you have lower efficiency and need much bigger machinery for the same output. That said, fusion has a chance to be competitive, because the temperature will be higher. (Obviously, the therm…

Our heat sources were typically in the 500-600C range, with plant exhaust flows containing about 80-150MW of energy. Current tech can convert that with about 20% efficiency. Not at all like conventional electricity plants, the heat is already being created in industrial processes and is a waste product. We're familiar with delta-T and thermodynamics. Current off the shelf technology can easily hit half of the Carnot…

Wait, what? Coal plants operate with an upper temperature of under 600C, and they approach 40% efficiency. Why do you say it's only 20%?

Either way, it sounds as if a coal plant without the furnace wouldn't be able to compete with "conventional electricity". What is "conventional electricity" then? Open cycle gas turbines? Are they that much cheaper, even including fuel cost?

Re: Major nuclear fusion milestone reached as ‘ignition’ triggered in a lab

#332

Post by thow-58d4e8b » Tue, Oct 12, 2021, 9:00 PM UTC

onion2k wrote: post #283

rfrey wrote: post #61

Meta-question about fusion energy -something I don't understand about the movement. I spent a few years as CTO of a company providing heat-to-electricity plants. We financed and built them off high-heat plants like natural gas turbines. The "fuel" was heat going up the stack - so it was essentially free. We still couldn't compete with conventional electricity plants, even with a $30/tonne price on carbon in Canada. G…

Simple solution - nationalize energy production.

Proposing nationalization is akin to blasphemy nowadays - way outside of Overton window. But I haven't really heard any good arguments or benefits of electricity production and distribution being private.

On the other hand, there are a lot of good arguments in favor of state ownership - matter of national security, need for redundancy instead of efficiency, it's a commodity and a basic necessity, low margins, large scale leads to financing issues for corporations, chicken-egg problems that state is better at dealing with, the domain is primarily about engineering challenges with branding and management having very limited impact, simple supply chains, cost-cutting may lead to disastrous consequences, etc...

Re: Major nuclear fusion milestone reached as ‘ignition’ triggered in a lab

#333

Post by Andrew_nenakhov » Tue, Oct 12, 2021, 9:02 PM UTC

Qwertious wrote: post #306

Andrew_nenakhov wrote: post #192

Earlier quoted context omitted.

Had we gone down this road, we'd have a thick layer of manure covering everything. Living creatures are a source of CO2 too, and a big one. Look up for a share of greenhouse gases coming form agriculture. Had we used faster horses, that volume of emissions would be effectively doubled or tripled.

>Living creatures are a source of CO2 too, and a big one. Look up for a share of greenhouse gases coming form agriculture. CO2 emitted by horses comes from the food they eat, which is absorbed from the atmosphere in the first place by the plant when it grows. And a ton of the greenhouse gases from agriculture come from using oil, a major component of that being from tractors and crop dusters (which wouldn't exist in…

No, not really. [1]

[1]: https://timeforchange.org/are-cows-cause-of-global-warming-m...

Re: Major nuclear fusion milestone reached as ‘ignition’ triggered in a lab

#334

Post by hinkley » Tue, Oct 12, 2021, 9:04 PM UTC

MauranKilom wrote: post #148

hinkley wrote: post #62

Earlier quoted context omitted.

Heat pollution. Green house gasses are not the only way to cook ourselves. Though there are some people working on beaming heat into space, I suspect they haven’t fully accounted for heat absorption by atmospheric dust.

Hm, interesting. I was initially unconvinced that this could be a problem, but some back-of-the-envelope math says it's at least conceivable: The sun deposits enormous amounts of energy onto earth every single day: Around 340 W/m² (averaged over the whole earth), or a total of 43 x 10^15 Watts. Essentially all of it is radiated back into space (mostly as infrared). We have a temperature equilibrium because energy int…

That's assuming the anthropomorphic heat is spread evenly over the earth, rather than concentrated and creating a heat island effect.

You probably can drop an order and a half of magnitude off of that number just based on concentration. And if you don't think 'free' fusion will cause us to use several times more power than we currently use, then I don't know what to tell you.

Re: Major nuclear fusion milestone reached as ‘ignition’ triggered in a lab

#335

Post by coryrc » Tue, Oct 12, 2021, 9:05 PM UTC

brightball wrote: post #189

ohgodplsno wrote: post #160

Earlier quoted context omitted.

500 gCO2eq/kWh. Fuck natural gas. Just because coal and oil are terrible doesn't mean that it is a good option too. Build hydro, build nuclear, build wind and solar if you have money to waste. But natural gas is not a good stopgap measure while we get to fusion.

It's still less than half what's produced by coal or oil. https://www.eia.gov/tools/faqs/faq.php?id=74&t=11 There are a limited number of locations where hydro is viable and most of them have been tapped (last I read about it at least), I'm 100% with you on nuclear. Regardless of cost, we need base load capabilities when the wind isn't blowing and the sun is down. Grid storage hasn't been well proven yet. People are…

> we need base load capabilities when the wind isn't blowing and the sun is down

That's not a proper use of the concept "base load".

We used to have plants which are only cost-effective when run 24/7, but are cheaper than other kinds. The concept of "base load" is to build those kinds of plants to meet roughly the lowest daily usage so as to minimize costs.

It isn't a substitute for "capacity needed when renewables aren't generating".

Re: Major nuclear fusion milestone reached as ‘ignition’ triggered in a lab

#336

Post by megaman821 » Tue, Oct 12, 2021, 9:07 PM UTC

beambot wrote: post #150

brightball wrote: post #86

Earlier quoted context omitted.

Their carbon emissions are still dramatically lower than those of coal and oil. There are bigger fish to fry than NG. NG is likely going to be a critical transitional fuel for the planet to depend on while we get to more abundant renewable options, grid batteries and nuclear/fusion/thorium.

What time horizon are NG plants capitalized over? Soon enough, that will be a significant factor in the economic equation...

Also NG plants have the potential to burn various levels of hydrogen mixed in with the natural gas. It could be a nice compliment to areas that over-provision solar and wind and make hydrogen with the excess energy.

Re: Major nuclear fusion milestone reached as ‘ignition’ triggered in a lab

#337

Post by outworlder » Tue, Oct 12, 2021, 9:09 PM UTC

xondono wrote: post #236

humaniania wrote: post #221

Earlier quoted context omitted.

Energy subsidies for vulnerable people are an option that negates your only argument against the most sane option of switching to renewable and nuclear ASAP, at least in extremely wealthy countries like the USA.

My argument doesn’t care who’s pocket is funding the renewables. As a society, every extra dollar spent on pricier energy is an extra dollar that can’t go to social programs, or to new start up, or anywhere.

> As a society, every extra dollar spent on pricier energy is an extra dollar that can’t go to social programs, or to new start up, or anywhere.

If you are arguing to stop subsidies for fossil fuels, sure! Let's do it.

Without any subsidies and with externalities accounted for, fossil fuels would be even more expensive than renewables.

Re: Major nuclear fusion milestone reached as ‘ignition’ triggered in a lab

#338

Post by pfdietz » Tue, Oct 12, 2021, 9:15 PM UTC

rfrey wrote: post #61

Meta-question about fusion energy -something I don't understand about the movement. I spent a few years as CTO of a company providing heat-to-electricity plants. We financed and built them off high-heat plants like natural gas turbines. The "fuel" was heat going up the stack - so it was essentially free. We still couldn't compete with conventional electricity plants, even with a $30/tonne price on carbon in Canada. G…

DT fusion is not different, and is unlikely to be competitive. This was understood decades ago.

http://orcutt.net/weblog/wp-content/uploads/2015/08/The-Trou...

Re: Major nuclear fusion milestone reached as ‘ignition’ triggered in a lab

#339

Post by pfdietz » Tue, Oct 12, 2021, 9:18 PM UTC

drran wrote: post #286

zpeti wrote: post #158

Earlier quoted context omitted.

$100bn to get to a working fusion reactor doesn’t mean the second one will cost €100bn as well…

Yep, but if you want to have cheap energy, then it better to start with something cheaper, like LENR, which is still pain to reproduce, but give it $100bn and 20 years and then compare with ITER.

As long as we're in fantasyland I suggest perpetual motion machines, or perhaps unicorn power.

It's hard to make up for LENR's lack of existence with clever engineering. But even if LENR existed, how do you think it would get around the problem described? LENR would make heat, low grade heat.

Re: Major nuclear fusion milestone reached as ‘ignition’ triggered in a lab

#340

Post by pasabagi » Tue, Oct 12, 2021, 9:21 PM UTC

Mewit wrote: post #326

humaniania wrote: post #213

Earlier quoted context omitted.

"impermeable" until there's an earthquake caused by fracking and things shift deep underground where nobody can monitor or track what is happening? Seems exceptionally short sighted to me. https://www.usgs.gov/faqs/does-fracking-cause-earthquakes

I think it's best to look at the options through a risk matrix. Is it possible that an earthquake is generated by fracking that is big enough to geologically connect a hydrocarbon formation with a surface aquifer thousands of feet above it? I suppose, but I think it is very unlikely. I don't think there are any cases of that on record, and wells have been fracked in the US for many decades (although not as frequently…

Absent from your analysis is the risk presented by global warming. Obviously, transitioning the energy sources for an entire group of nations is risky and absolutely the kind of thing you expect to be a bumpy ride. On the other hand, uncontrolled global warming is far more risky - at worst, the energy shortages present a limited economic challenge. Global warming presents an existential challenge at worst, and an unbounded, extreme economic challenge at best.

The issue a lot of people have with fracking is not just the local environmental damage, but also the deeper issue of whether it's worth pouring investment into an obsolete industry that is going to produce inputs for other obsolete industries, all of which are environmentally damaging on any scale, just so you can gain a bit of energy security in the here and now. It's not just kicking the can down the road on your future energy security - it's also pushing us towards an extremely chaotic and difficult future for everybody.