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

imperial.ac.uk

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

#421

Post by eutropia »

xondono wrote: post #222
thescriptkiddie wrote: post #212

Earlier quoted context omitted.

The unpopular truth is that fossil fuels are far too cheap. If the negative externalities were priced in, they would be at least twice as expensive, perhaps as much as ten times.

> If the negative externalities were priced in they would be at least twice as expensive Quotation needed

Current carbon capture tech charges about $500/ton (but this number is bound to get lower) of CO2, given the CO2 produced per KWh of Natural gas is 0.41kg/KWh, that adds about $0.20 per KWh to your electricity bill. Where I’m from, our mostly natural gas electric company charges $0.10/kwh. So adding $0.20 does indeed do more than double it (for now).

[1] https://www.eia.gov/tools/faqs/faq.php?id=74&t=11

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

#422

Post by rfrey »

08-15 wrote: post #331
rfrey wrote: post #118

Earlier quoted context omitted.

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?

Those temperatures will also be at higher pressures, while the waste heat I mentioned is at atmospheric pressures. 500-600C is the "crossover zone" where ORC versus steam cycle really depends on the details.

The plants we were looking at were either open cycle turbines (which means turbines in mechanical duty such as compressor stations, since all new turbine power plants are combined cycle) or other industrial processes such as cement production and steel manufacture.

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

#423

Post by xyzzyz »

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…

Why couldn't you compete? Where was the expense in your system? Guessing, it was mostly the equipment to extract the waste heat, wasn't it? What if that equipment was 10 times cheaper, could you compete then? If you there was large demand for your system, you could produce your equipment in huge volumes, and bring down unit costs enormously, no?

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

#424

Post by xyzzyz »

learc83 wrote: post #323
meltedcapacitor wrote: post #180

Earlier quoted context omitted.

Yes, but bulk of the demand is heat and industry, so you're quickly back to having to build a lot of "storage" in the form of buildings with high thermal inertia and spare capacity for production, so that you can keep the high energy plants idle at inconvenient times. Hard to say if that is more efficient than building actual energy storage. Every little helps I guess, but getting people not to shower on cloudy days…

You could just implement enough surge pricing that people/companies work around peak times on their own and build their own storage.

Industry often works around the clock already. You don't want to buy and install three times the equipment you need, and have it sit idle 16 hours of the day. You also don't want to shut down for winter just because the electricity is less abundant then.

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

#425

Post by xyzzyz »

thow-58d4e8b wrote: post #308
dragontamer wrote: post #104

Earlier quoted context omitted.

The benefits of a car were immediately obvious as soon as supply lines were considered. Feed for horses was something like 30% of all deliveries in a horse-based supply chain. Railroads run off of coal, but steam-engines were huge. ICE engines were miniature engines that also ran off of a fuel source (eventually settling upon oil, but many different fuel sources were considered in those early days, including electric…

> ICE engines were miniature engines that also ran off of a fuel source (eventually settling upon oil, but many different fuel sources were considered Fun fact - Rudolf Diesel's first engines were running on cooking oil. In fact, many diesel engines can operate on vegetable oils without modifications (not long term though). That sounds odd, but from the perspective of "burn hydrocarbons to generate heat", petrol, die…

Here's a classic Top Gear on it: https://www.youtube.com/watch?v=1lqCwNReU1Y

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

#426

Post by xyzzyz »

after_care wrote: post #144
einpoklum wrote: post #114

Earlier quoted context omitted.

Well, if we'd have gone down that road, plus strong environmental awareness, maybe the Earth wouldn't be warming up so badly right now, and the oceans wouldn't have islands of plastic (= oil) waste. Now, sure, we wouldn't have enjoyed some of the benefits of car technology, but - public transport (esp. trains) makes up for a lot of that. OTOH, public transport pollutes too.

I’d much rather take an ICE train than a steam engine train…

Especially when it's the Comet train entering the Taggart Tunnel.

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

#427

Post by snypher »

tsimionescu wrote: post #411
smaddox wrote: post #402

Earlier quoted context omitted.

1 MJ is enough to vaporize roughly half a liter of water that started at room temperature. That's nothing to sneaze at. Obviously you would need to do with a high rate (e.g. once per second) in order for it to be viable for power production. No reason the lasers couldn't do that. The challenge is making the pellets cost effective at scale. Currently, they cost something like $10k each.

The bigger problem is the precision-machined hohlraum the pellets sit in for ignition. That costs millions of dollars, is crucial for actually achieving anything, and is destroyed in the process.

I wondered why these things were so expensive until I read:

-literally made of gold or uranium

-walls must have surface roughness less than 1 micron

Are there other reasons too? I'm not sure where to find machinable uranium on McMaster

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

#428

Post by tlb »

smaddox wrote: post #402
ClumsyPilot wrote: post #371

Earlier quoted context omitted.

The capsules are tiny and do not generate usefull amount of energy. ITER is planned to generate 500,000,000W. Thats actually usefull

1 MJ is enough to vaporize roughly half a liter of water that started at room temperature. That's nothing to sneaze at. Obviously you would need to do with a high rate (e.g. once per second) in order for it to be viable for power production. No reason the lasers couldn't do that. The challenge is making the pellets cost effective at scale. Currently, they cost something like $10k each.

1 MJ per second is 1 MW, a power level typical of portable diesel generators. Conventional nuclear plants are hundreds of megawatts each.

Apparently it is quite hard to repeat the laser blast quickly, because the optical system heats up during a pulse causing the beams to deflect as the materials expand and contract due to temperature. The NIF design requires dozens of laser beams to align precisely on a very small pellet in the middle of a large cavity. If you fire it a second time before it completely cools down the beams will hit the pellet slightly off-center and you won't get the compression needed for efficient fusion.

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

#429

Post by elihu »

Symmetry wrote: post #103
Mizza wrote: post #72

Earlier quoted context omitted.

It's political. Taxes on carbon pollution are inevitable, but for the time being there is still political blockage because of the power of the cartels.

Politically the problem is that voters want action on climate change but aren't willing to pay any visible cost associated with that action. If you put a tax on carbon that raises the price of something by $100 then that's a political no-go. But if you create a cap and trade system that raises the price by $150 that might be politically viable. Not ideal, but one has to compromise with political realities.

I think resistance to a carbon tax is more complicated than that, at least in the U.S.. You've got a large and vocal minority that doesn't believe climate change is an issue in the first place. Of the people that are concerned about climate change, some are worried about the cost to themselves, and some are worried about the cost to others. I'm pretty well off (not wealthy, but middle-class) and I don't think a carbon tax would affect me much at all. But for some people it would be a big deal. I'm in favor of a carbon tax, but I understand the argument that it's recessive and is basically paid out disproportionally by the poor, because they spend a larger percentage of their income on gas and electricity.

I think a carbon tax offset by a tax credit for lower-income taxpayers would be a reasonable option.

I see cap-and-trade as the sort of arbitrarily-complicated system that Congress creates when they want to shake down an industry for campaign contributions. If it gets us less CO2 emissions I guess it's worth it, but still it's kind of gross.

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

#430

Post by thehappypm »

Robotbeat wrote: post #211
thehappypm wrote: post #198

I'm struggling to understand what exactly happens. The deuterium and tritium mixture is hydrogen -- so it is a gas? So is it in some sort of gas-containing container, that also lets laser light through -- probably some kind of glass container? What kind of glass container can survive having this much energy pumped through it, and such a hot gas inside it? https://en.wikipedia.org/wiki/Fusion_ignition

It’s actually frozen deuterium tritium. Inside a small pellet blasted by X-rays which compress the pellet until it’s hot and dense enough for the fusion energy produced to continue burning and heating the deuterium/tritium until much more energy is produced than the energy of the X-rays. It all happens in an instant. The pellet’s structure doesn’t survive. But it happens fast enough that just the inertia of the pelle…

How do you freeze hydrogen?
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