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

imperial.ac.uk

181–190 of 494 posts

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

#181
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…

Natural gas is only inexpensive because of fracking. With fracking in the USA at least the people involved can set up an LLC that dissolves after the well runs out. They are not required to disclose the contents of the fracking wastewater fluid. It gets pumped back down underground where it could dissipate into the rest of the water system. These people claim that it's safe for decades when our computer models can't…

I don't think it is accurate to say it "dissipates into the rest of the water system". Typically the hydrocarbon formations being fracked are thousands of feet below the water table, separated by thousands of feet of impermeable shale. It's the same, or more so, for disposal zones where the frack fluid that flows back is injected. For the fluid to mix with a potable aquifer, it would have to leak within a wellbore. That's possible, for sure, but it's pretty rare, can be detected through proper monitoring, and can be more or less eliminated as a risk when the well is ultimately abandoned by pumping cement down the well. You don't really need a computer model to tell you what's going to happen: the formations have been separate for millions of years, and they're probably going to continue to be separate for millions more.

I hadn't heard about them using the water for crops, that is a little more alarming to me. I suspect it's not being done quite as cavalierly as you're suggesting - they are clearly treating and testing it, as discussed in the article.

In my (maybe biased) opinion, all of this should be weighed against the alternatives. Gas is much cleaner than coal, after all. In Europe, they made the decision to ban fracking, and also eliminate nuclear energy (in some countries at least). Some of the gap can be filled increasingly with renewables, but as recent history has shown, not all of it. Most of the gap is filled with Russian gas, which has its own issues. And overall it makes the energy supply less robust, which allowed their current energy crisis to happen, when the wind doesn't blow enough and the Russian supply has hiccups.

I don't think it's fair to paint this as oil and gas companies reaping all the benefits while everyone else pays the price: everyone benefits from lower energy prices, directly or indirectly. In my opinion, consumers bear some of the responsibility for environmental issues, as well as the producers.

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

#182
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…

In addition to being a large project to set up geothermal, they don't generally produce a lot of power. The largest deployment in the world is in California (The Geysers) and spans ~20 separate units, and each unit on average produces around 100 MW. A gas plant produces around 500 MW, and a nuclear plant about 1 GW.

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

#183
post #35

Earlier quoted context omitted.

>Early reports estimated that 250 kilo-joules of energy was deposited on the target (roughly 2/3 of the energy from the beams), which resulted in a 1.3 Megajoule output from the fusing plasma. Incredible progress over where they were just a couple years ago.

For reference: 1 MJ = 0.277778 kWh. Not trying to knock the progress made or anything like that, I just needed the conversion to a more familiar unit in order to appreciate what sort of scale they're talking about.

Though, when 1 MJ is generated in a fraction of a second, that does mean its instantaneous output was in the MW+ range

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

#184

Earlier quoted context omitted.

"We should put more resources into breeding faster horses now, internal combustion can wait." - someone in late 19 century.

Your analogy falls flat because we're still decades away from a functional fusion power plant. "Why breed faster horses now when maybe my grandchildren will get to zoom around in cars?"

The 1000 miles road starts with a first step, and it's not like we can't pursue several approaches at once. People like grandparent poster suggest us drop everything and concentrate on the idea he likes best. That is a very bad and harmful idea.

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

#185
post #162
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…

Very likely, each fusion plant (if they ever exist) would require, ironically, a fission plant next door to provide the power required for the magnets. The magnets, and wiring won't be cheap. The power delivery and control won't be cheap. I'm not sure how this would be amortized into the cost of the power, without making it 2-3x (or more) more expensive than alternatives. We can build, and we need, nuclear plants now…

This approach doesn't use magnets.

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

#186

Earlier quoted context omitted.

Natural gas is only inexpensive because of fracking. With fracking in the USA at least the people involved can set up an LLC that dissolves after the well runs out. They are not required to disclose the contents of the fracking wastewater fluid. It gets pumped back down underground where it could dissipate into the rest of the water system. These people claim that it's safe for decades when our computer models can't…

> These people claim that it's safe for decades when our computer models can't predict the weather accurately next week. The models may or may not be accurate but they have nothing to do with predicting the weather. There isn't any weather underground... It's all slow diffusion and buoyancy. A better starting place might be asking where the model inputs come from.

https://www.wunderground.com/

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

#187

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…

I wonder if it’s possible to create air conditioning that generates electricity. It seems like you’re removing energy from the air.

Do you mean a heat engine?

Because the "opposite" of air conditioning is just a heat engine (taking "hot" and "cold" source, and using the difference to generate locomotion). In fact, all engines are glorified heat engines: be it a steam turbine, ICE, geothermal, or whatever

When air gets hot, it expands. When air gets cold, it contracts. So heat up air through some mechanism (hot side) to push a piston up. To pull the piston down, either use momentum or the cold-source (cold air contracts, pulling the stuff down).

The sterling engine is the best general purpose demonstration of this, and you can buy such engines for $20 to $100 or so.

ICE engines use gasoline as the hot source. Steam engines use steam (water at 100C) to transfer the heat from the hot source to the needed locations (heat can be from nuclear, coal, or other sources)

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Air conditioning is just this process in reverse. Expand the air forcibly by applying force to the piston. This cools down the air. "Gather" the coldness through some mechanism, which heats up your air inside the A/C unit while cooling whatever is on your "cold plate".

Push the hot air and compress it down. This heats up the air even further: "transfer" the hotness through some mechanism (aka: heat something else up, like the air outside the house). This cools down the air inside your A/C unit.

Now find a fluid that's more efficient at this process than oxygen. Then realize that fluid is terrible for the Ozone layer and write a regulation for a newer, crappier fluid that's less damaging to the Earth, and you have modern A/C units.

> It seems like you’re removing energy from the air.

You're just transferring the hotness somewhere else. Go feel the air that your refrigerator outputs: its far hotter than the air inside. If you measure the energy, its the energy that was "stolen" from inside the refrigerator + the energy "spent" on the heat pump (that compression / decompression cycle takes work, and work generates heat)

We can transfer heat around, but it costs energy. Alternatively, a difference in heat can be used to gather energy, but it will "Average" the temperatures and eventually the hot-source and cold-source will be the same temperature.

We can use fuels to make the hot-source stay really, really hot for long periods of time (as long as we have a source of fuel), and that's basically the design of steam engines / heat engines.

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

#188

Earlier quoted context omitted.

Natural gas plants are cheap but they cause global warming, so soon we will not be able to use them. For example, the U.S. target is to have zero carbon emissions from electricity generation by 2035, and zero carbon emissions at all by 2050.

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.

The existence of natural gas keeps electricity prices low, which disincentives research into other power generation methods.

In a capitalist world, "lets do this until that is ready" plans usually just end up delaying 'that'.

A massive tax on carbon would mean we can all pay for 'this', until 'that' has been developed and we can enjoy low prices again.

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

#189

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.

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 actively fighting nuclear and the costs as well as timeliness are crazy. If there's one thing in this country worth wasting money on, it's nuclear.

If we can't get base load generation from nuclear due to all of the financial risks, NG is about all that's left to carry the load as an improvement over coal and oil.

I'd much rather have zero emission nuclear, but NG is the stop gap that we are left with until we start committing to nuclear (or we have a better round-the-clock option).

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

#190
post #162
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…

Very likely, each fusion plant (if they ever exist) would require, ironically, a fission plant next door to provide the power required for the magnets. The magnets, and wiring won't be cheap. The power delivery and control won't be cheap. I'm not sure how this would be amortized into the cost of the power, without making it 2-3x (or more) more expensive than alternatives. We can build, and we need, nuclear plants now…

NIF doesn’t use magnets. Pure inertial confinement. You’re thinking of Tokamaks. Those use superconducting magnets.

Superconducting magnets like ITER uses don’t require energy to continue running as they, of course, are superconducting. They “only” have to dump heat put into them by the reaction radiation. The SPARC reactor by MIT is similar but much smaller by using Cuprate superconductors (high temperature superconductors, but here operated at much lower temperatures to increase the critical field) that allow much higher field strengths. They often have non-superconducting joints which cause a (sort of) small amount of additional heat that needs to be dumped, but it is possible to make such joints superconducting as well. Anyway, all such designs for commercial scale power from Tokamaks use fusion generated electricity to power the magnet cooling, and those electricity requirements are less than the electricity produced.

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