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

#231

Post by nightski » Tue, Oct 12, 2021, 7:03 PM UTC

humaniania wrote: post #217

Mewit wrote: post #181

Earlier quoted context omitted.

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. T…

Also maybe read the entire article on using fracking wastewater on crops: Until now, government authorities have only required limited testing of recycled irrigation water, checking for naturally occurring toxins such as salts and arsenic, using decades-old monitoring standards. They haven’t screened for the range of chemicals used in modern oil production. No one knows whether nuts, citrus or other crops grown with…

This is surprising to me because in North Dakota there have been plenty of brine spills (from storage tanks) and it seems to destroy the farmland. It's nearly impossible to clean up and it always makes its way into major waterways.

I can't believe a farmer would intentionally use this to water their crops, it wouldn't make any business sense.

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

#232

Post by xondono » Tue, Oct 12, 2021, 7:06 PM UTC

micromacrofoot wrote: post #224

xondono wrote: post #214

Earlier quoted context omitted.

What a great way to not answer what OP is asking. If you don’t like fracking, that’s alright, but sustaining ourselves without it it’s not really an option. Right now our options are: 1) Use coal, accept the consequences of the increased climate change. 2) Keep using gas, reduce the future costs of climate change, deal later with the speculative consequences you mention. 3) Switch to renewables and drastically increa…

> Switch to renewables and drastically increase energy costs, which will trap millions of people into poverty, and put millions more in risk This feels like a bad faith take out of the gate (whether or not it's intended)... are there no mechanisms for subsidies to abate these issues? are renewables more likely to increase wealth gaps than other fuels?

It’s just simple arithmetic, however you want to subsidize or socialize the cost, the fact is that renewables have higher cost per MW.

Every dollar spent on higher energy costs is a dollar not spent in other things. This will impact growth.

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

#233

Post by lazide » Tue, Oct 12, 2021, 7:07 PM UTC

rfrey wrote: post #199

Animats wrote: post #163

Earlier quoted context omitted.

Doing something with low-grade heat is hard and often futile. E = (Th-Tc)/Th. Look at a gas turbine. There's a succession of turbine wheels, getting larger towards the end. Each is running off the exhaust of the previous wheel, at a lower pressure. If you added another, larger, turbine wheel at the end, you'd get a little more energy out, at higher machine cost. The turbine ends where adding another wheel is not cost…

Exhaust from a gas turbine for a pipeline compression station is around 600C at about 95kg/second. That flow contains about 100MW of heat energy, which can be captured with Organic Rankine Cycle (like steam cycle, but using organic fluids like cyclopentane as a working fluid to better match the thermodynamics) about 20% of that can be converted to electricity. This is off-the-shelf tech. The problem isn't the technol…

The parent was pointing out that the economics are also a fundamental limit of the technology/physics.

If you can do a lot of work with expensive machines to get 20MW from that plant, but you can also do less work and spend less money getting an extra 20MW by burning some cheap primary fuel (with higher quality heat/aka a bigger delta), then they’re just going to burn more primary fuel. It’s a bit silly to do it any other way (barring legislation or market pressures or whatever) if you care about the amount of energy you are getting for the money you are paying.

And that is a fundamental issue, as reclaiming energy from secondary heat is always going to be less ‘nice’ than from the primary fuel.

If you can do it easily enough that it doesn’t add a lot of extra cost, then chances are the primary turbine/power system could be built efficiently enough to not throw that waste heat out the back in the first place. They do so because the math doesn’t check out generally.

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

#234

Post by ChuckMcM » Tue, Oct 12, 2021, 7:07 PM UTC

rfrey wrote: post #199

Animats wrote: post #163

Earlier quoted context omitted.

Doing something with low-grade heat is hard and often futile. E = (Th-Tc)/Th. Look at a gas turbine. There's a succession of turbine wheels, getting larger towards the end. Each is running off the exhaust of the previous wheel, at a lower pressure. If you added another, larger, turbine wheel at the end, you'd get a little more energy out, at higher machine cost. The turbine ends where adding another wheel is not cost…

Exhaust from a gas turbine for a pipeline compression station is around 600C at about 95kg/second. That flow contains about 100MW of heat energy, which can be captured with Organic Rankine Cycle (like steam cycle, but using organic fluids like cyclopentane as a working fluid to better match the thermodynamics) about 20% of that can be converted to electricity. This is off-the-shelf tech. The problem isn't the technol…

In that context think of this this way, if cost of converting methane into heat is 1 currency unit per joule of heat produced, fusion is hundred times as expensive but produces a million times more heat so the cost per joule is one ten thousandth of the cost from methane.

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

#235

Post by giaour » Tue, Oct 12, 2021, 7:07 PM UTC

myself248 wrote: post #108

adrianN wrote: post #89

Earlier quoted context omitted.

PV+storage is how many hours of storage? Storing enough power to last a night is just getting close to commercially viable afaik, but storing enough power to last a winter is still quite expensive.

The best storage is no storage at all, it is demand-response. Things like responsive appliances and EV chargers that can schedule their load rather than insisting that limitless power be available instantaneously. I don't care when the dishwasher runs as long as the dishes are clean by tomorrow, you know? Of course right now, putting the word "smart" on an appliance doesn't imply any of that, and the way it ends up i…

Nitpicky, but shouldn’t this pattern be called “supply-response” (as in, appliances programmed to respond to a supply glut) “Demand-response” sounds like it should be used for power sources that only spin up when demand exceeds the production rate.

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

#236

Post by xondono » Tue, Oct 12, 2021, 7:10 PM UTC

humaniania wrote: post #221

xondono wrote: post #214

Earlier quoted context omitted.

What a great way to not answer what OP is asking. If you don’t like fracking, that’s alright, but sustaining ourselves without it it’s not really an option. Right now our options are: 1) Use coal, accept the consequences of the increased climate change. 2) Keep using gas, reduce the future costs of climate change, deal later with the speculative consequences you mention. 3) Switch to renewables and drastically increa…

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.

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

#237

Post by jhgb » Tue, Oct 12, 2021, 7:10 PM UTC

cletus wrote: post #164

bigfudge wrote: post #157

Earlier quoted context omitted.

> photos created at the Sun's core take ~30,000 years to escape I’m guessing you meant photons but this still seems amazing. Is there somewhere I can find out more about that?

So this is based on mathematical modeling. Here's one reference I found [1] that estimates 5,000 years. I know I've heard 30,000 too, which is really within the same order of magnitude. [1]: https://sciencing.com/fun-sun-moon-stars-8459789.html

When I was younger (like three decades ago), the number I was taught was something like two million years (if I remember it correctly; I might still be able to find that book if I'm lucky).

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

#238

Post by gene-h » Tue, Oct 12, 2021, 7:11 PM UTC

tsimionescu wrote: post #105

gene-h wrote: post #20

Earlier quoted context omitted.

What's important here is that they may have achieved ignition, that is making the fusion reaction self sustaining[0]. Once it becomes self sustaining one should be able to add more fuel to the pellet to get more energy out for the same input energy. It's worth noting that NIF was not intended to generate power and is not representative of a potential power plant. The lasers on NIF are old and were chosen to have a lo…

> Once it becomes self sustaining one should be able to add more fuel to the pellet to get more energy out for the same input energy. That's not how ICF works. Plasma, being a gas-like state, will always expand to fill whatever volume is presented. With ignition, the rate of expansion is essentially lower than the rate of fusion, allowing you to fuse all of the fuel before the plasma dissipates and cools down. In ICF…

This report found that ICF could reach LCOE as low as $25/MWh "with optimistic but not obviously unrealistic inputs."[0] This does require hohlraums cost about $2 each and are fired every 20 seconds. With mass production and process optimization it may not be ridiculous to reduce hohlaum cost to this amount. However, the yield is about 5 gigajoules which is equivalent to about 1 ton of TNT.

Making equipment that can handle 1 ton of TNT exploding every 20 seconds is an interesting engineering challenge.

[0]https://royalsocietypublishing.org/doi/10.1098/rsta.2020.005...

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

#239

Post by micromacrofoot » Tue, Oct 12, 2021, 7:12 PM UTC

xondono wrote: post #232

micromacrofoot wrote: post #224

Earlier quoted context omitted.

> Switch to renewables and drastically increase energy costs, which will trap millions of people into poverty, and put millions more in risk This feels like a bad faith take out of the gate (whether or not it's intended)... are there no mechanisms for subsidies to abate these issues? are renewables more likely to increase wealth gaps than other fuels?

It’s just simple arithmetic, however you want to subsidize or socialize the cost, the fact is that renewables have higher cost per MW. Every dollar spent on higher energy costs is a dollar not spent in other things. This will impact growth.

Sure, but aren't fossil fuels also subsidized? Haven't the costs been reduced due to the economies of scale and time? Are the environmental downsides not considered part of the cost?

I get it, renewables are still more expensive, but are they really doomed to trap more people in poverty?

Couldn't one argue that the unbalanced economic systems are the primary thing that traps people in poverty and the cost of energy is simply a minor factor? There are certainly countries with low energy costs and high poverty rates.

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

#240

Post by malchow » Tue, Oct 12, 2021, 7:12 PM UTC

solarhoma wrote: post #215

humaniania wrote: post #102

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…

There is a lot wrong with your post. >They are not required to disclose the contents of the fracking wastewater fluid. Majority of water used in hydro fracking is slick water. This is normal water with friction reducers added to it. Typically 1%. Though can change based on the design of the frack. These are maybe not disclosed to the public since they typically are proprietary formulas that each vendor creates on the…

He's also wrong about there being a water *shortage* in California. There is water *diversion*, designed by environmentalists to save animals, that strips farmers of water.