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U.S. physicists rally around plan to build fusion power plant

sciencemag.org

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Re: U.S. physicists rally around plan to build fusion power plant

#51

Post by acidburnNSA »

Hasz wrote: post #49
tahoeskibum wrote: post #4

I think that solar/wind + battery (e.g. Tesla Megapack) will make fusion irrelevant.

No one is giving you numbers for why this is wrong, so let me ballpark. Typical solar irradiance is 1000W/m^2. Mean sunshine hours where I live is 3000hrs/y. Assuming 100% efficiency, 100% solar irradiance, perfect angle etc for those 3000hours, we get ~10^10J of energy. Those are bad assumptions, but very generous. In a gram of deuterium, per e=mc^2, we get ~10^12J. There is 100x more energy in a single gram of dete…

If energy density were proportional to cost, nuclear fission would already be dominating by a factor of 2,000,000x over fracked gas and coal. The reality is that complexities of systems needed in energy conversions end up coming into play. Getting net energy out of fusion was done in the 1950s (explosively, but still). Even given sustained controlled fusion, you still have to build a power plant around it and 'break even' on costs.

Re: U.S. physicists rally around plan to build fusion power plant

#53

Post by gpm »

trhway wrote: post #30
gameshot911 wrote: post #17

2040s? 20+ years from now!?! Too fuckin slow!! For all Musk's faults, he recognizes such timelines are untenable, and pushes people to do the 'impossible'.

And fortunately soon Musk will need fusion for Mars travel and colonies. He just personally got extra 100B to burn - i think SpaceX will start to hire nuclear scientists and engineers soon :)

Fission seems like the better option for mars. The technology is ready now, and no one cares about a bit of nuclear waste on mars anyways.

Re: U.S. physicists rally around plan to build fusion power plant

#54

Post by gpm »

Hasz wrote: post #49
tahoeskibum wrote: post #4

I think that solar/wind + battery (e.g. Tesla Megapack) will make fusion irrelevant.

No one is giving you numbers for why this is wrong, so let me ballpark. Typical solar irradiance is 1000W/m^2. Mean sunshine hours where I live is 3000hrs/y. Assuming 100% efficiency, 100% solar irradiance, perfect angle etc for those 3000hours, we get ~10^10J of energy. Those are bad assumptions, but very generous. In a gram of deuterium, per e=mc^2, we get ~10^12J. There is 100x more energy in a single gram of dete…

This ignores the enormous cost involved in building and maintaining the machines to fuse that deuterium and capture the resultant energy.

You might end up being right, but I think it's actually very far from clear that fusion will ever win on cost.

Re: U.S. physicists rally around plan to build fusion power plant

#55

Post by jdeibele »

orthecreedence wrote: post #29
kortilla wrote: post #25

Earlier quoted context omitted.

Fission is a solved engineering and science problem though and we’re still blocking it to let the sea levels rise. Point being, nobody actually cares about climate change enough to make hard decisions so a Manhattan style project is highly unlikely.

Yes, I've been saying it over and over: raise the price of oil until gasoline et al are $20+/gallon. Then nuclear will be cheap . Why are we letting a silly thing like scarcity, supply, and demand dictate whether we self-destruct?

I've been saying for a long time that the US should increase the tax on gas steadily every year. Even a nickel a year would be OK but more would be better.

People would be able to plan on the price increasing every year and make sound economic decisions on whether they wanted to move closer to work, etc.

Unfortunately, it became apparent about the same time that the US is almost incapable of doing something in an organized fashion. People would scream about the price of gas going up and it would be rolled back. Or there'd be subsidies that would negate the tax increases.

Re: U.S. physicists rally around plan to build fusion power plant

#56

Post by gbh444g »

garmaine wrote: post #33
howardr wrote: post #21

Earlier quoted context omitted.

I read a letter in the Financial Times over the weekend... > Forty years ago, when studying for my engineering degree, I learnt a rule of thumb that said that nuclear fusion is always 20 years away. I was therefore reassured by the date given in the report (“Sites sought for Step change in energy supply”, December 3) for the Step nuclear fusion plant — 2040. (Edit: Unfortunately it’s behind a paywall but will include…

For most of my life fusion has been perpetually 30 years away. Now it is only perpetually 20 years away. That's progress!

So the horizon is approaching us at a what? logarithmic scale? What can we infer from this about the topology of the planning surface?

Re: U.S. physicists rally around plan to build fusion power plant

#57

Post by sam »

spo81rty wrote: post #15

Meanwhile, reportedly China has already built one and is testing it now. So the USA is 20 years behind?

I’m guessing you’re referring to HL-2M which indeed in testing. But that tokamak is not designed to generate electricity but rather to study long pulse durations (~5s) at reactor relevant temperatures.

Re: U.S. physicists rally around plan to build fusion power plant

#58

Post by mchusma »

garmaine wrote: post #33
howardr wrote: post #21

Earlier quoted context omitted.

I read a letter in the Financial Times over the weekend... > Forty years ago, when studying for my engineering degree, I learnt a rule of thumb that said that nuclear fusion is always 20 years away. I was therefore reassured by the date given in the report (“Sites sought for Step change in energy supply”, December 3) for the Step nuclear fusion plant — 2040. (Edit: Unfortunately it’s behind a paywall but will include…

For most of my life fusion has been perpetually 30 years away. Now it is only perpetually 20 years away. That's progress!

Both ITER is scheduled to be done and SPARC are trying to make net energy in 5 years. They probably won't hit those dates, but we aren't really talking about 20 years anymore. (I agree with several commenters on this thread that any project with a 20 years to completion timeline should be shelved for things with <10 year timelines).

Re: U.S. physicists rally around plan to build fusion power plant

#60

Post by logicchains »

free_rms wrote: post #20
wcarss wrote: post #12

Serious question: how does an article like this get written without mentioning SPARC[1] once? They're hardly secretive, they're MIT's people, they're moving on a plan to get results in ~5 years, and they're talking about the same kind of things: tokamaks, better computer modeling, and easier to make higher temperature superconductors for stronger magnets. I'm just a layperson, I only know pop science level stuff here…

God I wish we could Manhattan Project this shit. I'm a layman too but I get the impression that the theory is basically there and we just need to figure out the engineering. That's a solvable problem with lots of money and lots of teams. Are we going to wait until the sea level rises 20 feet and then say, geez, compared to the costs this imposed, fusion would have been easy?

>God I wish we could Manhattan Project this shit.

Interesting point of reference: the Manhattan project cost around around $25 billion in today's dollars. The US government spent at least $6 trillion on the coronavirus response, which could buy 200 Manhattan Projects. Coronavirus will kill around a million people this year at most; air pollution kills around five million per year (and sea level rises could kill a lot more).

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