What are your perspectives on peaceful clean nuclear FUSION projects?

[cdev]

That is of course a sort of Holy Grail for energy researchers. The way our sun produces energy. Could it happen and be controllable?

[Kleinstein]

The technical side looks like it is possible, though difficult. However I am not so sure it will be economic. At least with the concepts planed so far it will likely not be cheap energy.  The big problem it the long time still needed for development: if everything works out well, they promise something like 50 years (this number was not that different 0 years ago  ). Even than it would not be an instant breakthrough and than convert everything to fusion - there is a limited supply of tritium and thus an expansion to large scale would take quite some time (e.g. another 50 years).

However we need alternative energy source much earlier - so chances are it comes 50 years too late.

[PartialDischarge]

I'd be happy if I could only understand how the sun has been working for so long considering it burns 620 million metric tons of hydrogen each second

[cdev]

Well, in the distant future it will eventually be used up.  By then we hopefully will have developed alternative places to live.

[filssavi]

I'd be happy if I could only understand how the sun has been working for so long considering it burns 620 million metric tons of hydrogen each second

It just has a Big-Ass(tm) fuel tank

Also it doesn’t just fuse Hydrogen into helium it goes all the way up to iron before burning out

[T3sl4co1l]

I'd be happy if I could only understand how the sun has been working for so long considering it burns 620 million metric tons of hydrogen each second

It just has a Big-Ass(tm) fuel tank

Also it doesn’t just fuse Hydrogen into helium it goes all the way up to iron before burning out

The Sun will end with helium, IIRC.  Heavier stars do more, carbon being the next major step, then everything after goes in fast enough stages that you get a mix, including heavier stuff being made in the core.  The heaviest stars (like, 50+ solar masses) go all the way to iron in the core, then explode in a supernova (the core collapsing to a neutron star in the process, or possibly a black hole).

Tim

[timgiles]

Fusion will happen eventually - but it wont ever be clean. Cleaner prehaps, but not clean.

[james_s]

Fusion has been about 10 years out for my entire life. It would be cool to see it happen but I'm not holding my breath.

[rfeecs]

It's the technology of the future... and always will be?

There are so many projects, ITER among them, but will it ever be economically viable?  This guy says no:

https://matter2energy.wordpress.com/2012/10/26/why-fusion-will-never-happen/

[Kleinstein]

It's the technology of the future... and always will be?

There are so many projects, ITER among them, but will it ever be economically viable?  This guy says no:

https://matter2energy.wordpress.com/2012/10/26/why-fusion-will-never-happen/

The comparison in the link is flawed, especially with PV: You can't compare watts peak, but you have to take into account that some sources only produce power a short time of the day. For PV this is something like a 10-30% power factor - which increases the costs for the energy produced by a factor of 3 to 10, even more in winter of very unfavorable places. The second point is that with a variable power sources you need storage - with something like PV this can be quite a lot, up to the point of another factor of about 3 in the energy costs. The storage part can be lowered if there is a mixture of sources. Also wind is more favorable, as it often has a better power factor and less seasonal storage needed.  Still you can't compare peak power - there is still another factor of maybe 3 to 10 to get average coste with storage / buffering.

The cost for the lithium blanket is one big factor - though I am not sure the $180 / kg number for Li-7 would really apply. It still gets expensive.
The second big cost factor I imagine in the likely limited lifetime of the container material due to radiation damage.  Even new Mo based materials will not last for ever. Replacing the container is kind of tricky: it will be radioactive, at least for the first few years. It's a toroid, with all the superconducting magnets around, so the access it really difficult, it has to be really tight (e.g. welded in place) so that it can hold the high vacuum and it likely has to stand the high temperature (needs to be hot to use the energy) of the Li blanket.

[KrudyZ]

Tony Seba has something interesting to say about this:
https://www.youtube.com/watch?v=2b3ttqYDwF0&feature=youtu.be

He believes that NOTHING will be able to compete with local solar plus battery storage a few short years from now.
This includes any centralized power plants even if they could run for free.
The reason is that you can't get away from the cost of power transmission, which he puts at $0.07 per kWh.
When (or arguably if) solar on the roof plus storage goes below that other solutions no longer make any sense.

[helius]

It's a toroid

Only for Tokamak designs like ITER, not the other designs that look like they will break even using markedly less complicated facilities.

[james_s]

$0.07 per kWh sounds a bit high for distribution costs. I only pay about $0.08 per kWh so that wouldn't leave much left to pay for the power plants or allow for some profit for the utility.

[KrudyZ]

$0.07 per kWh sounds a bit high for distribution costs. I only pay about $0.08 per kWh so that wouldn't leave much left to pay for the power plants or allow for some profit for the utility.

Do you live next to a power plant?
We get charged $0.20 base rate and $0.27 tier 2 rates...

[james_s]

I guess it depends on what one considers to be "near". I'm a little more than 200 miles from the Grande Coulee Dam, a major hydroelectric plant.

[KrudyZ]

Well, I guess you're lucky. Washington State has the lowest electricity cost in the U.S.

http://www.neo.ne.gov/statshtml/204.htm

[Rerouter]

The biggest issue with fusion, is that you dont just need to beat the sun, you need to beat its power output per unit volume by many many many times to stand to make a usable amount of power, like the comparisons between the suns core and a compost pile.

equally you need to force things to happen much faster than the current reaction rate, for power production we dont want the chance of any 1 atom fusing with another taking between millions to billions of years, we would prefer within seconds, or minutes.

is clean fusion a good thing for humanity if it works: yes,
Is it currently hard to get a net positive while still powering the containment feilds: yes

[helius]

I think "clean fusion" would necessarily be D-D fusion. Using tritium means that you bombard something with intense neutron radiation, likely turning it into nuclear waste.
D-D fusion is even farther in the future than sustainable D-T fusion.

[EEVblog]

That is of course a sort of Holy Grail for energy researchers. The way our sun produces energy. Could it happen and be controllable?

It's possible and it works. It's just not efficient (yet).

[james_s]

Well, I guess you're lucky. Washington State has the lowest electricity cost in the U.S.

http://www.neo.ne.gov/statshtml/204.htm

That may explain why I see so many electric cars on the roads around here. I knew it was cheaper than some parts of the country but I hadn't seen a widespread breakdown.

On the other hand we have some of the most expensive gasoline in the nation.

[Rutherfordium]

I read something before that the waste heat from fusion would warm the world way more than catastrophic climate change, and that it makes it unviable.

I don't know where to start with back of the envelope calculations to analyze that idea, though.

[GreggD]

This long video says it all except how to get 100 million degree C waste helium out of the device.

MIT's Pathway to Fusion Energy (IAP 2017) - Zach Hartwig - YouTube

[james_s]

I don't see how the waste heat would be any more than any other method of electricity generation. If you have a source of heat significantly warmer than ambient, you can extract that energy for useful purposes. Coal and nuclear plants all just produce heat which is turned into electricity.

[ez24]

That is of course a sort of Holy Grail for energy researchers. The way our sun produces energy. Could it happen and be controllable?

Yes, it is called the big bang.  Controllable - yes if you think of it as creating the universe.  Who is to say it wasn't a life form's experiment.  So maybe someday an earthling will make the next big bang.

[T3sl4co1l]

I had estimated that by about the 2500s, we'll have to throttle back world fusion production otherwise climate change will occur by sheer force of output power being a sizable fraction of solar output.

Orbital sun shades will probably be a thing by then.

Tim