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Real power fusion

Posted: Fri Mar 25, 2016 6:02 pm
by Richard Hull
I suppose the usual amount of hoopla around fusion energy will continue forever. However, a realist's approach needs to be made in the light of hard facts and energineering issues. This is in response to the "perfesser's" current lament about fusion on the home page.

It is understood that a number of high powered, high priced efforts in the 50 million dollar price range and up to billions have actually done what is claimed as over unity fusion plasma generation and held it for some minute or two time frames.

What are the current issues and time frames?

1. The short duration is due to forced shutdowns for any number of "we can't go any longer" issues. These issues are "we broke or damaged something" or "the control mechanism was getting highly unstable and we didn't want to break anything". This tells all logical thinkers that they are not even close to a 24-7-365 over unity fusion system. Honest time frame for a 24-7-365 net energy experiment fusion reactor that is still not viable for power generation? God only knows! However, the fact remains they aren't even close.

2. Let us assume that at some future date some experimental reactor does do 24-7-365 fusion at net gain. What is its coefficient of performance? (COP in the energy biz) This all important factor will either drive or crush the commercial power industry to embrace or laugh at the fusion success story. Too low a COP and the money for development just won't be there. Time frame here is instantaneous! either it is efficient or it is not.

3. Let us further assume that after all the addition math of energy input demands to do the 24-7-365 fusion has a cop of 10 or better and the commerical suppliers are happy with this.... Now the bean counters come in......Stand back folks! What is the cost per kwhr to just construct the COP 10 fusion plant of 10 megawatts, plus the 1 megawatt driver/startup/backup, fission, coal or natural gas plant needed to start, run and backup the 10 megawatt fusion plant? If the costs exceed 100% of the current rate of delivered power, it is a non-starter. Time frame here? Probably 10 years as the technology and more experimental reactors attempt to better the performance and the industry looks real close at costs, long term, as two plants might be needed for viable, reliable fusion power.

4. Finally let us take a huge leap forward and say that at some late date all three of the above road blocks melt into oblivion and the experimental reactor can run virtually forever, has a COP of 100+, is fully capable of feeding its own output back to power itself with good distributable energy to spare and is attractive financially to build. How many years will pass after all the foregoing is achieved before the first watt of commercially produced fusion energy will flow out of the first home's wall outlet? A good estimate here would be on the order of the "fission to commercial power" time frame. 20-30 years before at least one plant goes on line (Shippingport). Perhaps 40 years before a good number of plants come on line.

The bottom line here can be readily stated. No newborn taking his first breath now, as I type this missive, will live long enough to see fusion energy flow out of his wall outlet! In short "Be advised all ye that readeth this, that thou shalt not see fusion energy during thy life upon this earth."

.....Then, there is always that lucky donkey.....that monkey wrench flying into the face of convention....that fly in the ointment of establishment fusion.....

We have lived almost 80 years since the discovery of fusion and will continue to live without it producing a watt of consumable electricity for a long time to come. The promises of, and claims for, a bright fusion energy future will continue to flourish, be assured of that.

I felt it was time for another "downer".

Richard Hull

Re: Real power fusion

Posted: Fri Mar 25, 2016 8:50 pm
by JoeBallantyne
Thanks Richard, we all needed that. :-)

Re: Real power fusion

Posted: Tue Mar 29, 2016 5:42 pm
by Dennis P Brown
Good post but not all is as bad as what you say. A stellarator can run 24/7 (latest news on the Wendelstein-7X): ... ein-x.html ) But if it does progress pass this first step, can it even make break even? As you correctly point out, that is yet to be determined. Yet a stellarator can overcome some of your objections if it works - besides 24/7 operation it is highly modular allowing sections to be pre-built so replacement sections can rapidly and easily be installed. Once the field dynamics/magnets are well understood mass production is very possible. So economies of scale are also doable unlike a tokamak. This is a fusion device only now possible because of computer advancements so past failures have little bearing on this current approach; again, very different than all other designs.

Remember, today we have fantastically superior computers and thanks to the false starts, screw ups and determined attempts to fix these issues major advances have been achieved in fusion plasma understanding.

Yes, Tokamaks, even if they work, can never run 24/7 and it is beyond me why they decided to build ITER. Yes, if it ever gets built, it is a useful test bed for high neutron flux rates and might achieve laboratory break even (no real net power and likely a loss when all is said and done.) Worth the cost? Not likely but we build many things of no real value that cost far more.

Remember, fission plants in the US and Europe do not make a profit (cost of power exceeds what is charged) and that even ignores waste fuel handling/storage costs which will be paid by the taxpayers; and currently as an add on to the rate payer's bill for temp storage. We tolerate this because fission was considered worth the extra cost due to it being vital to our future and defense.

Yes, fusion is difficult and may not be doable for some time but if we do not try, exactly when will it ever be available? The issue isn't failure - the issue is one of foresight.

Re: Real power fusion

Posted: Tue Mar 29, 2016 9:07 pm
by Richard Hull
To even be called a power reactor the first criteria is........Is the thing over unity? Only if it is over unity, do we ask how long can it run.

A fusor can run 24/7 and be doing fusion. Sure a stellatrator can run 24/7. It is a glow machine too, only with magnets. Can it glow over unity and still run for a week or more at full over unity and then.... how much over unity...(COP?)

The stellarator was the very first attempt at fusion energy in the early 50's under Project Sherwood A few were built and abandoned. These things like cold fusion and new energy rise from the dead when we tire of what is currently the "darling" and found to be not working. Will mirror machines be next to make a comeback?

Retooling dead ends seems to work for the fusion community.

Richard Hull

Re: Real power fusion

Posted: Wed Mar 30, 2016 5:45 pm
by Dennis P Brown
Richard, your points are well made and while amazing progress in tokamaks were made in the 90's and some units produced fusion that was "called" break even (and certainly wasn't but was close), none-the-less holding a burning plasma for a few seconds was impressive.

Again, stellarators of today can no more be compared to the 1950 - 70 units as 1940 jet's can be compared to today's jets.

Besides the revolutionary development of a divertor* the advancement of super computers to design and optimize the magnets for these devices is a significant breakthrough. Add to that computer aided design and manufacture of these critical parts (not possible as recent as the 80's) and stellarators have made a huge advancement.

To see this look at the performance of the Japanese stellarator (LHD):

That device holds a plasma stable that is within two orders of magnitude of ignition for many hours (while being heated with 10 MW of neutral beam energy.) The performance of this machine is in many ways superior to the best tokamaks (see the graph in the link for the LHD.) The W-7X is an up grade to the Japanese system. Of course, it will be a few years before the W-7X will be run to and then past the LHD levels. But I have little doubt they will demonstrate that a prototype fusion reactor can be built (would be about 3 - 5 times W-7X size/volume and need tritium leading to ignition and stable burn for many hours (hence massive shielding which will increase difficulty to build such a unit to a level that is very high requiring a major advancement in material science and applied engineering (but not physics.)

So, bottom line is you are basically correct that wall power is good ways out but frankly, fusion power (experimental) is very achievable.

Can a stellarator reach ignition? Looks like it can if we have the will to build it.

*Talk about something that would have been obvious to any high vacuum radio tube worker in the 60's but that which physicist didn't realize until the 90's. And this missing element in any fusion device was the main cause of plasma instability. The divertor has been one of the reasons current performance of tokamaks has advanced to near break even; but that is another story!