As before, they are claiming to have got more energy out of a laser-pellet fusion reaction than they put in.
As before, they are claiming to have got more energy out of a laser-pellet fusion reaction than they put in.
So long as you don't count all the other energy they use.
“or surely enough this old donkey might die." while he was living comfortably with a good salary...
“or surely enough this old donkey might die." while he was living comfortably with a good salary...
If the donkey dies after nine years, and Tamerlane gets a new donkey, the ten years starts all over again - and the salary continues.
(As we all know, it isn't ten years, but forty - always starting as soon as the next machine is built)
So long as you don't count all the other energy they use.
That is the point Krivit makes. He says the plasma fusion people are misrepresenting the energy gain by not including input power. I don't think so. It is clear to me what the plasma people are saying. But, perhaps, that is because I am used to their scientific presentations. Perhaps they could explain it more clearly. I guess they might even be deliberately obfuscating, which is what Krivit says.
Anyway, we can't talk. Many cold fusion experiments take a great deal of input power. With electrochemical ones, sometimes output is only a few percent above input. As discussed here, many skeptics claim that input power is noise and cannot measured with precision, so the results might be wrong. That is nonsense. On the other hand, the high input power precludes any possibility of making this into a practical source of energy.
For that matter, if you include the power going into the calorimeter pumps, the mass spectrometer and other instruments, overall a cold fusion experiment consumes far more than it produces.
The point that Krivit makes is about the way the information is presented for mass public consumption. We obsessive nerds can’t be fooled as easily as the general public in complex technical matters. Anyway, I think that in the CF case including the instrumentation, we are still way better in ratio of total energy in vs total energy out.
Anyway, I think that in the CF case including the instrumentation, we are still way better in ratio of total energy in vs total energy out.
By a factor of several thousand.
As I understand it, hot fusion view COP >= 2 as success measured at the experiment boundary - on the grounds that with 100% efficient lasers etc and power recovery that would mean useful power excess. It is not contentious, and well documented, that fusion happens at some level in these experiments, so COP > 1 is not news.
Whereas LENR experiments tend to think that COP > 1 proves that LENR exists, and is interesting.
There is then the question of integrity of measurements. And of practicality.
For all of the hot fusion methods there are significant losses on input side and also (in practice) on output side. In theory near-perfect electricity generation from alpha particle K.E. is possible for reactions that generate only alphas. In practice this is not easy at all. Thermalising all output and using a generator seems still the only practical method - and delivers 40% efficiency. It is worth noting that for LENR systems there will be a similar issue (or worse if heat is at lower temperature).
On the input side lasers currently used for research are very inefficient. In principle high power lasers can be made quite efficient. maybe 50%???
So under optimistic assumptions the output/input ratio needed is 10X (COP = 11) for 50% of the output power to be available externally. That is a reasonable metric since with lower availability the cost of the generating and cooling equipment goes up, and therefore capital cost, per MW generated.
The current results are COP=3.25
For integrity of these NIF measurements of power in and out I do not know. I have not seen them accurately written up.
THH
