There may be a good reason for a limitation of 6 hours for self-sustaining mode. It would be far better if the reaction slowly damped out with time than for someone to have to vent the hydrogen or add much additional input water to achieve that result. You would thus be able to turn off the power source to kill the output.
I think that I would personally prefer a design that lost power output quickly after the drive is removed. I agree with your assessment that it was wise to stop the reaction after 4 hours. The data appears to support the contention that the output was tailing off slowly. Future devices will no doubt have a much higher ratio of output to input. This is going to be driven by the cost of input electrical power, which is significant. I have not seen any absolute reason that the 6 to 1 ratio is required. In my opinion, the self-sustaining mode is more of a show than practical. I can see little reason to use this technique in the final product. The average input power is what really counts. I am hoping that the test today will be well documented and we have access to the data. Am I dreaming? Dave -----Original Message----- From: Jed Rothwell <[email protected]> To: vortex-l <[email protected]> Sent: Fri, Oct 28, 2011 10:21 am Subject: [Vo]:Rossi: self-sustaining limit is around six hours Earlier I said that I do not know the limits of self-sustaining operation and it might go on in that mode indefinitely. Recently, Rossi said that the limit for this particular machine is around six hours. I do not recall where he said that but I am sure he did. Some people have said he should have left the October 6 test run in self-sustaining mode for longer than four hours. That would have been nice, but apparently it was close to limit, and it would need to go back to a controlled mode. It is unclear how long the controlled phase is needed before input power can be turned off again. Rossi often makes dubious statements about business or nuclear theory, but as far as I know his assertions about the engineering aspects of his devices have all been accurate. I have no reason to doubt this. This is no indication that the technology is fundamentally limited to a six-hour duty cycle. Arata's cells have stayed warm much longer than this. Granted they are Pd-D which might be very different from Ni-H. There is absolutely no indication that the current ratio of 1 W input to 6 W output for most cells is caused by fundamental performance limitations or physics. As I said, this is a lot like saying that railroad locomotives will never go faster than 18 km/h because that's how fast the first one went in 1808. If the 1 MW reactor is run in self-sustaining mode for several hours that would certainly be a good test. >From a technological point of view, there is no advantage to having cells go >into fully self-sustaining mode. Having a small amount of power to control the >cell is just as good as having no power at all. The overhead equipment cost of >generating control current with thermoelectric devices will be trivial, and >the dollar cost for the energy will be zero. I am sure the control current >will ultimately be much smaller than the overall output. - Jed
