To: Sword who wrote (221 ) 8/17/2001 2:23:04 AM From: Maurice Winn Respond to of 455 Sword, thanks for that information and comment. I have two problems with the fuel cell microturbine hybrid. One is that I am very unconvinced to the extent that I think it's a load of nonsense that we need to sequester carbon dioxide to avoid air temperature rises. Perhaps we are able to raise air temperatures by burning a great deal of fossil hydrocarbons. I doubt it. Even if we are able to raise the temperatures, by increasing the CO2 content, I would not be surprised if that is a good thing rather than a bad thing. I think increased temperatures and increased carbon dioxide could be good rather than bad because the earth's natural inclination seems to be an ice age. If we think rising sea levels are bad, wait until the high latitude people have a couple of kilometres of ice and snow on top of their farms and cities when an ice age is underway. Also, plants like to eat carbon dioxide. That's their food. All the fossil hydrocarbons used to be in the ecosphere so I'm unconvinced that it would be any bad thing for them to be alive again, joining the great DNA rat race. I suspect that ice ages became common-place as the carbon dioxide was stripped from the atmosphere and deposited under the oceans, and in oil, gas, coal and limestone. Without the natural warming provided by that fecund ecosphere, the thinner atmosphere let us cool off into ice ages. So I would not want to spend my money on solving a problem which doesn't exist, which seems, to a large extent, the aim of the hybrid system. Fuel cells seem largely aimed at carbon dioxide emissions control but also at other pollutants. Since a turbine avoids the other pollutants, to a very great extent, the advantage of a fuel cell added is to improve thermal efficiency. Which brings me to my other problem with fuel cells; the capital cost. I haven't studied this, so maybe they are cheap or can be very cheap. I don't think that's the case. So, it becomes a matter of whether the extra fuel efficiency of adding a fuel cell justifies the extra cost, weight, space and problems of adding a fuel cell to a turbine-powered vehicle. I'm especially interested in the transport solutions but do appreciate that distributed electricity and space heating might be hugely valuable. For fixed applications, the extra cost of a fuel cell would need to be justified by the thermal gains from 25% to 75%, which seems a very big gain and I expect the extra cost could be justified. Weight, space and maintenance are less problematic in fixed installations than mobile. How much per kilowatt do fuel cells cost? Are they big? Do they weigh a lot? Thinking out loud, Mqurice