Archived posting to the Leica Users Group, 2006/01/30
[Author Prev] [Author Next] [Thread Prev] [Thread Next] [Author Index] [Topic Index] [Home] [Search]Bill, Ask them: http://www.ballard.com/ Joe -----Original Message----- From: lug-bounces+jcyleung8=shaw.ca@leica-users.org [mailto:lug-bounces+jcyleung8=shaw.ca@leica-users.org]On Behalf Of Mattheis, William G CIV Sent: Monday, January 30, 2006 10:07 AM To: lug@leica-users.org Subject: [Leica] RE: LUG Digest, Vol 31, Issue 218 Re: On Jan 29, 2006, at 6:31 PM, Dennis Painter wrote: > Economically viable energy sources may be here sooner than Detroit > thinks. > http://world.honda.com/FuelCell/ > I often wonder where we will obtain the hydrogen required to power a fuel cell. The amount of energy in the universe is fixed. We can only convert it from one form to another. What will we convert to hydrogen? Water via electrolysis seems to be a good answer, but that requires the input of substantial amout of electrical power into the conversion process - - none of which are 100% efficient (neither is the operation of a fuel cell). So we will lose energy in the hydrogen generation process, and we wiil lose more in the conversion of hydrogen and oxyen to water and electricity in the fuel cell - - very clean at the tail pipe, but a little short on efficiency with two losses to consider. We can have a very clean "system" if we convert sunlight to generate hydrogen via hydrolysis to power the fuel cell, but solar cells require lots of space, are extremely expensive and extremely inefficient - - especially on cloudy days. Oh, and you need lots of water for local generatio! n. So, while Phoenix, AZ would be an ideal locale to power solar cells, water may be more scarce that oil as a source of power for cars. Then there is the issue of the energy that must be expended just to bottle (under very high pressures) the hydrogen gas generated - - opps, there goes some more energy expended. Then, of course, we have to compressing air to collect and bottle the oxygen needed by a fuel cell. That will also require significant amounts of energy to power - - where will that power come from?? Oh, last best number I heard for solar cell conversion efficiency was about 18%, and that is in the latest state of the art stuff. I'd like to see the math that suggests that fuel cells are/can be cost competitive with other sources in the near (5 to 10 years) term. I am not trying to rain on anyone's parade, but while I can see the fuel cell as one means of reducing car generated pollutants, it will not reduce our overall use of energy - - just change the form in which we use it. Of course, if we can find a way to do a massive amount of hydrogen generation other than the two viable (sort of) processes I am aware of (hydrolysis and H+ ion stripping from existing hydrocarbons - - there is that oil and natural gas thing again), then we will have a very clean AND EFFICIENT way to do motor transportation. My guess is that we could actually save more oil and reduce pollution faster if we just did the work required to make internal combustion engines a lot more efficient. That just requires better heat management technologies like ceramic or ceramic coated combustion chambers/exhaust management systems. But then, that seems awfully hard when we could just replace piston driven internal combustion engines with turbines that (1) run on most anything that will burn, (2) do so with a lot fewer parts, (3) have very few repairs, (4) are more efficient, and have (5) high operating tempertures that help with exhaust issues (particularly unburned hydrocarbons). Chrysler prototyped such a car in the late 1950s/early 1960s (ran 100 test cars around the US pretty successfully I believe - - except for some exhaust heat problems like scorched paint on tailgating cars I think) - - so it can be done. Plus, the US Navy has clearly demonstrated that jet turbine power ships can be higher effe! ctive and efficient, and future improvements using a turbine to power an electric drive system are on their way. Gas turbines are also great recyclers. They will burn anything from used peanut oil to fingernail polish. They will burn waste solvents, alcohol made from excess grain crops, used oil, l I guess the path we take depends on what we are trying to achieve, "save oil" for the future, or have a cleaner environment by reducing the amount of hydrocarbons we burn. The bottom line is that there is no free lunch. There is no such thing as "free energy." We have to do "work" whether we are freeing energy from sources where it is "latent" such as oil, coal, hydorgen, etc., or converting it from one form, say sunlight, to another, like electricity stored in a battery. And, as far I know, that work, i.e., every conversion process I am aware of, has issues related to efficiency, environmental impacts or other costs to society. Of course, if we could just solve the problem of containing a fusion reaction that we have spent zillions of dollars researching we will have endless, non-poluting energy. See, we have known the answer for a very long time, we just haven't solved the technical problems yet. bill _______________________________________________ Leica Users Group. See http://leica-users.org/mailman/listinfo/lug for more information