In our case we were using surplus photovoltaic cells to power the thing. Even so it is a slow almost unusable process for modern power requirements. Definitly incapable of providing sufficient gas to power anything in other than periodic use. Currently am working on a direct ethanol fuel cell stack. Less efficient but none of the problems. >From what I have seen there are several designs or portions out there that are really or were really quite interesting. The problem is everyone played hydrogen lemming and jumped off the cliff (and for some reason every thing else was instantly old garbage technology). /sarcasm mode ON 'For "some" reason that turned out to be not very feasible' /sarcasm mode OFF That's the case of the salesmen selling vapourware (literally) to everyone. It would be interesting to see the cycle cost of the various aluminium based designs. No matter how great the promise that right now is going to govern what gets built. For example the alum air cell has/had a problem with corrosion/erosion. Puts out a butt load of power though. Maybe as a super long life battery replacement it would find a niche. Right now the best bang for the buck is still good ole lead acid batteries. Dave -----Original Message----- From: piclist-bounces@mit.edu [mailto:piclist-bounces@mit.edu]On Behalf Of Stephen R Phillips --- Dave King wrote: > Do I detect some scepticism about running a engine on something > that produces oh say 2 litres of hydrogen an hour?? > > Lets see I have a 5 liter engine in the truck, so as long as I > keep it under 1 rpm ever two hours I have plenty of fuel.... > Wouldn't it be more practical to use the old Aluminum air fuel cell instead of this? It's kind of like running up some stairs so you can get more speed to jump. Although hydrogen is an excellent fuel, the Carnot efficiency of the system lower than that of direct energy conversion. It's rather wasteful to be simple. Of course the big issue is controlling the Al O2 reaction and the other issue of using sodium hydroxide. To my knowledge these can be over come, I suspect it was popularized by the fact you couldn't put it in an Internal combustion engine. Detroit hates change you know, so much so it's willing to do REALLY arrogant things. I believe with a bit of examination the energy density of a Al O2 cell will be higher than that of a system generating hydrogen for a different kind of fuel cell. Seems a bit like the corn to alcohol idea. More political than practical. Call me pessimistic but it doesn't seem all that practical. All it will do is give Detroit an excuse to continue making messy machines. I'm not an environmentalist, I just despise the blatant nauseating behavior of people who lack any vision or care not one whit for anyone else. ____________________________________________________________________________ ________Luggage? GPS? Comic books? Check out fitting gifts for grads at Yahoo! Search http://search.yahoo.com/search?fr=oni_on_mail&p=graduation+gifts&cs=bz -- http://www.piclist.com PIC/SX FAQ & list archive View/change your membership options at http://mailman.mit.edu/mailman/listinfo/piclist -- http://www.piclist.com PIC/SX FAQ & list archive View/change your membership options at http://mailman.mit.edu/mailman/listinfo/piclist