Alan B. Pearce rl.ac.uk> writes: > I don't have any references to documents on this, but may find some time to > try and track some down. Why is it that most such articles omit the fact that everyone has noticed the problems they hint at a long time ago and is looking for solutions where there are solutions (pun), i.e. not on land: algae and other water-related biomass. They even have plans to feed these algae with CO2 from power plants. Meanwhile Brazil is the country with the largest use of ethanol for running cars, and yet there is no mention of it in most 'studies'. Also Brazilians are not complaining (much) about this - at least not more than Europeans who pay extortion prices for gas. Lucky omission ? A short search on ethanol algae yields interesting results. Also algae (and any other kind of biomass) can be converted into coal-like fuel using solar energy (relatively high temperature anaerobic carbonification/dry distillation). In the process combustible gases are produced which can even be used to run a generator (see wood gas generator engines). Part of those gases are alcohols and terpenes, which can be used as fuels as is. This is the essence of running wood gas generator powered engines. Some fun reading: http://etd.gatech.edu/theses/submitted/etd-08182004-145924/unrestricted /zhang_ling_200412_mast.pdf http://ethanolproducer.com/article.jsp?article_id=2464 In general I can see that most articles that imply ethanol and biomass as 'net energy negative' and otherwise not workable are biased somehow towards land based, specific ways to create and process said biomass (usually in ways that are extensions of the current fuel processing and distribution infrastructure - conveniently disregarding the fact that that infrastrutcure is regarded as a wasteful and inefficient one by many). Meanwhile humanity has relied on wood and other biomass burning for heat and cooking for 6000 years at least (more likely 30,000 years). Charcal has been known since at least the iron age (charcoal is the pyrolysis product - a form of fast, wasteful, low tech carbonification - of wood). I'd say that it's a question of cutting the b**s**t and facing the historical facts and working hard engineering and chemistry-wise towards results. Also delete the idea of 'net energy negative' permanently. I feel sick every time I read it, no matter where. I am a member of a species that ekes out an existence from the unevenness of the energy flow deposed by the sun onto this planet, on its way towards becoming an increase in entropy. There is no way to make that flow 'positive', either net or gross. Therefore 'net energy negative' is an attribute that goes for ALL uses of energy, and that includes breathing. Funny that for all the times I have read the words 'net energy negative' I cannot remember one single instance where someone said 'net enegry positive'. Peter P. -- http://www.piclist.com PIC/SX FAQ & list archive View/change your membership options at http://mailman.mit.edu/mailman/listinfo/piclist