tag:blogger.com,1999:blog-19508699.post115874317925872713..comments2024-03-13T18:55:49.391+00:00Comments on Energy Balance: Bioethanol - The Math.Professor Chris Rhodeshttp://www.blogger.com/profile/12060542089215379056noreply@blogger.comBlogger3125tag:blogger.com,1999:blog-19508699.post-1160121281736354772006-10-06T08:54:00.000+01:002006-10-06T08:54:00.000+01:00Hi,you make a good point, and one which I addresse...Hi,<BR/>you make a good point, and one which I addressed in the posting immediately following ("Biofuels - a Comparison of Practicality.") In fact, at a biodiesel yield of 2 tonnes per hectare, the math is even worse!<BR/><BR/>You would need about twice the land area to grow a biodiesel crop as is required to produce enough bioethanol to match the energy output of 54 million tonnes of oil. i.e. around four times the area of arable land there is in the U.K. There are crops e.g. palm oil that give a greater yield (about twice) so on the basis of acreage they could just about match the yield from bioethanol (but still need twice the arable area of the U.K. to grow the sugar crop to make it!). Then there are "super" crops which if grown in the best soil can yield about twice that again (around 8 tonnes per hectare), but this is the agricultural equivalent of "going downhill with a following wind!"<BR/><BR/>However, this would require "only" about the entire area of national arable land, and so using such "super-crops", and not growing any food at all, but turning our agriculture entirely over to their production, we could conceivably run our current fleet of cars,lorries and planes on biodiesel!<BR/><BR/>What is worrying is that the rain forest is being chopped down (slashed-and-burnt) to grow these crops (not in the U.K., obviously - we destroyed our forests centuries ago for shipbuilding and to make charcoal for smelting iron!), therefore losing much of any real advantage, and contributing to further environmental catastrophe, since the forests themselves become major emitters of CO2 when maltreated in this way!Professor Chris Rhodeshttps://www.blogger.com/profile/12060542089215379056noreply@blogger.comtag:blogger.com,1999:blog-19508699.post-1159340508076929362006-09-27T08:01:00.000+01:002006-09-27T08:01:00.000+01:00Hi mcrab,no "snippyness" taken at all! My point in...Hi mcrab,<BR/><BR/>no "snippyness" taken at all! My point in part is simply to get people aware of the sheer "scale" of the problem facing us, in terms of just how much fossil fuel we would need to replace at current levels. Certainly, my overall intention is, as you say, to try and arrive at some practical solutions. I am also coming around to the idea that there is no "one fix", and probably there will be more emphasis on "micro-generation". So, energy might be made locally according to whatever particular resource there is, e.g. a river. Interstingly, Her Majesty The Queen has had a couple of (micro) hydroelectric turbines installed in the river Thames below Windsor Castle, so she is leading the way here! I am sure that there will be an ultimate "mix" of technologies. I have read your "link" about the PHEV and I must say it looks very promising. However, I wonder whether there is sufficient infrastructure to provide the required electron-storage capacity ('batteries' if you will), on such a grand scale (factories and raw materials, e.g. cadmium is quite a scarce mineral). I don't know how many cars there are in the world, or in the U.S. I believe (from memory) there are about 20 million of them in the U.K., for a population of about 60 million. But, I think that this may be the limiting factor in the inauguration of electric vehicles on the grand scale. What do you think?<BR/>I am also fed-up with the doom and gloom, and I feel in a way fairly optimistic. Sure, we are going to have to live differently - in some way, but I don't think there will be an overnight crash. Probably the changes will come more gradually, and they will be ushered-in by economic drivers. So, things in general will become more expensive. That is bad news for those who carry heavy debts. I saw something on the news this morning that the U.K. is the heavist population of debtors in Europe! So, if a lot of people in this situation lost their job, for instance - and companies might go to the wall in times of economic recession - they would join the ranks of the inevitably growing poor.<BR/>It all needs some planning. At present the West seems to be "in denial". Maybe there should be a 12 step programme for the fiscally intemperate!<BR/><BR/>Please keep popping-in!<BR/><BR/>Kind regards,<BR/><BR/>Chris.Professor Chris Rhodeshttps://www.blogger.com/profile/12060542089215379056noreply@blogger.comtag:blogger.com,1999:blog-19508699.post-1158921009134156042006-09-22T11:30:00.000+01:002006-09-22T11:30:00.000+01:00Hi,thanks, and I will look into this further!I qui...Hi,<BR/><BR/>thanks, and I will look into this further!<BR/><BR/>I quite agree, I don't want to return to the stone-age either, but<BR/>it annoys me to see fuel being squandered on kiddie-runs in fleets of SUV's. We walk! Sure: it is a real vote-loser to suggest "frugality", and no government will, until that "last ditch" arrives. That is the tipping-point where our technology has failed us!<BR/><BR/>However, I feel that some other kind of fuel-cut - if that can be <BR/>done (you mention 80%) - would take us a long way toward a sustainable scenario, when biofuels (ethanol seems best in terms of tonnage of fuel per hectare) might make a significant contribution to the final "mix".<BR/><BR/>Overall, using "fuel" in the form of "electrons" seems to be a lot <BR/>more practical than hydrogen. Hydrogen really loses out in the well-to-wheel stage, i.e. it is fairly inefficient to make (in practice anyway). I gather that, as is the problrem with storing electricity on a large scale made from solar-power, implementing sufficient "battery technology" is at issue.<BR/><BR/>But, either way, the situation needs to be taken seriously, and if <BR/>our world governments don't do so... we are headed for, probably not the<BR/>stone-age immediately, but say the rural-economy of 1850's England (or its U.S. "pioneer" equivalent)!<BR/><BR/>It's good to get some decent feedback - much appreciated!<BR/><BR/>Chris.Professor Chris Rhodeshttps://www.blogger.com/profile/12060542089215379056noreply@blogger.com