Wednesday, January 30, 2008

Hydrogen Powered Ship.

Iceland is about to launch its first hydrogen-powered ship ... well, at least the lights on it are powered by hydrogen. Of all nations, Iceland is probably the best provided-for in terms of sustainable energy, since it sits on the north Atlantic Ridge, and can draw ample geothermal energy from the molten lava that flows underneath it. Natural demonstrations of this source of power are the geysers, which respond to steam-pressure in rock-formations by erupting spectacularly at regular intervals. The ship is called the "Elding" which is the Icelandic word for "Lightning" and is set to be converted as the world's first hydrogen-powered sea-vessel. In the first instance, it is just the lights that will run on hydrogen "fuel", but it is taken as a gesture of commitment to Iceland's intentions to transform the nation to a hydrogen economy.

Presently, Iceland earns 70% of its (GDP) money from fishing, using a fleet that is fueled almost entirely by imported oil. If it could play its favourable geological hand to convert geothermal energy into hydrogen by electrolysing water, that would confer security of fuel-supply to the nation. However, I am not entirely sure how the hydrogen might be used overall - yes, fuel cells are the obvious means, or it could simply be burned in internal combustion engines. However, the latter loses the advantage usually claimed for hydrogen, that PEM fuel cells give about two or three times the efficiency in terms of well-to-miles compared with hydrocarbon fuels, calorie for calorie. Whether the technology can be adapted for ships remains to be seen, and it is claimed that about one tonne of hydrogen will need to be carried for a 4 - 5 day voyage.

The hydrogen-powered lights will allow tourists a closer look at the whales, since the ship can be made soundless. Normally, the noise of a ship's engines frightens the whales off, but by cutting the engines at the point of view, and eliminating the engine that is normally used to run the lights, which will instead be powered by a hydrogen/fuel cell, the mammals should not be alarmed, and will probably find the alien vessel a curiosity. The cost of a trip on the Elding is 43 Euros (about 30 quid or sixty bucks). The trippers should also be able to hear the whales swim and blow water more clearly without the rumble of an auxiliary engine in the bowels of the ship.

Iceland, with its population of 300,000, has announced an intention to convert its entire economy to hydrogen by 2050, which is a considerable undertaking, although nothing compared to switching-over a country the size of the UK, with 60 million people in it. Two-thirds of the world's electricity is made from non-renewable, mainly fossil, resources such as coal and gas, while two-thirds of the electricity used in Iceland is made from renewable resources, since it is well-supplied by rivers and waterfalls and the geothermal energy I have already alluded to.

There is a hydrogen filling station in Reykjavik, originally intended to fuel three buses, but was opened to the public in November of 2007, coinciding with the import of 10 specially adapted Toyota Priuses that run on hydrogen. NB, they BURN hydrogen in internal combustion (IC) engines instead of petrol, and are not fuel cell driven vehicles. The station will also provide hydrogen to run the ship, presumably also with an IC engine, rather than an array of fuel cells? Still, if the Icelanders can get the hydrogen effectively for nothing, why not use it thus, even if the efficiency is reduced from the PEM limit to that of the thermodynamic Carnot Cycle.

The chief of Icelandic New Energy, Jon Bjorn Skulason, predicts that by 2030 - 2035 most of Iceland's vehicles will run on hydrogen fuel. Personally, I am doubtful. There are many problems to be solved attendant to using hydrogen as a "fuel": making it in the first place - in Reykjavik by in situ electrolysis of water at the filling station; and storing it in sufficient quantities in vehicles that they don't need to refuel every 10 miles or so. For example, one tonne of hydrogen gas for the Elding, at atmospheric pressure would occupy 12,500 m^3, but compressed at a pressure of 5,000 psi (pounds on the square inch), this is reduced to 12,500 x 15/5,000 = 37.5 m^3. That's about the size of a room in an average terrace house. In liquid form (at -253 degrees C) one tonne of hydrogen would occupy a little more than one third of that, or 13.7 m^3, but it takes about 30 - 40% of the energy the gas can deliver to liquefy it. In comparison, high compression consumes around 20% of the energy "stored" in the hydrogen itself.

On a world scale, implementing the engineering to make and handle hydrogen would be staggering and is unlikely to be done within 10 years, by when world oil supplies will have begun to dwindle substantially. Hydrogen is not going to come in time to save the world from the impending energy-crunch, particularly for transportation fuel, but for its own needs, maybe Iceland will do it. We shall see.


Related Reading.
http://planetark.org/avantgo/dailynewsstory.cfm?newsid=46589

Monday, January 28, 2008

Shell Boss Gives Oil 7 Years.

The CEO of Royal Dutch Shell, Jeroen van der Veer, stated in an e.mail to his staff last week: "Shell estimates that after 2015 supplies of easy-to-access oil and gas will no longer keep up with demand." Now this has put the odd cat among the proverbial prey, coming from such a major as Shell, but it concurs with the most optimistic reckoning by Norway's Statoil company analysts who predicted that the peak in world oil production would happen during the period 2010 - 2015. That the rising demand for oil will outstrip its supply, in the face of a geologically culpable decline in output, according to the Hubbert Peak theory, is no surprise, and indeed the editor of the Petroleum Review, Chris Skrebowski, recently predicted that the global production peak will come in 2011 - 2012. If anything, we should feel reassured by Mr van der Veer's message.

The rest of the e.mail addresses other issues and timescales regarding future energy provision. It advances the proposition: "by 2100, the world's energy system will be radically different from today's." That, no one in his right mind can really contradict, but then we are promised: "Renewable energy like solar, wind, hydroelectricity and biofuels will make up a large share of the energy mix, and nuclear energy too will have a place." If, by 2100, much of the Earth's oil and gas are gone or basically unextractable on their present scale, the whole fabric of civilization will change and we will need alternatives to fill the huge and gaping energy-hole that their dearth will leave behind. However, it is really anyone's guess exactly how much of each might be provided, and I doubt that a match in magnitude is possible. Therefore, the energy-mix of 2100 will be characterised mostly by its smaller overall quantity, and the lack of available transportation by then.

The fall in transportation will inevitably result in less energy being required to run the 2100 world, since we will be dependent on local production and economies (villages), and far less so on global business if carriage of goods from cheaper points of production (the developing or "Southern" nations) to the West is greatly restricted by a lack of fuel to put into ships and planes to bring them all over in. However, even if we concede that by 2100 the world will have sorted itself out and there may even be fusion power and hydrogen fuelled transport to hold par with current levels, nonetheless Mr van der Veer stresses that: "Indeed, the distant future looks bright, but getting there will be an adventure." Now that is euphemistically put, I must say.

Shell is of the opinion that the world will take one of two routes: "Scramble" or "Blueprints". Scramble is a kind of "chocks-away" heroic race through a mountainous desert, which like an off-road rally promises excitement and fierce competition, but many will crash along the way. In literal terms, this is the kind of ongoing vista where all nations go to any lengths to grab whatever oil and gas (and uranium?) is left in the ground for themselves, in a "pull-up-the-ladder" strategy (to coin another quaint English saying). Blueprints is a more designed ride on a road that is still under construction (I like the analogy with the putative renewables-based energy infrastructure here). The consequences, as Mr van der Veer says, are: "Whether we arrive safely at our destination depends on the discipline of the drivers and the ingenuity of all those involved in the construction effort. Technical innovation provides for excitement."

Technical innovation can also provide for smokescreens and red-herrings, e.g. a putative hydrogen economy that exceeds the world resource of recoverable platinum to make enough PEM fuel-cells run it, but which with sufficient "outreach" activities and glamorous publicity lulls the public into a false sense of security that it's O.K. Don't worry about it. We have alternatives. It might just take a few years to get them up and running.

We are in trouble. There is nothing that can match the volume (84 million barrels a day or 30 billion barrels a year) of oil we get through, certainly not within 7 years, as Mr van der Veer implies, or more urgently according to other analysts, beyond which supplies will fall by 2 - 3% every year until in a couple of decades most of the world can forget about relying on oil. When OPEC artificially cut its production of oil by 5% in the early 1970's, the price of oil increased fourfold (400%), and that was simply a matter of politics, i.e. they could easily open up the valves again, and when they did, cheap oil came back onto the markets thus negating incentives to find alternatives to oil. Now the problem is set in the structure of the earth and the limited resource of oil it contains. Falling oil supplies will impact unprecedentedly on the world economy, by restricting both available transportation-fuel and the raw hydrocarbon feedstocks on which most of our industries depend, including those of food production.

If we re-enter the small village, stepping back from the global village, I doubt there will be enough surplus energy from whatever oil, gas, nuclear, coal etc. remain, to later transform the world to the 2100 energy utopia that Shell envisages, whether or not most of us have already crashed along the way there.


Related Reading.
[1] "Shell chief fears oil shortage in seven years." By Carl Mortishead, World Business Editor, The Times. http://business.timesonline.co.uk/tol/business/economics/wef/article3248484.ece
[2] E.mail from Jeroen van der Veer to All Shell Employees: http://www.theoildrum.com/node/3548#more

Wednesday, January 23, 2008

Oil Dearth Agriculture?

It may be coincidence, fate or a shift in world consciousness, but recently, I have noticed a large number of articles written on the subject of how agriculture might fare once cheap oil is no longer in its present abundance. It is often argued that the most practical diet would be vegetarian, for one reason that it takes less land area to grow crops than to provide an equal number of calories from animal husbandry. It is also argued e.g. by the Vegan Society that such a diet is more healthy. However, adopting an entirely vegetarian diet comes with the caveat that deficiencies in certain essential dietary components, e.g. vitamin A, vitamin B12, iron, calcium and fat might be incurred, whereas they are provided by eating at least some meat. Nonetheless, there are many who live well without consuming animal products, and so these should not be considered an absolute daily necessity.

Modern farming depends on fossil resources in a variety of ways. Fertilizers and pesticides depend on gas and oil as raw chemical feedstocks for the industries that make them. Farm machinery is fuelled by oil, and so it is oil that drives the tractors, combine harvesters, and so on, and which enables the ultimate carriage of crops and meat to their end points of use, which for us in the West is mostly supermarkets. To protect the products from spoilage, food items are wrapped in unrelentingly robust packaging (made from oil at that), most of which ends-up on landfill sites, along with about one third of all the food bought in the UK which is thrown away too. The problem of saturating landfill sites is such that most local authorities here have implemented recycling programmes, and while there is periodic concern raised that much of "recycled" waste actually finds its way onto landfill sites too, we are assured that in the Borough of Reading in Berkshire, where I live, the papers, tins and so on, really are used to produce new goods, and this saves resources both of raw materials and energy.

In his book "The Long Emergency", James Kunstler has stressed the vulnerability of urban America to the impending loss of cheap oil. Emplaced along highways, such accommodation settlements are relatively remote from its residents' places of work, and other than living space they offer very little. As the price of oil soars while its supply declines, Kunstler argues that such societies will undergo a steady collapse. Consequently, such personal calamities as businesses failing and jobs being lost are to be expected, while the financial sector roller-coasts up-and-down in perpetuity, thus constituting a protracted crisis that he calls "the long emergency". According to his argument, those living in cities will fare little better, since it is not clear how such densely populous conurbations might be deconvoluted into sustainable local societies. Perhaps they cannot. I believe that it is at least in principle possible to redistribute large populations across entire states, counties or entire nations, but most likely large swathes of people will be drawn out from cities and inner-cities when essentials of fuel and food can no longer be brought in sufficiently from further afield. The latter is not a pretty prospect and I hope that such relocation is not simply left to the prevailing market forces to sort out, as most other things are these days, in a hangover from pseudo-monetarism, discredited though that financial philosophy now is.

If people are no longer able to travel long distances to work (or that those enterprises that employ them have meanwhile gone bust), and neither is it feasible to bring essential goods from afar to supply them, the only practical action is to provide the essential means for living at the local level - hopefully in a planned strategy - and this will inevitably pivot around farming. It is an important consideration then, to decide exactly what crops these farms should grow. If we were to try and live on green vegetables alone we would slowly starve, and it is grains that provide most of the calories we need to fuel our bodies. Wheat, rice, maize, barley, rye, oats, sorghum and millet are prime such examples. We need proteins, carbohydrates, vitamins and minerals, many of which are provided adequately from grains. Winter (not summer) squashes are high in calories, as are parsnips, while carrots, turnips, rutabagas and beets yield somewhat less energy. Beans score well in terms of calories too, and provide the best source of vegetable protein, particularly if they are consumed along with maize and other grains which contain complementary amino acids.

It is also essential to try and do some accounting of the amount of land that would be necessary to support populations at particular levels. Exactly how much land is needed depends on the type of crop, the soil and the prevailing climate of its particular circumstance. Those crops that yield the most in terms of food are not necessarily the most resistant to disease, nor the best that can be grown according to the climate and soil-type for a given location. Changes in weather conditions can have a devastating effect on particular crops too, e.g. onions, which normally are grown sufficiently in the UK to keep us supplied throughout the year, are now predicted to run-out within 6 weeks or so because of the severe flooding last year, which has rotted them in the ground. They will thence need to be imported from New Zealand. QED!!

David Pimental referred to one study of maize production using slash-and-burn farming methods in Mexico, which produced 1,944 kg of maize per hectare - equivalent to 6.9 million kcal of energy. Since we will be far less sedentary in the Oil Dearth Era, it is reasonable to assume that an average hard-working adult might need 5,000 kilocalories per day to keep them going; hence it can be concluded that one hectare of maize can support 4 people. There is around 15 million km^2 (1.5 billion hectares) of arable land on Earth, and so we might naively conclude that this is enough to support 6 billion of us, or close to the present world population. This is however rather more generous than the roughly 3 billion that I predicted it could provide for, in a recent posting, but I did allow that the Earth should support other animal species than just humans and that not all those other species should be only those that live entirely in the service of humans. Roughly one quarter, 65,000 km^2, of the UK mainland is available for growing crops (arable) , and about another half of it for grazing animals (pasture). The rest of the almost 250,000 km^2 is fen-land, forest and so on, not suitable for farming.

Clearly, keeping animals should not impede on arable land if they can all graze on pasture, but that is not of course how modern agriculture works at all, and we feed crops to animals to improve their weight etc. Nonetheless, I think we will still need animals both for food (meat, eggs, milk etc.) and for their muscle-power, e.g. horses and oxen. I do not envisage any immediate return to a society driven purely by human and animal muscle-power, but there will most likely be an increasing agrarian component arising within our efforts to achieve a sustainable scheme for living. Use of GM is proposed to enhance crop yield and help to feed a world population that is predicted to rise from its current 6.5 billion to about 9 billion by 2050. However, by then we will be severely restricted in terms of oil supplies, and the carrying capacity of the planet without present levels of fossil materials (oil and gas) will be considerably reduced from the artificial bubble of plenty we have created with ample such resources.

The worst scenario is a "die-off" which some believe will involve a reduction in the world population to under one billion, through wars over resources and unchecked epidemics of disease. Hence in the absence of plentiful oil and gas supplies, even with GM, we cannot feed everyone, let alone provide the developing nations with a "Western Lifestyle" that even for the West has become untenable. I do not believe that some new brand of technology (e.g. hydrogen) will come to our aid within 10 years, by when world oil supplies will have fallen to perhaps 90 - 95% of current levels and the world economy is reeling in panic. Holding-onto our global consumer lifestyle is a doomed prospect, and we might as well get used to the idea and to that of a return to village-life.


Related Reading.
[1] "Agriculture in a Post-Oil Economy," By Peter Goodchild. http://www.countercurrents.org/goodchild220907.htm
[2] D.Pimental and C.W.Hall eds. "Food and Energy Resources," Academic Press, Orlando, Florida, 1984.
[3] J.H.Kunsler, "The Long Emergency," Atlantic Books, London, 2005.

Monday, January 21, 2008

Permaculture: = permanent oil-dearth culture.

The term "permaculture" is a portmanteau word that may be considered to arise from permanent agriculture or permanent culture. It involves an essential earth-centred philosophy/culture that aims to preserve the environment, living in harmony with our use of its resources, but without causing destruction of habitat on a local or planetary level. This at least, is my interpretation and such principles fit well with a set of actions that do not require more energy than can be sustainably provided to allow them to be done; thus local ecologies and the planetary ecosystem is not stressed beyond breaking point and maintaining life within its clear limits becomes both possible and desirable. As might be expected, whether such an aim can be fulfilled or not depends both acutely and chronically on those methods of agriculture that are adopted to support both collective and individual communities.

I am avoiding the term "peak oil", which has rather lost its impact. Ironically, now that it is spoken of widely in the media, the shock value it had for me certainly, has become blunted. I prefer then the more explicit phrase, "Oil Dearth Era", which offers clearly the premise that a shortage (dearth) of cheap oil is inevitable on passing the maximum output of oil production (peak oil), and that the event will not be a one-off "flash-in-the-pan" but an "era" of considerable length, probably permanent. We could adapt the expected conditions into the phrase, "permanent oil-dearth culture" which also accords to the label permaculture.

The principles of permaculture might be identified as follows:

(1) Work with nature, not against it: use it as a teacher.
(2) Everything in nature "gardens" - for example, deer in a forest cultivate edible shoots by grazing/pruning them back.
(3) Minimum effort for maximum output - perfected, apparently, by a "do-nothing" farmer in Japan.
(4) The problem is the solution - e.g. thistles on grazing land which livestock don't eat, aid the fertility and condition of the soil.
(5) There's no theoretical limit to yield - only the imagination of the designer.
(6) Multiple elements and multiple functions - something as simple as a greenhouse is useful not just for propagating plants: it extends the growing season, collects rain from the roof, collects sunlight etc.

Indeed, the latter principle might be adapted to all buildings, which become and integrated part of the enterprise, feeding back water and energy to promote growth and husbandry. Point (4) reminds me of the "Dymaxion" principle espoused by Buckminster Fuller, which seems to accord with a state of permaculture.

Permaculture can be considered in terms of "zone sectors", which can be identified approximately, according to the relationship between human energy expended and the land itself:

(1) Zone 0 is your house.
(2) Zone I is your garden or immediate external space.
(3) Zone II is orchards or "allotments" as we call them over here.
(4) Zone III is farmland.
(5) Zone IV is rough grazing and woodland.
(6) Zone V is wilderness.

Both permaculture and the dymaxion principles can be thought of as a kind of "intelligent design", which makes the greatest use of human energy, while minimising serfdom and drudgery, as we associate with peasant or feudal labour.

It is debatable how much of our total current energy we will be left with as oil prices rocket sky-high, and there are actual shortages of fuel, which amounts to about one third of all the primary energy used in the U.K. Even if much of overall energy could be maintained e.g. by nuclear power, coal, remaining gas and any other means, a way to substitute for transportation fuel has not been clearly identified, beyond pie-in-the-sky shouts of "hydrogen", solar" and so on, with no mention or consideration of what would be needed to fashion an infrastructure of production, supply and end-use, of sufficient and realistic dimension to do the particular job. I see no clear solution ready to be installed within 10 years, say, by when the Oil Dearth Era will be well and truly with us, and suddenly, relatively immobile populations will amount, who will need to survive by obtaining their necessities within quite near localities. Now, this could be called permaculture, couldn't it?


Related Reading.
[1] New Internationalist, July 2007.
[2] http://en.wikipedia.org/wiki/Permaculture.
[3] http://www.permaculture.org.uk/

Friday, January 18, 2008

Stolen Cats and Platinum Prices.

The price of platinum has just hit $1,561 an ounce, in consequence of fears that the major producers of the metal in South Africa will be unable to keep pace with rising demand for it. Around 40% of "new" platinum, extracted at a rate of close to 150 tonnes annually, is used for jewelry which is about the same as is used to make catalytic converters. It is reckoned that scrapping one million such "cats" would yield 40,000 ounces of platinum (which works out at 40,000 x 31.10 g/Troy ounce = 1.244 tonnes or 1.244 g per cat, as an average). It is thought that the worldwide "scrap-platinum" market might eventually provide 1 million Troy ounces per year, or 31.1 tonnes; meanwhile, those unwilling to wait have resorted to stealing cats, which we can reckon to be worth $62 each. Equivalent to £32, this is not quite a pedigree beast, but since the devices are quite easily stolen from parked cars (if you know where and how) this is now an increasing phenomenon. I thought that, in fact, the amount of platinum in a cat was nearer 5 g, but technology may have improved since then.

In some of my postings about the considerable limitation in the rate at which platinum can be recovered in relation to the amount of it we would need to make fuel cells for vehicles powered by hydrogen, I have assumed there are 600 million "cars" on the highways of the world, but this does in fact err on the side of caution. At the end of 2004, the figure was closer to 500 million cars and 200 million trucks etc. (up from around 40 million vehicles altogether in 1945), and 500 million of that total are fitted with cats. It is less demanding in terms of platinum to make a cat than a fuel cell, since the latter use up to 100 g of platinum per unit, e.g. that employed by Daihatsu.

The US based consulting firm TIAX have concluded that world platinum will not run-out, and certainly if the amount of Pt required in fuel cells falls (as is claimed, to perhaps one third of the amount currently used, and there are far more optimistic claims too of about one sixth), there would be enough of it in existing mine-holdings to make those 680 million fuel cells, but it is a rare metal which is only laboriously wrestled from its ore, usually over a period of about 6 months. 88% of world Pt comes from 2 mines in SA and most of the rest from another mine in the Urals. Enhancing new Pt output will be very difficult if not impossible in any significant amount.

It is highly unlikely that we will give-up all our jewelry and we need the existing cats to keep NOx and other traffic exhaust-emissions within acceptable limits. It is difficult to predict the date of breakthroughs in research and even more so to predict timelines for their commercial development. Notwithstanding, I am looking at a period of about 10 years, by when according to almost all estimates we will be past the point of peak oil production, and oil-supplies worldwide will be down, probably to 90 - 95% of current levels, which is really going to hurt our lifestyle. I do not believe we will have enough platinum to make sufficient fuel cells by then, to offset a decline in oil-powerd internal combustion engines, nor enough hydrogen to fuel them, certainly not from renewable sources.

In this interim of the "Oil Dearth Era", we cannot expect fuel-cells to help us much, and even if we surrendered half the world's new platinum (75 tonnes) plus another 30 tonnes (which would involve taking 24 million vehicles off the road once their cats had been scrapped) from recycled platinum, we could introduce an optimistic 105 x 10^6 g/say 60 g/vehicle = 1.75 million fuel cells per year. If we could do this starting now, in a 10 year period, we could have 17.5 million new "fuel cell" cars, but we would have taken 240 million off the road for their cats. This would leave us with 680 - 240 = 440 oil-powered vehicles left (having scrapped their cats for the Pt they contain, and ignoring those that had been stolen) plus 17.5 million hydrogen-powered cars, making 67%, or two thirds of the current number.

Rising fuel prices and shortages of fuel will force that number down significantly, and in 25 years we would be left with 44 million hydrogen vehicles, but if the cats are scrapped for their Pt, that will require the loss of 600 million oil-powered vehicles, or most of the current number. These sums are for "fun" (not that I find any of this even marginally amusing) and are open to criticism, but I am simply trying to stress the point that the hydrogen economy, if it could be implemented in the face of Oil Dearth will only provide for less than 10% of current levels of transportation, while the shortages of oil expected over that same 25 years and the inexorably rising financial and energy costs of its extraction and processing will force a majority of current vehicles off the roads.

In the immediate future (a period of 10 years, starting now) we can forget about hydrogen; while making diesel from biomass and from algae by so-called second generation processes offers some hope (and does not compromise food production, unlike first generation biofuels, which ultimately must do), probably only 15% of current transport levels can be so maintained. The notion that we can simply change-over almost overnight to hydrogen or to anything else on a scale that will allow us to hang-onto our current measure of energy profligacy is simply wrong. Accordingly, society will begin to relocalise into smaller self-sustaining communities - if people can't move around so easily they will stay where they are, and will need to find a means for living at the local level. Deconstructing populous cities will be the most testing effort, and may prove impossible, but the world needs a clear plan of cooperative transformation not further war and bloodshed over relentlessly depleting resources.


Related Reading.
[1] "Thieves target catalytic converters as platinum prices soar." CBC News. http://www.cbc.ca/canada/montreal/story/2008/01/10/qc-catalyticconverter0110.html?ref=rss.
[2] "Carmakers gear up for the next shortage - platinum." By James Mackintosh and Kevin Morrision. Originally, FT.com. http://www.theminingnews.org/news.cfm?newsID=800.
[3] "Scrap PGM recovery seen booming in '90's - platinum group metals - scrap." An older article. http://findarticles.com/p/articles/mi_m3MKT/is_n192_v97/ai_7992455.
[4] "Significance of fuel cells to the platinum market." http://www.platinummetalsreview.com/dynamic/question/view/11754.
[5] "Car of the future may stall at start." Business Day. http://www.arizonaenergy.org/News%2005/News%20July05/car_of_the_future_may_stall_at_s.htm


Wednesday, January 16, 2008

US gives Alberta a Crude Sting.

New energy legislation disallows any US federal agencies to buy fuel for vehicles that is made from unconventional sources if its life-cycle production of greenhouse gas emissions is not the same, or less than that derived from conventional oil. This is potentially bad news for Canada, since while the Alberta tar-sands are thought to be one of the world's greatest sources of "oil" (greater than is reckoned to exist under Saudi Arabia), it is also one of the dirtiest resources in terms of the CO2 emissions that are incurred in squeezing it from the bitumen which constitutes the "tar". Potentially, then, the tar-sand oil might not be on sale in the US, which I really cannot believe, as pressure and decline begin to step on supplies of conventional crude oil, which are anticipated to peak somewhere between 2010-2015, with the latest estimate by Chris Skrebowski, that it will strike in 2011-2012. I am quite sure that this legislation, only a month old, will be amended as necessary, according to prevailing circumstances as they unfold.

I am increasingly aware that many events are predicted for 2012, and find this slightly alarming since this is the year on which the Mayan calender ends. Now, it may be that this particular means for reckoning time will simply start again at year 1, but there are many who are of the faith that something pretty dramatic is due then: either a global catastrophe or a paradigm shift in human consciousness. Since there is wide denial blanketing the subject of peak oil - not that it is not due, but that we can install some alternative technology e.g. a "Hydrogen economy" in time to save our rears - there may well be a huge shift in human awareness when the stuff begins to run-out and that is that, and the facts, timing and consequences of the event can no longer be concealed.

Meanwhile, the rules are set to apply to all fuels, including biofuels, and presumably that might impact negatively on corn-ethanol, depending on which analysis is taken to be the truth about its production efficiency. World food prices are soaring both in consequence of rising demand, poor crop yields in the past year, and for corn that much of this potential food crop is being commandeered to make ethanol fuel. I am guessing that the same legislation could be applied as a brake to restrict such food-for fuel actions, thus converting precious arable land back to its original and most pressing purpose which is to grow food to feed a rising human population. Without oil and gas (modern mechanised farming and artificial fertilisers and pesticides), even the earth's total allocation of farmland suitable for crop-agriculture could barely support half the current human population of 6.5 billion.

Just how dirty Alberta tar-sand oil is, depends on who is doing the sums. Figures supplied by the Canadian Centre for Energy Information indicate that the emissions from tar-sand fuel are about 8% higher than the mean for all US imports of crude oil, while independent "experts" think the figure is closer to 20%. Pierre Alvarez, President of the Canadian Association of Petroleum Producers, stated that the industry will make the case that a substantial level of CO2 emissions are incurred in shipping oil from the Middle East and from further across the world. Given the reserves they have, the Canadians are hardly going to give in gracefully, and in the limit of conventional oil supplies falling with calamitous consequences on the world economy, I doubt anyone will want them to.

Closer to home (in Europe that is), a fall in production of oil from Norway has been noted, according to figures released by the Norwegian Petroleum Directorate. A total of 237.8 million cubic metres (m^3) of marketable oil equivalents were produced in 2007, which is reduced by 26.2 million m^3 from 2004, the record year (Norwegian peak oil?). However, gas production has increased, and Norway looks to become a gas-nation from the oil-nation it was. Four new fields have begun their production during 2007: Blane, Enoch, Ormen Lange and Snohvit, while three more are due to begin production in 2008: Alvheim, Vilje and Volve. The overall estimates of petroleum resources under the Norwegian Shelf have not been amended particularly and remain at around 13 billion m^3 of oil equivalent.


Related Reading.
[1] "Alberta crude may be too dirty, U.S. law says," Martin Mittelstaedt, "Globe and Mail". http://www.theglobeandmail.com/servlet/story/RTGAM.20080115.woilsands15/BNStory/energy/home
[2] "Norwegian oil production drops - Gas production up," "The Norway Post." http://www.norwaypost.no/cgi-bin/norwaypost/imaker?id=125794

Monday, January 14, 2008

British Thumbs-up to Nuclear.

In fulfillment of our protracted anticipation, the UK government has just released a White Paper which indicates it will go ahead with building "new-nuclear" [1]. The report is lengthly, at 185 pages, as befits such a sensitive matter, and airs arguments from all sides. Not surprisingly, various environmental groups are appalled at the idea, but rarely do they offer sums to support any view that present levels of energy use can be maintained through renewable sources, mainly because they can't. When I began this blog, I hoped to prove that renewables were indeed all we needed, and having been in Russia when the Unit 4 reactor at Chernobyl blew-up on April 26th, 1986 (five days after my birthday as it happens), I also wished to prove we could do without nuclear altogether, on numerous grounds.

I am no longer of either ambition, having since learned about the colossal amounts of energy we do get through as a population of 6.5 billion, mainly in the industrialised nations, and my feeling now is we will need all we can get, from any and every kind of source. The debate over nuclear is not just a question of building "new" reactors, in a programme of proliferation, but replacing the existing generation of reactors which will, bar for one, have reached the end of their ca 40 year projected lifetimes by 2023. One third of existing coal and gas-fired power stations will also need to be closed within this timescale and so just to keep the current number of lights on, will require building a new generation of nuclear and fossil fuelled power plants. Any further substitution of fossil fuel by nuclear will necessitate more new build for nuclear.

Incidentally, I am well aware of the savings in electricity that could be achieved by using energy-efficient light bulbs, which would mean us needing about three less 1 GW power stations, and so energy efficiency should be promoted as well as power generation, ignoring the apparent health hazard from the mercury they contain, as we were warned of by the BBC last week. "If you break an energy efficient bulb indoors, open the window for 15 minutes," the soundbite said, which doesn't sound too serious to me, and I think we should continue to buy them.

It takes around 15 years to put-up a nuclear power station from scratch and so the first one might just be up and running by 2016, which is the date for the first one of the current cohort of nuclear reactors to be mothballed. Nuclear power provides about one fifth of the UK's electricity in total, which constitutes about one fifth of the entire energy used by this nation; hence the total nuclear share of our overall energy is about 4%. An interesting comparison can be drawn with the nearer 36% of total energy that is consumed by the transportation sector, mainly in terms of imported oil.

This brings on a related issue, that of imported nuclear fuel. Nuclear power is often given the credits that it is carbon-free and that it helps to break our reliance on fuel imports, neither of which is entirely true. As the paper notes explicitly, there are huge variations in various estimates of the amount of CO2 generated by a nuclear power station during its lifetime, including fabricating the concrete to construct it, and the uranium fuel, which has been predicted to cause a rise in the amount of overall CO2 as the uranium ore becomes poorer (lower in its uranium content), the uranium enrichment and the fabrication of fuel rods.

As the report noted, separating uranium isotopes by centrifugation rather than by gaseous diffusion is less energy intensive and will hence generate less CO2, and so adjustments in technology will improve the figure overall. There is undoubtedly a considerable CO2 saving incurred in installing nuclear over gas and even more over coal-fired plants, whatever the final figure proves to be, which should help us to met our greenhouse gas emissions targets. On the issue of security of uranium supply, there are geological surveys being carried out to look for uranium supplies indigenous to the UK, but it is thought that imports of uranium are quite stable. The report also alludes to using thorium as a nuclear fuel (our friendly neighbour, Norway has plenty of it) and converting existing stockpiles of enriched uranium and plutonium to nuclear fuel. We have around 51,000 tonnes of uranium and 200 tonnes of plutonium, or something like it, which could keep us going for about 60 years.

Reprocessing is not being considered in the immediate term but instead storage of spent fuel in underground bunkers; neither are fast-breeder reactors part of the initial plan. However, should circumstances so necessitate it, I imagine that the "depleted" uranium could be dug-up again and processed into plutonium in a breeder-reactor programme, where the majority isotope uranium-238 (normally thrown away or made into "depleted uranium" for shells and armaments) is converted into plutonium-239 (by capture of fast-neutrons), which is a fissile nuclear fuel. Reactors that use "mixed-oxide" fuel, i.e. a mixture of uranium oxide and plutonium oxide, are anticipated. If we do end up using thorium, this will also require a breeder programme, in which thorium-232 is converted by capture of slow neutrons, to uranium-233, which is another fissile material.

There does of course remain the inevitable issue of what to do with the nuclear waste finally, but given the energy crunch we are facing in the immediate term, I think nuclear has a valuable place, whatever concerns about radioactive materials and terrorism (should it fall into malicious hands) remain with me, as I suspect they always will. The major energy problem that nuclear does not resolve is, how to keep transportation running? But really nothing can, or not on the present scale of personal transport. At least by maintaining the national grid, electric trains might still be run for essential carriage of goods and services, but much else will fall to the remit of local economies, being far less demanding in well-to-wheels miles.


[1] "A White Paper on Nuclear Power," January 2008, H.M.Government. BERR. www.dti.gov.uk/energy/whitepaper/page39534.html.

Thursday, January 10, 2008

Isobutanol - a Breakthrough in Biofuel production?

A paper has just appeared in the science magazine Nature, which reports that appreciable yields of isobutanol (IB) and other higher chain alcohols (1-butanol, 2-methyl-1-butanol, 3-methyl-1-butanol and 2-phenylethanol), can be produced by fermenting glucose with genetically modified E.coli. Such higher-chain alcohols have a greater energy density than ethanol and are much less prone to absorb water from the atmosphere, being consequently less corrosive toward engine parts. Liquid fuels should be applauded, since they can be handled within largely existing infrastructures and they do not require the fabrication of new engineering on a staggering scale to do this, unlike hydrogen. Since such liquid fuels can be burned in diesel engines, rather than requiring fuel cells for which there is insufficient platinum to provide more than a small percentage of the current number of the 600 million vehicles on the world's roads, this tried and confirmed means is quite adaptable for the purpose.

However, the question of scale remains. The overall reaction for the conversion of glucose to IB may be represented thus:

C6H12O6 --> C4H10O (IB) + 2 CO2 + H2O.

Since the respective molecular weights of C6H12O6 and IB are 180 and 74, if the process were 100% efficient, we might expect a yield of 74/180 = 0.41 g IB/g of glucose. The actual yield is found to be 51%, and so we get 0.41 x .51 = 0.21 g of IB/g of glucose.

The world uses 30 billion barrels of oil each year. Taking the accepted conversion factor of 7.3 barrels per tonne of oil, this amounts to 4.1 x 10^9 tonnes.

There is a difference in the proportion of oil that is used to run transportation and for other purposes, and e.g. the US uses more of it for heating-oil. It is reckoned that 68% of US oil goes for transportation while the value is closer to 72% in Europe (UK). I shall therefore assume 70% for transport as a world average. Hence, 0.70 x 4.1 x 10^9 = 2.87 x 10^9 tonnes of oil are used to underpin world transport per year.

The heat of combustion of IB is 36.0 GJ/tonne (compared with about 30 GJ/tonne for ethanol) and it is reckoned that on an oil equivalent basis, crude oil can be costed-in at 42 GJ/tonne. Therefore we would need to produce (42/33) x 2.87 x 10^9 = 3.65 x 10^9 tonnes of it annually. Since 0.21 g of IB can be made from each g of glucose, we therefore need (1.0/0.21) x 3.65 x 10^9 = 1.74 x 10^10 tonnes of glucose.

If we assume a good yield of 16 tonnes of "sugar" per hectare from beet or cane (corn sugar yields are nowhere near this), we need 1.74 x 10^10/16 = 1.09 x 10^9 hectares of arable land to grow it on, or 1.09 x 10^7 km^2. That's 10.9 million km^2 and should be compared with the total of 14.9 million km^2 there is available over the entire surface of the Earth.

Hence we may deduce that the enterprise would require 10.9/14.9 = 73.0% of all of it. That's three-quarters! Since we still need to grow food for a rising world population and it is reckoned that without oil and gas to make fuels and run modern "industrial" agriculture that 14.9 million km^2 can only support 3 billion people or less than half the world's current population, the idea of using this technology or indeed any other means for turning food crop-land over to crops for biofuels on a large scale just seems crazy.

In pointing out such matters of scale I have been accused of autarky, when suggesting the dearth of land upon which the UK might be self-sufficient to some extent in terms of fuel production, as we are quite a small set of islands. For example, similar reasoning suggests that to produce the IB equivalent of 60 million tonnes of oil that we use each year just for transportation (and another 23 million tonnes is used for heating and as a chemical feedstock for industry) would require 179,000 km^2 of arable land or nearly three times the 65,000 km^2 we have altogether. "Surely you can just import it all from elsewhere," is the general theme, but the sums above show this simply doesn't stack-up on a world scale. It is striking how annoyed some people become when they are presented with hard numbers that fail to support their pet modes of energy salvation; that some technology will snatch us from the jaws of death at the eleventh hour: yet, this seems to me increasingly unlikely.

The US uses one quarter of the world's recovered oil, and so if 68% of that goes for transport, this amounts to: 0.25 x 0.68 x 30 x 10^9 barrels/7.3 barrels/tonne = 698.6 million tonnes oil equivalent. To produce this would need:

(1.0/0.21) x 698.6 x 10^6 x 42/33 = 4.23 x 10^9 tonnes of sugar, grown on: 4.23 x 10^9/16 tonnes/ha = 2.65 x 10^8 ha = 2.65 million km^2 of arable land. This amounts to (2.65/14.9) x 100 = 17.7% of all arable land on earth, or about one sixth of it. For interest, the total area of arable land in the US amounts to about 1.83 million km^2, to take an autarkic view, and so even the US could not be self-sufficient in fuel to any degree using this kind of technology, clever though it is since higher alcohols are usually only produced in minute quantities during fermentation processes.

Interestingly, these higher alcohols are also known as "congeners" and are thought partly responsible for the well known hangover if we drink too much in the way of alcoholic beverages, rather than the ethanol itself. It appears we are due for the mother of all hangovers in consequence of consuming too much energy, and the only cure will be relative abstinence.


Related Reading.
(1) http://nature.com/nature/journal/v451/n7174
(2) "Efficient Biofuel Made From Genetically Modified E.Coli Bacteria." http://www.sciencedaily.com/releases/2008/01/080106202952.htm

Tuesday, January 08, 2008

Printed Solar Panels

Implementing solar (photovoltaic) power (pv) on the large scale is not practicable using conventional solar-cells, or grounds of cost and availability of materials. The main problem is the relatively large quantities of high-grade silicon that would be required, and the only real salvation for this very attractive technology is via thin-film cells, which use perhaps 1/100 th of the amount of semiconducting material that conventional pv does. There has been a significant advance which potentially brings pv into the wider marketplace, and that is due to a Silicon Valley start-up company, called Nanosolar, a name which provides a clue as to their methodology.

Nanosolar have made the advance of printing pv directly onto aluminium foil, rather like the way newspapers are printed, and the company announced that its order books are full from European consumers, and it seems likely that a second factory will open in Germany which is the main buyer for solar power, outstripping conventional provision of pv. Erik Oldekop, who is Nanosolar's representative in Switzerland, said, "We aim to produce the panels for 99 cents (50 p) a Watt, which is comparable to the price of electricity generated from coal. We cannot disclose our exact figures yet as we are a private company but we can bring it down to that level. That is the vision we are aiming at."

The panels that Nanosolar are producing are intended principally for use in large-scale power plants rather that to be installed on the roof at home. The stated aim is to make power stations up to 10 MW in generating capacity, according to Oldekop, but let's face it that is just 1% of the output of a typical coal, gas or nuclear fuelled power station. On the other hand, these solar-power stations could be running from scratch within 9 months as opposed to 10 years or so for coal and 15 years for nuclear power stations. The latter figures make depressing reading when the UK government is prevaricating over whether to install new nuclear or not, and I think that a date of 2023 (i.e. 15 years from now) will just about bring in new nuclear to replace the present by then obsolete generation of nuclear reactors. If we need to expand the nuclear provision significantly on these shores, a huge nuclear construction programme must be begun immediately. I wonder how supplies of gas and coal will hold-up until sufficient nuclear power is installed, or if they will.

If Nanosolar can be installed on a massive scale, that might buy us time and even comprise a significant proportion of the final energy-mix, but can it be done in terms both of resources and engineering? Currently, solar power costs three times as much as electricity made from fossil fuels, but those costs look to rise inexorably, making solar increasingly attractive from an economist's perspective. Jeremy Leggett, CEO of Solar Century, commented that it would be "breathtaking" if the technology proves as effective as the company projects. He said, "This is a revolution. But people are going to be amazed at other developments taking place in solar technologies. We will be thrilled if this technology is as efficient as the company says. It will not change the direction of solar power itself. Spectacular improvements are also being made in other parts of the industry." I don't doubt it, but the limits are resources and installable engineering, and how quickly the latter can be implemented, as is true of all other putative kinds of technology it is tempting to wax lyrical over.

We will hit a fossil resource crunch within 10 - 15 years, and so any alternatives need to be up and running ASAP. Once we begin to run short of energy supplies to maintain existing demand, e.g. for electricity, it is debatable how much there will be left-over to power the implementation of new technologies. If the world had begun this path in earnest 30 years ago, when OPEC artificially hiked-up the price of oil by reducing production by a mere 5% (which caused a 400% rise in oil prices), we would in all probability have alternatives we could switch over to now, and save precious hydrocarbon resources for more useful purposes (i.e. manufacturing processes) rather than wastefully burning them.

The only retrospective solution is to cut our energy use, to leave enough over for these other strategies, but we won't make any such savings except by default or through rising costs of energy. However I try to derive a prognosis, an eventual gearing-down in our energy demand seems inevitable, but that will necessitate most of us adopting quite different lifestyles, which many will perceive as unpalatable.

Related Reading.
"Solar energy "revolution" brings green power closer," By John Vidal, Environment Editor, The Guardian. http://www.guardian.co.uk/environment/2007/dec/29/solarpower.renewableenergy

Thursday, January 03, 2008

Renewables-Based Technology.

The notion of thermodynamics (energy requirements) and kinetics (rate) is implicit in chemical reactions, but the same principles attend all putative strategies to install new technologies to deal with the world's impending energy-crisis, mainly augered-in by cheap oil supplies running inexorably low. The scale of implementing e.g. hydrogen, solar, unconventional oil from tar-sands, wind, wave, biofuels, even nuclear, and so on, is staggering, but is mostly neither realised nor understood.


For example, if PEM (proton exchange membrane) fuel cells are really the answer to running cars (and planes?) without oil-based fuels, the kinetic barrier is the rate at which platinum might be produced for their fabrication. Around 150 tonnes of "new" platinum is extracted annually, which amounts to around 1.5 million vehicles worth, and that is if all of it were turned-over to this purpose, i.e. no jewelry, scientific apparatus or catalytic convertors to keep the existing fleet of oil-powered cars running clean. This should be compared with an approximately 600 million vehicles on the world's roads, and hence in 30 years a mere 7% of that total could be so provided, by when world crude oil supplies will be vastly reduced. (A Hubbert peak analysis suggests to perhaps just 50 -70% of current levels).


How might we produce hydrogen to put into fuel cells anyway? Since most of the world's hydrogen is currently made from natural gas by steam-reforming, this merely places an additional burden of demand on this resource, and so the ideal would be to make H2 from sustainable resources instead. One such suggestion is to ferment sugar into "biohydrogen", and I was recently berated for stressing the point that if the U.K. were to make its hydrogen this way, it would require more than the nation's total arable land to grow the sugar crop.


"Haven't you heard of trade, dummy?" was the general theme. "I thought you Brits were a nation of mariners!" We were, and also a nation of engineers, hence it should not be beyond our wit to fathom the machinations of implementing a hydrogen economy, and probably the sums have already been done in Whitehall, which is why no serious efforts have been made in this regard here, nor anywhere else for that matter.


If my critic is right and we can simply buy all that sugar in from elsewhere, how much arable land would it take to grow enough sugar to run the world's transportation on biohydrogen made from it? Roughly 30% of the Earth's surface is land and around one tenth of that is arable. This makes a grand total of 14.9 million square kilometres. We may deduce that to grow sufficient sugar from cane or beet would require 34.4 million km^2 of arable land to substitute for the entire world's oil requirement to fuel transport (clearly not feasible) and more than half of it, or 8.8 million km^2 just to keep the U.S. mobile. Unfeasible though these numbers are per se, they must be further regarded against recent estimates that the Earth can only support about 3 billion people, or half the present human population, in the absence of fertilizers etc. and a system of modern agriculture based on oil and natural gas. It should be noted too, that this population is predicted to rise to around 9 billion by 2050, but how can it, when many producing wells of oil and gas will be running out by then?


It makes sense to avoid using arable land to make biofuels, be that hydrogen, ethanol, biodiesel or anything else altogether, since we will need all that available area, and more, to grow food. Alternatives are biomass-to-liquids (BTL) technologies, in which biomass is employed to produce H2 in the form of syngas (a mixture of H2 and CO), and this is then turned into diesel using Fischer-Tropsch catalysts, mostly based on cobalt, similar to those used in indirect coal-to-liquids (CTL) methods, also via syngas. Either biomass or coal can provide the carbon component of the final fuel, but only biomass is renewable. Another advantage of using biomass is that arable land need not be used to grow it and e.g. sustainably managed forests, trees that are planted and harvested according to a managed programme, can provide large quantities of biomass. Other chaff, husks etc. from normal crop production ans sewage and other animal waste might also be included.


This is a huge improvement over using sugar alone to make hydrogen or ethanol, where most of the plant overall is wasted. As an example, sugar cane can produce in excess of 10 tonnes of sugar per hectare, but the entire mass of the crop is over 50 tonnes. If all of that could be used in BTL, the fuel yield would be enhanced markedly. Using BTL diesel, not hydrogen per se, also means that an unfathomable engineering effort of creating an entirely new infrastructure, not even begun as yet, is unnecessary, and the problematic lack of sufficient platinum to make enough fuel cells to use it is immediately obviated.


BTL diesel can be used, handled and distributed by conventional means of tanks and tankers and fuelling stations. If engines were installed as "diesel engines", an efficiency of 20% might be obtained on a well-to-wheels basis, over nearer 14% for gasoline in spark-ignition engines. It is thought that BTL plants will be running by 2020, but producing nothing near the amount of fuel currently used, as derived from oil.


Clever, ingenious and innovative though all the proposed techno-fixes are, it is the engineering - the kinetics - that is the rate limiting factor in their installation. In the case of BTL, the obvious question is, just how many of these plants would we need and how quickly might they be installed? It takes resources to extract resources, whether they be the huge amounts of gas and water needed to squeeze oil from the Alberta tar-sands, or agricultural expansion and the construction of new BTL plants, and the steel, gas, coal, nuclear and other potential resources to provide the basic materials of construction and their fabrication - from the iron ore to the final shiny installations themselves.


If the world's governments had begun work on oil-alternative technologies 30-odd years ago when OPEC made the political decision to marginally close its oil production-valves by 5% (which caused the price of oil to rise by 400%!), we might have realistic alternatives on-stream now. Sadly, cheap oil returned to the markets and eliminated much of the incentives to exploit these other options and now, 30 years later, our problem is not merely political but geological, and we see the world political map shifting in response to the reality of cheap oil supplies in decline, and how each nation, especially the U.S. which uses one quarter of all the oil produced on Earth, might grab more of what is left in the ground.


The age of cheap oil is quite distinctly over - the cost of a barrel of oil has just broken the $100 barrier - and it is debatable how much of any substitute for it might reasonably be produced, including from renewable sources. Electricity production is, in principle, less problematic, since it can be made from a variety of sources, gas, coal, nuclear and, of course, hydro-electric power which should be fully introduced, since overall it is one of the cleanest forms of energy, allowing that it is necessary even here to divert and dam rivers, potentially placing demand on water for irrigation, drinking and other purposes and in some cases displacing large populations, but you can't have it all ways.


The real problem is met in continuing to provide liquid fuel for transportation, admitting that railways can be run on coal, as can shipping, but this is not renewable, and even this estimated great resource will run-out eventually. I envisage a mix of technologies, wherein as much of that as is practicable being from renewable sources. Solar energy is the ultimate, and it is probably best harvested using photosynthesis, to provide biomass and food rather than photovoltaics etc. which will be difficult to install on a large scale, although there is much to hope for. Nonetheless making most of our electricity from solar, in replacement of gas, coal and nuclear power stations is a tall order.


Since it appears almost impossible that we will substitute our current use of oil-derived transportation entirely by BTL (including ethanol, even if the cellulose-digesting enzyme methods can be commercialised in the near future), there will be a significant reduction in transportation, driven by economics and rising fuel prices, along with a rising price of food (both in terms of running farms and imports) and all other commodities. World trade will be hit hard by higher fuel prices, and the prognosis is not good for developing countries such as China who rely on exporting their goods to eager western consumers.


We will increasingly relocalise into smaller communities, provided ever more by local farms and other businesses, and local economies will replace the global village, in the model of Cuba, who moved to a system of farmers' markets when the Former Soviet Union cut off their fuel supplies as the Communist regime collapsed, and there were issues closer to home to be contended with. The Cubans have survived, and so might we, but our lives will change entirely and forever, as we gear-down to a lower-energy society. The horse and cart and the bicycle should be expected as an integral part of the final energy mix, along with whatever technology can provide.


Related Reading.
"Renewables Based Technology," Edited by: J. Dewulf and H. van Langenhove, Wiley, Chichester, 2006.