biofuels
Today's top story on he BBC is about candidates for the Conservative Party leadership. It's all meaningless sound bytes, with no substance worth discussing. In the absence of a real story, here's something on biofuels.
My daughter (age 14) is to give a presentation on alternative energy at her school. Her teacher had prepared a summary of the issues to start her off. My personal favorite energy source is biomass - you grow it, burn it, and grow it again. Very simple technology, zero net emissions, a much bigger and more stable market in fuel, so everyone wins. So I was interested to see what her teacher's notes said about biomass: nothing. However, it did have something to say about biofuels (where you turn biomass into ethanol for more concentrated energy). It quoted research by David Pimentel, saying that biofuels use more energy to create than they produce, they require too much land, and they have serious problems with emissions - notably Nitrous Oxide (NOx) and the carcinogenic aldehydes. So I did some research, and guess what, Pimentel (and hence my daughters' teacher) is wrong on all counts.
Most researchers agree that biofuel creates a net increase in energy. See http://www.b100fuel.com Actually, it wouldn't be a fatal blow even if the overall energy balance was low or even negative. Biofuel is important because it concentrates energy so as to be portable - e.g. for cars. Its great benefit is that it is portable, not that it is efficient. Every battery takes more energy to produce than it gives out, but batteries still play a useful role.
Biofuels do use more land, but that can be an opportunity, not a problem. Biomass can be grown anywhere that there is sunlight and irrigation. At present, we import energy from just a few producing countries, and that leads to war and injustice. If we used biomass, far more countries could enter the market. Imagine vast areas of North Africa turned over to cultivation. We improve the environment, reduce poverty, an create a more stable market in one go. And of course biomass does not have to provide all the energy - there is also solar power, wind power, tidal power, wave power, efficiency savings, geothermal power, etc., etc.
NOx emissions depend on the type and use of the engine. Some research shows that it actually goes down. See http://journeytoforever.org/biodiesel_nox.html Similarly, aldehyde emission are not any higher than with conventional diesel - see the final report to the US department of energy on the subject. And remember that the main greenhouse emissions - like CO2 - drop to zero, because all the CO2 is reabsorbed into the next generation of biomass.
Any major change will have costs, even if instituted gradually. But compared with the costs of global warming (reduced coastline, global unrest, famine) or the costs of nuclear power (waste and decommissioning, accidents, availability of weapons-grade material, some of which will always be lost), biomass and biofuels are the bargain of the millennium.
posted by Chris Tolworthy at 9:32 AM
4 Comments:
I am a fan of alternative energy, especially energy that can be generated more on a local scale. A couple of things I think you may consider is the change in enviroments when land is converted to agriculture, the demand for fertilizer and the pollution it tends to create and water; ground water tables are dropping in the food belt of North America, rivers such as the Colorado barely dumps any water into the ocean now due to the extreme demands. Still I am a fan to alternative energy research and application. Solar power catches my attention because it is possible not to be at the mercy of the power providers.
Wind power is actually getting attention in Oregon and Washingon Wind Power
ie85 - yes, its all a question of politics. I suppose this is illustrated in my daughter's experience: she will probably never get to present these specific results in class, because she has been given just five minutes to cover every aspect of alternative energy. Worse, she is to do it with a group of other girls who have little interest in the subject and find it hard to work as a team. here I think we have a microcosm of how real world energy politics works.
trail seeker - I agree. Local is best. (I live in a windy area and would love to place a turbine on my roof if my neighbors would agree.) As for the problems of intensive agriculture, recent news reports (suggesting that Europe could get ten percent of its energy from elephant grass, and Ireland could get thirty percent) seem to suggest that fertilizer, etc., is not a problem. I am no farmer, but I am sure that they would at least need some kind of crop rotation at a minimum. Anyhow, I watch with interest.
re: algae. Now that is a brilliant idea. Seriously. The whole point of biomass is to efficiently convert sunlight (or other nutrients) into raw mass, so it makes sense to use the simplest organisms possible to do the raw grunt work. No doubt there are obstacles to overcome, but if we could channel the money wasted on fusion reactors, for example... I speak as someone who studied physics at university, and I love fusion as a concept, but biomass is just a much better idea in every way.
Regarding the "area the size of Rhode island" concept, this reminds me of when I first woke up to "alternative" energy. I was studying energy at the aforementioned physics course. In the introductory lecture we were given various statistics, including the sunlight that falls on the UK and national energy consumption. The exact same week, the BBC news reported that, to satisfy EU regulations, British farmers would have to "set aside" a land area the size of Devon. I did a quick calculation. If that area was covered with solar cells of 25% efficiency, Britain';s energy needs would be solved. Obviously that was a crude calculation (25% efficiency is unlikely for a start) but it made me realize that there is no scientific reason why we can't have one hundred percent renewable engine.
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