Is science sometimes in danger of getting tunnel vision? Recently published ebook author, Ian Miller, looks at other possible theories arising from data that we think we understand. Can looking problems in a different light give scientists a different perspective?

Sustainable Energy?

Can society live sustainably? That is a question addressed by David MacKay, a physicist, in "Sustainable Energy — without the hot air", (www.withouthotair.com for a free pdf download) and it is a book I would strongly recommend for reading by anyone interested in this topic. No, it does not, in my opinion anyway, give all the answers, but what it does is more important: the author sets out the way a physicist goes about finding them.  There are places where I disagree, e.g. I feel that too many of his "possible solutions" are somewhat optimistic because by his own admission, he has left out the economic issues. However, what it does is cut through a lot of the "hot air" then considers one very important issue: put numbers on your proposal. My second reservation about this is that the numbers have to be good. In my opinion qualifiers are needed, e.g. for tidal and wave power it is all very well to count up the miles of coastline; it is another thing to actually harvest the energy therein. What is great about it, however, is not the answers he provides, but the framework he provides and the methodology to get them. Read it and see for yourself.
 
Transport is a particularly difficult area. Perhaps because he is a physicist he focuses on electricity to power it, although he does accept that some liquid fuels will be required. These tend to be ethanol and biodiesel, and I shall try to show that this approach is not necessarily optimum in later posts. However, there is no doubt that electrification is optimal for major routes employing public transport. The undergrounds in London and Paris are, from experience, "must use" modes. One problem is that unfortunately the population explosion in the 20th century has led to cities that are too spread-out, e.g. Los Angeles, as well as smaller ones, such as, closer to home, Auckland. Why do commuters in these places not use public transport? Because the workplaces and the residences are scattered widely in a "salt and pepper" fashion. Without major city restructuring, individual transport is going to be required for some time yet, particularly as long as those in residences do not want to be "polluted" with nearby commerce.
 
This book promptly disposes of the hydrogen economy, at least for private transport (I think you have to work with hydrogen to appreciate how difficult leak prevention is) and mainly concentrates on batteries, but it does mention the zinc-air fuel cell. My own view is that more research effort should be put into metal-based fuel cells, but even then I suspect there will be a good place for biofuels. MacKay is correct that so far it is extremely unlikely that biofuels can ever solve the transport problem; it is simply not possible to make enough of them. Nevertheless, there will be some applications where they can contribute, and we may not have unlimited electricity either. As you may gather from my previous posts, I disagree with MacKay when he says municipal solid waste should be incinerated to provide electricity. Resources with carbon-carbon bonds have too much potential to provide liquid fuel. Now it is possible that the economics do not add up, but again, let us determine some accurate numbers for the options before we close them off.
 
After reading MacKay's book there is one almost inescapable fact: if society wants a lifestyle with any resemblance to the current one in fifty years, the numbers simply do not add up unless nuclear power (including the possibility of thorium reactors) is employed.
 
You don't agree? Then read the book and provide the numbers for an alternative scenario. For the one most important point MacKay makes is, arm-waving and adjectives simply do not help. Your theory of what we should do has to add up, and that requires numbers, and some simple mathematics.
Posted by Ian Miller on Mar 14, 2012 10:38 PM Europe/London

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