Saturday, February 14, 2009

Embodied Energy... (or Why Rail is Overrated)

Is BART green?

This study (click here) seems to suggest that the correct answer is no. The reason is that they posit that BART's huge construction costs imply a large amount of energy usage, which is so large that BART's energy savings per trip cannot "pay back" the initial energy used up front.

I'm conflicted, because I think the author ignores the fact that the ratio of $/energy will not be the same for all urban transit systems. BART is a particularly obvious outlier, because it cost far more than similar systems owing to its proprietary track width (every other system uses "standard gauge.") For this reason, BART's cost might be a testament to the cost of designing a system that SHARED NO COMPONENTS with any other transit system rather than being an indictment of BART's construction energy usage. Also, BART is a government project, so much of that money spent will not go to energy-using activities like powering generators but will instead be embezzeled or lost (which throws off the paper's calculations even more). But the study is still an interesting read, and I am interested in seeing more life-cycle analysis of transit which consider transportation usage. Perhaps people should be talking about buses more, as even the study I cited (which is by an anti-transit author) suggests that bus transit saves energy when compared to car-based transit. We might want to consider adopting San Francisco's system of buses powered by overhead cables, which would give bus transit the benefit of lower carbon content as well. The problem seems to be that buses have a stigma in Western society, a stigma that trains do not have. From my own (relatively limited) experience, trains are often filled with commuters who own cars, while buses are generally frequented only by die-hard greenies and people who do not own cars. So I suppose my second question is: should urban transit advocates focus on getting people on buses (which may be greener/cheaper than rail in the long run)?

P.S: This article (click here) explains why none of this means you shouldn't take BART (read "Yes, you should still take Public Transit").

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