Wednesday, February 01, 2006

An Interesting Comparison

Fuell cell vehicles have always intruiged me, in that they appear to be an environmentally credible way to continue using internal combustion engines into the long term. Despite the fundamentally anti-social nature of a Ferrari V-12, I would hate to never hear one again....

However, really looking at the benefits of still unattainable fuell cells when compared to already existing electric mediums is quite a revelation. What it comes down to is the fact that hydrogen must be split from water, using electricity, then after a rather technically difficult storage either recombined with oxygen through combustion, or within the cell itself, giving off electricity again: fuell cells are of course a direct analouge to an electric cell, dealing with a gas which is extremely hard to store without loss. Which is why an electric cell is inherently more efficient- the electricity can be sent straight to the cell, instead of being first used in hydrolysis. The mechanical process is massively reduced, and therefore net losses are as well.

For 79 Kwh from an electricity source, through the transimission lines (92% efficient) and charger (89% efficient), to the lithium ion battery (94% efficient) and hub-mounted brushless motors (89% efficient), we end up with 60Kwh at the wheels.

For 202 Kwh from an electricity source, with electolyisis (72% efficient) through a pipeline (86% efficient) providing a fuell cell (54% efficient) with hydrogen, the same motors (89% efficient) will again provide the same 60Kwh at the wheels.

This is not to mention the fact that the infrastructure is in place to support electric vehicles. Generation can be added to the grid, and the system I postulated recently would suit domestic use particularly well.

Of course, the petro-chemical empires will push for the establishment of a hydrogen economy, because privatised filling stations will earn you a large profit, and plugging cars in to the mains at home won't.

One can only hope that electric cells can be made slightly less environmentally reprehensible. Imagine the end of life waste if every car was powered by lithium ion batteries....

http://www.worldchanging.com/archives/002685.html
An article (followed by heated discussion) with regard to the efficiency of hydrogen fuell cells versus electric vehicles.

http://www.metricmind.com/data/bevs_vs_fcvs.pdf
Technical data with compelling evidence. The flow chart is of particular interest.

No comments: