For those who have not heard of David Mackay, his book "sustainable energy without the hot air" is areal must for everyone who is interested in sustainability, or who uses any type of energy source.

The link to the free PDF is below.

http://www.inference.phy.cam.ac.uk/s...tex/sewtha.pdf

David Mackays website is here : http://www.withouthotair.com/about.html

I found it a refreshing, thought provoking and informative read, all the statements are full quantified and qualified, rather than hyperbole and illinformed opinion that can often arise around the subject.

I would be interested in hearing others thoughts, after all this is what forums are for.