We have spent a number of years working in this area alongside charities and companies developing sustainable solutions to environmental challenges.  The facinating thing is how mainstream it has become since we were first exposed to the work that these people do, and how much of it has now become general practice.

BEDZED Eco Housing development
Hydrogen power with ITM Power
One Planet Living
Marks & Spencer and hydrogen power
'Sustainable farming products

(examples include work done in association with Wildflower VC..)