OpenStreetMap
Tom Chance has built a KML that presents power generators in the UK - it's an extension of one he made for London, and here it is: http://tomchance.dev.openstreetmap.org/kml/power_uk.kml
So, I've been checking the tags of the Ecotricity wind farms and very fine they look. It would make a great school project, having kids scurry around finding all the green gennies in their patch.
Tagging guidance here: http://wiki.openstreetmap.org/wiki/Tag:power=generator
Discussion
Comment from Donald Allwright on 18 September 2010 at 22:46
With the rise in the number of grid-connected photovoltaic installations due to the new feed-in-tariff in the UK, should these also be added? There is mention of them on the wiki page but this specific issue is not addressed. This information will no doubt be of interest to a niche market but (a) is unlikely to be complete as not all installations will be visible from a public highway, and (b) may raise specific privacy concerns as they are usually located on private houses.
Comment from andygates on 20 September 2010 at 07:51
I'd say so, yes (Tom's point with the original London KML was to show how many of these microgenerators there are). The generator:output subtag might come into use here: a renderer could choose to hide or display smaller-scale generators as appropriate.