Hermann,
Following your post I had a closer look at the community corrected EPER coordinates. It seems that in some cases the community members who changed the location of the site moved it to the middle of nowhere. Several of the times they did this they left their name and email address and the new coordinates were created using my interactive map rather than just typing in random coordinates. Because of this I wasn't able to filter them out as I do with other "vandalisms". As my website is only in English it could be due to language barriers, but it is very different to what I have observed in Australia where there is very little data vandalism on my Renewable Energy and NPI posts.

Therefore I will also filter out community changes that are more than a certain distance from the Google Maps corrected location. I will upload a corrected KML file. In the meantime I have attached an analysis of 158 sites that have original (red), GMaps (green) and Community (blue) coordinates for comparison. Where the red marker is a long way from the other two it indicates the original coordinates were very wrong (common in Spain). Where the blue marker is a long way from the other two I believe it indicates data vandalism in most cases (common in France). Where the green marker is all alone it indicates bad geocoding from Google Maps (common in Finland).

I would be interested in comments from others on the issue of community input into location data and ideas as to why some people would enter erroneous data and whether I can collect data in a better way.