I've collected information like this myself. It became pretty detailed, and when put into a spreadsheet I attempted to make performance comparisons. The ultimate goal was to find relationships that would point to furling problems. In the end I didn't get to that stage - mostly because I didn't dedicate enough time to the project before other things to do became more urgent. But the data is still there... if I'm ever seized by the whim again.
Your database can be as detailed as you want: details of site, date installed, date removed, tower height, origin of kit, generator type, blades type, and so on, but asking for the members latitude and longitude isn't really useful is it?
I will sign up and put in the figures for my current turbine. Are you doing an update to the page because the form seems to change every time I refresh it!