yes,,it will be, because the potential is varying from location to location. it will will help to establish which technology is best for a specific location.

LCA would be a good method to analyze sustainability. Actually, the more complex the system to be analyzed the more complex the LCA -- I doubt that it is possible to do a more or less complete LCA of such complex systems like a wind mill or solar plant.

A 1MW wind turbine will have a different power output as a 1MW PV array.  A direct comparison of environmental impact of the two therefore does not give much useful information.  It would make more sense to compare the environmental impact per kWh produced of typically sized units.  There is already quite some literature about the subject that can be easily found using Google Scholar.  I would recommend to look into this literature to see how it is done.