My understanding is not all the effects of windfarms on radar are fully understood, especially SSR where you have effects like backscatter and shadowing, so there is a zone around radars within which any windfarm application will be objected to. As for the BAE solution this is still some way off and will need to have some money thrown at it, although the Americans have just placed a mighty big order with Raytheon for primary radar so it could be that a solution comes from that (red)neck of the woods.