Creating an alt energy co-op

I live in a townhome community in Denver with 250 units( approx. 2100 sq. ft. on three floors, 700 sq ft. roof area). Each unit has its own roof, we have a large clubhouse with an excellent roof for solar panels and additionally we have about an acre of grass in the middle of the complex and other areas that could accommodate wind turbines. We are right next to three other similar complexes. I have contemplated for the last year, and that is all, how one complex or all four could come together and create a 250 to 1000 member alt enery co-op. I know there are government grants and Xcel energy, our local energy co.,has rebates and will buy back excess energy. Any ideas?