When I was doing some research for this project I found very little information so I thought I'd post a few pics and information
We've got a 20*20 foot concrete patio off the back of our house on the way to a small in ground pool (12*24). The patio is quite nice but basically unusable in the summer here without any shade! I was seriously interested in an Alumawood solid roof but due to the snow load here in the mid-Atlantic region the footings needed were substantial and would have required cutting into the patio.
Thought about a Sunsetter retractable deal but they only go out a max of a little over 11 feet. I wound up with the system from ShadeTree - http://www.shadetreecanopies.com . Very happy with the results, the canopy is 16' wide and projects 15', each section is retractable seperately and when retracted it tucks up under the eave. I did some prep work before the tracks and fabric arrived, took about a day and a half to build the wood frame from materials acquired locally and I stripped off the vinyl siding / installed a ledger board and flashed it in. Once the shipment arrived it was about a 5 hour project to erect it with a bit of assistance here and there from my wife.