Solar power was an afterthought. Sort of.
When we bought our house, one of the "custom" additions requested from the builder was to run power under the concrete walkway that surrounds the house. They screwed up and long story short there was no external power under the walkway. So, the only way to run the power 50' away from the house was to cut through existing walkway, sprinkler and drainage systems, etc. I compared the cost between that job and installing a 400W solar power off-the-grid kit and decided to give solar a try. Sometime during early stages of building the observatory I picked up another solar power kit, this time for the garden shed, but then finally came to terms with the fact that I really have no need for power in that shed... So, now I had two solar power kits, 600w of solar power - it was time to figure out a way to mount 6 panels get the rest of the kit components installed.
I designed a slide-out platform based on the super heavy duty 68" slide out rails, a pair of which are rated to support 500lbs at full extension. Side out rails were secured to the roof and then to the panels via aluminum L-beams. Rest of the installation relied on industry-standard IronRidge mounting rails, brackets, bonding hardware, etc. The key was to figure out how to make the connections flexible to accommodate the moving rack. I decided to use a flexible 3/4" conduit and MacGyvered a small network of conduit pipes, connectors, and electrical boxes to run all the wires and get it them secured and sealed up. This conduit is hidden under the solar panels when the rack is closed and are completely out of the way, running alongside sliding rails when the rack is open.
Once the rack was fitted, secured and tested, it was time to connect and mount the six 100w panels. Each panel is about 27"x41" and weighs in at just under 19lbs. The combined set created a really nice 6.75'x6.83' roof cover above the roll-off opening with a total weight at just under 150lbs including the mounting rack and rails. The entire setup slides out effortlessly and the rails are butter-smooth. When racked out, the panels are completely out of the way and do not obscure any views.
During the water-tightness test (fully opened garden hose!) I discovered that although I've sealed the Retrax roll-off all around, there was a possibility of a leak if the water was was standing at some of the edges and was then forced in by strong winds. I solved that issue by adding a simple corrugated "lid" that I fabricated from corrugated plastic sheet that I simply add when it's the rainy season and I know i won't be using a roll-off for quite a while. It takes all of 3 seconds to add or remove, so I might just use it all throughout the winter.