TrekHaus duplex's West unit gets 4.70 kW (20 panel) system. SolarCity worked with us to design a custom racking system using Schletter rails which mount on the parapet walls of our low slope roof, maintaining the integrity of the white FiberTite roofing membrane. The solar panels will operate more efficiently on a cool white roof compared to a more conventional dark roof. The custom design also allows for abundant air flow underneath and around panels which further enhances efficiency. Five solar panels mounted per rail pair with four rows. For our particular installation on south-facing low slope roof, the panels are mounted at a 5 degree angle. With current system, West unit is on track to be net-postive. Will monitor awhile before installing panels on East unit. Thank you SolarCity! Thanks also to David Swyter (Total Home Inc.) for installing the high performance roof!
Photo credit: Kevin Jahangiri from SolarCity