The offices are all connected by a walkway 2 m wide. The walkway roof incorporates 50 PV Siemens Model M55 panels, each measuring 800 x 400 mm and rated 55 Wp. The modules are inclined at about 24 from the horizontal.
Open circuit voltage is 17.4 V, and short circuit current is 3.15 A. The roof has a total power rating of 3 kWp, and can export to the grid via an inverter.
The rest of the walkway roof, including the porch, is made of
laminated glass sheets, colour-matched to the PV panels. The design of the PV integration uses the laminate mounting extrusions as the structural members, while providing ventilation at the rear of the laminates. Details for
flashings were developed to allow attachment at the interface between the existing uneven granite wall and the head of the PV roof, while allowing ventilation air to escape. All the external surfaces have been coated with epoxy
The PV arrays (three strings of
16 modules) are interconnected in junction boxes within the ceiling of the walkway to allow access for research and testing. Two extra modules have been left unconnected for later
monitoring. DC wiring from each array is fed to an inverter in the plant room, located near the end of the walkway. This feeds the distribution board for the offices. Excess power is exported to the grid.