Rooftop solar, Gurab Zarmikh

The brief

The client had a high electricity bill and an unshaded south-facing roof. The requirement was to cut the bill rather than to leave the grid, so the system was designed grid-tied and battery-free to keep the cost where it does the most good.

How it was done

1. 01 Twelve months of bills reviewed and capacity set from actual consumption
2. 02 Shading from surrounding trees checked across the day
3. 03 Galvanised mounting structure calculated for local snow and wind loading
4. 04 DC runs in protected containment, with a fuse and isolator per string
5. 05 Surge arrestors on both DC and AC sides, given how often the area takes lightning
6. 06 String insulation tested and an I–V curve recorded at commissioning

The outcome

The array produced from the day it was energised, and the handover pack of single-line diagram, string schedule and commissioning report went to the client. An annual service was set up for panel washing and connection inspection.