In many ways the rapid uptake of PV in Australia over the last decade has caused the city-based PV installer a problem: many of the easy, large area, unobstructed, north-facing roofs have already been used. Often this leaves us with “sub-optimal” installation options involving small areas where only 1-4 modules will fit, roof areas that face in multiple orientations – thus precluding the use of a simple string inverter – and roofs with transient or even permanent shading. Other issues include customers wanting to expand old systems, typically with modules in the 165-190Wp range which are expensive and hard (if not impossible) to source matching modules for. Simultaneously, we have seen a tightening of standards and an increase in awareness of potential safety issues around unprotected LV DC cabling, resulting in the need to provide additional mechanical protection for the cables inside buildings via the use of HD conduit or, in non-domestic installations, ducts or cable trays with lids. The mandatory use of rooftop isolators on PV systems has also seen its own set of issues with multiple recalls of faulty DC isolators over the last few years.