There are many roofs particularly commercial roofs which are flat.
For northern part of Australia, flat roof only creates minor reduction in solar generation overall. However, for southern states this makes it worse in winter months, particularly Victoria and Tasmania.
For Brisbane with flat roof there is generally only 7% loss in overall power, however in winter months this makes to 26% loss.
For Melbourne with flat roof there is only 8% loss in overall power, however in winter months 26% loss. Note, winter months are already short in Melbourne, so the flat roof will infect make the matter worse.
The flat roof also accumulates small amount of dust, so a nice wash regularly can keep performance better, particularly during dry months.
The trade off for the flat roof is to oversize the system with more panels. This generally works well, however will not avoid dust accumulation during dry months, particularly near busy dusty road.
If the roof space is large enough, also noteworthy is to add tilt frames if the system size is small. The tilts add extra cost though. Remember, panel arrays need to have enough space, so the front array doesn’t shadow the back array, particularly in winter.
If roof is small, and flat and you don’t want to install tilt frames, Power Optimisers such as SolarEdge will help getting maximum performance out of the solar system. They cost slightly dearer, however will make best performance out of the system. You can also add tilt frames onto only one of the back arrays to get maximum output and avoid shading.
Contact us to design a right Solar System for your property.
