However, what needs to be considered is how the slope of your roof (or lack thereof) will affect any solar panel yield. The ideal roof pitch angle is between 30-40°, but even if the angle of your roof falls outside of this range, it is still possible for a PV system to generate clean electricity effectively.
Installing panels at a fixed angle might capture less sunlight during winter when the sun is lower, meaning you won't get as much energy for your home. The optimum angle for solar panels on flat roofs is around 30 to 35°. This angle helps the panels balance, maximising solar energy production and allowing rain to flow off them easily.
If the roof is flat or nearly flat, it may be desired to tilt the solar panels on the roof to achieve optimal angle toward the Sun. The PV mounting system can often include standoffs of various heights to increase tilt. The illustrations below depict common roof pitches and their angle degrees for quick reference in identifying your roof.
In the UK, solar panels produce most power when mounted at between 30 and 40 degrees to the horizontal, facing due south. It is therefore natural to assume that this is the best angle to tilt them at for flat roof installations. But this is not usually the case, as there are other factors that come into play with flat roof mounting:
Generally speaking, any angle between 45° and 85° is ideal for a rooftop solar system. These kinds of angles expose a lot of surface area for the photovoltaic cells to absorb as much sunlight as possible. Homeowners with a roof pitch between these angles should see much higher levels of efficiency.
As water runs downwards and off the panels, helping to clean the panels in the process. A roof pitch will impact the amount of energy your solar panels collect from the sun – most are installed flush in-line with the roof pitch and raised a few inches above.