Many houses in the UK are suitable for Solar Panels and can in some way shape or form benefit from solar panels and solar energy. Most installers will however be looking for certain key factors which really determine and make up the potential for your house to make the most of solar energy. These factors are extremely important in determining the monetary gains and the practicality / feasibility of installing solar panels onto your roof.
The important factors
How shaded is your roof?
Installers will be looking to select roof space with absolutely no shading, or keeping it to an absolute minimum. The reason is quite obvious in that if the suns rays are not hitting the solar panel the potential for power creation is going to be hampered. Shading is commonly effected by chimneys, trees, radio / tv satellites or surrounding properties. Many installers will work with you to remove or install solar panels only where there is an absolutely minimal amount of shading if any at all.
Orientation of your roof?
The orientation of your roof, is a massive factor when determining the feasibility of a proposed solar panel installation. The optimum in the UK is due south, this is due to us laying in the Northern Hemisphere and the Equator being to the South (Read more about the Geography here). A due South roof will see more hours of sunlight on average per year, and thus is the optimum on non moveable installations – read more about solar panel mounts. Panels can still be reasonably efficient when facing west / east, but less so that any due south orientation.
The angle of your roof?
The pitch / angle of your roof or installation area will play a bit part in the amount of sunlight your solar panels will see and therefore the amount of solar PV that will take place. The most common pitch for a rook in the UK is between 30-45° many installers will have their own theories on which is better, depending on whether they optimise for certain times of the year more than others or whether they go for an average angle over the course of a year.
A useful addition to this set of questions would be the standard method of calculation in the UK using the Standard Assessment Procedure (SAP). The equation for this is:
Predicted Generation (kWh/year) = Irradiance x Shading factor x kWp x 0.8
The production of energy will vary across the course of a year, obviously during the winter months when we receive less hours of sunlight per day and with less strength than during the summer months, the solar panels are likely to make significantly less energy than during the summer.