Solar panels are usually advertised by their peak power rating, but that figure doesn’t tell you how much electricity they will generate on your roof over a full year. Real-world output varies according to the size of the system, your solar panel’s efficiency, where you live, the direction and pitch of your roof, shading and even how efficiently the panels and inverter perform.
A typical UK home system is now around 4.5kWp, but two systems of the same size can produce noticeably different amounts of electricity if one is south-facing in southern England and the other is shaded or installed farther north. Solar generation also changes sharply with the seasons, with most electricity produced between spring and early autumn.
