Solar panels quotes

Most roofs face more than one direction, so panels can go on more than one side and catch the sun across the day. Orientation, pitch and shading all affect how much you generate.

The real suitability question is how long you are staying, which is covered below.

Start with the payback, because it is the least attractive part. Realistically you are looking at fifteen years or more before the system pays for itself, and longer if your roof is east or west facing, shaded, or further north. Unless this is the house you plan to stay in for a long time, that is a hard number to justify.

What you are paid for the electricity you export makes a real difference, and the rates vary enormously between suppliers. The best rates are usually reserved for customers who bought their system from that same supplier, so it is worth asking what you would actually be paid before you choose an installer.

A battery deserves a straight answer. It lengthens your payback rather than shortening it, because it costs more than the extra electricity it saves. What it buys is usefulness: in summer your own generation can run air conditioning and charge a car instead of being exported cheaply. That can be well worth paying for, but it is not a way to get your money back faster.

Ask what annual generation they are predicting and on what assumptions. Ask what they assume you use during the day, since that is what decides your saving. Ask about scaffolding and roof condition, and whether the roof needs work first. Ask what the inverter's expected life is and what replacing it costs.

A payback figure far shorter than ten years. Savings quoted without any assumption about how you use electricity. A quote that never mentions roof condition. Finance presented as the main reason to sign today.