How much electricity will I generate?

There are two things to consider. The amount of energy generated throughout the year, and the amount of power generated at any point in time.

The average UK household uses about 3,000kWh of electricity per year – this works out an an average power consumption of just over 340W. An average 2kW installation can expect to generate 1600kWh of electricity per year. Most houses can fit 2kW of solar panels on the roof – although some can fit 4kW or more. If you are sensible about how much electricity you use, you could easily make your house “electricity neutral” when averaged throughout the year.

In ideal conditions (which will never occur) on a clear June lunch time, a 4kW south facing array should generate about 3.9kW. If the roof faces west it should peak at about 3.6kW a few hours after midday. In winter, the south facing array should peak at just over 2kW if facing south, but might only reach 1kW if facing west.

It's always nice to know what you are generating from your array! Although the official kWh meter that we install will measure the total amount you have generated over the lifetime of the system, it's usually hidden away in a cupboard somewhere, and doesn't in any case tell you what you are generating at any given moment.

So we give you a wireless energy monitor so that you can keep an eye on what your array is generating. It is very useful to know how much power the array is generating at a given moment, as you can save considerably on energy bills by arranging to use power from the solar array when it is available for appliances such as washing machines and dishwashers.