Calculate the estimated performance of your solar energy system…

Click either of the images below to work out your annual electricity output, with the annual cost savings and annual carbon benefit of having Solar PV or Solar Thermal installed.*

The SAP 2009 calculation is the government’s official calculation procedure. SAP stands for ‘Standard Assessment Procedure’. This method takes account of roof orientation, slope and shade; however it doesn’t take account of latitude, so if combined with a more detailed report based on your location you may find that we can provide additional data as to how your individual system may perform.

To do this, we use recognised design software such as PVSol, which uses more localised weather data along with greater detailed input capability, and should provide an additional, and in our experience, more accurate projection of output.

To run your own estimate* click here for Solar PV and click here for Solar Thermal.

How your system is expected to perform by month

You’ll get the highest levels in May to August, with only 10% output in November through to January. If your panels will be shaded by low level light in winter, don’t worry, it won’t make much difference to the overall performance.

* Statutory disclaimer: The performance of solar energy systems is impossible to predict with certainty due to the variability in the amount of solar radiation (sunlight) from location to location and from year to year. This estimate is based upon the Government’s standard assessment procedure for energy rating of buildings (SAP) and is given as guidance only. It should not be considered as a guarantee of performance.