Solar Photovoltaic (PV) systems generate electricity from the sun to be used in your home. Typically these are installed ‘on-grid’ with an inverter which exports the excess electricity which you don’t use to the grid.
We can also offer ‘off-grid’ solutions with battery storage. These are usually implemented in remote locations with no grid connection due to the high costs of maintaining the battery bank.
We have more information about how solar systems work in the technologies section.
Solar arrays work best in this country when orientated to the South at an angle of about 30-40°, with no shading. However, roof spaces orientated up to due East or West with the panels at other angles are also viable. Shading of the array by nearby objects should always be avoided but can be managed.
Solar arrays can also be installed on flat roofs and ground mounted on a-frames if you don’t have a suitable pitched roof available.
We can provide you with a quick assessment of the suitability of your roof and give you estimated prices and payback time over the phone so please contact our technical team.
Solar PV system sizes are quoted in watts (W) or kilowatts (kW, 1000 watts). This is the peak output of the array in test conditions. Because, this figure is based on the universally approved testing methods required for all MCS accredited panels it can be used to accurately compare the performance of different systems.
The performance (output) of a solar PV system is measured in Kilowatt hours (kWh) – the actual energy produced over time. Your electricity consumption is also measured in kWh so we can compare the two.
When comparing two systems from different manufactures the kW peak of the system can be the same but the more efficient panels will use a smaller surface area to achieve this. For example a 4 kW Sharp system with 15% efficient panels will need area of approximately 30m² whereas a 4kW Panasonic system with 19% efficient panels will only need about 25m² to give the same performance.
We typically size the array based on your available roof area, budget and to maximise the payback from the Feed in Tariff. The Tariff is tiered into levels by kW. The below 4kW tier is suited to a typical house and receives the highest tariff. We sometimes install systems in the 4-10kW tier for domestic properties as well. In both cases the closer the system size is to the top of the tier the better the return will be.
Savings and return on investment
Solar PV systems are eligible for the Feed in Tariff, which was introduced to increase small scale renewable electricity generation in the UK. The tariff has meant that Solar PV is now a very good investment opportunity and with high demand costs have fallen significantly. Further information on the benefits of the scheme and the currents rates can be found on our grants and funding page.
Looking at a typical 4kW system installed in an optimum position, we typically expect an annual return of 8-10% based on current rates. This means that the cost of installing the system will be paid back in about 10-12 years. The tariff rate is fixed (index linked) for 25 years once you have signed up. We would expect you to at least double you investment over the lifetime of the tariff.
We will provide you with an estimate of the predicted performance for your array taking into account its size and siting.
Please see our case studies page for exples of our PV installations.