There are several roofs with varying orientation and inclination at this property, but none of them are ideal for mounting a photovoltaic array. However by using BenQ Sunforte 330 Wp modules we have been able to squeeze a 3.96 kWp array onto a relatively small roof with the most favourable orientation.
The BenQ modules are built from ‘back contact’ solar cells which achieve higher conversion efficiency (> 20%) by moving the metallic front contact grid to the rear of the cell. This means that a smaller surface area will generate a greater output than is the case with standard PV modules.
To mitigate the impact on performance of shading from nearby trees, we used a SolarEdge inverter with individual power optimisers for each module.
Surplus power from the array is diverted via an Immersun PV switch to an immersion heater in the hot water storage cylinder. This reduces the costs of heating hot water for much of the year.