In the majority of installations, these modules connect to the electricity supply via a ‘grid-tie’ or synchronous inverter. Electricity is provided to the building whenever there is light and is exported to the grid whenever production exceeds the building’s demand.
There are many different forms of photovoltaic systems - amorphous silicon, polycrystalline, monocrystalline and hybrid - each with its own benefits and drawbacks, and requiring specific installation techniques.
Shading, inclination and orientation are critical to output. Optimum performance is achieved when unshaded, with a 30º inclination and south facing. Orientations 45º either side of south (south east to south west) are considered to be acceptable.