Grid-Connected Systems

Grid connected systems are used in properties that have a mains supply but where the occupier wishes to contribute to the battle against greenhouse gases, by reducing the demand for electrical energy produced by burning oil or coal.  During the hours of daylight the solar array converts radiant energy into electrical energy, which is passed to the DC/AC inverter, which creates 240V 50Hz and synchronises it with the mains supply.  This locally generated power is connected to the buildings consumer unit and at times when power demand is modest, will supply power to the household appliances.  At times of greater demand or darkness the balance of power is drawn from the grid.

Connection of such a system requires approval from the local electricity supply company.

It should be noted that for specific safety reasons the inverter automatically switches off if the mains fails, this is not therefore a standby power system.

So will I have free electricity?

As a rough guide, a 1kwp PV array mounted on a south-facing roof, which is not shaded, will generate approximately 850 units (KWH) per KW of installed solar modules.

It will also save in the region of 300KG of carbon dioxide going into the atmosphere per year.