Using your solar PV system
A solar PV system is easy to use and runs automatically. You can use the electricity at the time it is generated for free. If you don’t use all the electricity it produces, the remaining amount will be automatically exported to the electricity grid, and you won’t benefit from this.
If you consume more electricity than the solar PV system is producing, you will purchase additional electricity from your electricity supplier.
Solar PV systems cannot store the electricity they produce unless you also have a battery fitted to your home (which most do not). In order to use the electricity produced for free, you must use it at the time it is generated – it can’t be saved for later in the evening.
The above diagram shows an example where 500W of power is generated from the solar panels and a washing machine is using 2,000W. More power is being used by the appliance than is being generated by the solar panels, so an extra 1,500W is purchased from your electricity supplier.
Later in the day the output from the solar panels may rise to 2,000W, which could fully power the washing machine. A further rise in the output of the solar panels to 2,200W would mean 200W would be exported to the grid if no other appliances were also being used.
On a sunny day in summer, a 3kW solar PV system may generate 2,000 to 3,000W in the middle of the day – about the power of a normal kettle. The power output would be less on a cloudy day, early in the morning, in the evening or in winter.