How much electricity will a Solar PV installation produce

The amount of electricity a Solar PV installation will produce varies depending on several factors

  • The size of the Solar PV installation
  • The orientation of the Solar PV installation
  • The amount of solar irradiance
  • The angle of the panels

The optimum siting of a Solar PV installation is at 35 degree angle on a due South facing roof, however a Solar PV installation with panels facing either due East or West will still produce a significant amount electricity typically 14% less than what they would produce if they were installed facing due South.

A 4kWp system (16 x 250W panels) should produce 3,434kWh of electricity per annum.  At my house (family of 3 in a 3 bed semi) we use on average 12.8kWh of electricity / day equivalent to 4,672kWh per annum.  Therefore a Solar PV installation could produce 73% of the electricity we use.

EnergyMyWay are looking at ways to maximise the use of the electricity generated from a Solar PV installation and will shortly be installing a battery back-up system.  This system will direct any electricity produced from the Solar PV installation which isn?t being used in the house and use it to charge up several 12v batteries.  In the evening when no electricity is being produced from the Solar PV installation the electricity stored in the batteries will be used to power the household appliances rather than using electricity from grid (which you have to pay for).

After the system has been running for several months we will analyse the results and inform our clients of the viability of using a battery back-up system.

James Eades

By: James Eades

Operations Director, James Eades is EnergyMyWay's in-house expert on renewable energy policy, microgeneration technologies and best practice in the renewable energy industry.