We have sized the PV array and the battery bank; we have selected a controller we now need to specify the inverter as it is the component which will make our PV system usable by AC appliances.

When sizing the inverter you should keep in mind that:

• One; it will have to supply enough power to run the peak load as determined in the load profile
• Two; the inverter conversion efficiency should not affect the system's power supply capacity and,
• Three the inverter DC input voltage should match the system voltage

The inverter is first selected on its capacity of supplying enough power to handle the peak load. Other factors which will influence the specification are:

• System voltage which should correspond to inverter input voltage
• Inverter's output voltage should correspond to the load nominal voltage. 240Volts in Europe and Africa and 120V in USA.
• The inverter should maintain a frequency of 50Hz in Africa and Europe and 60Hz in USA
• The inverter should have enough surge capacity to start motors. Most inverters are able to exceed their rated power for limited period of time. That is necessary to power electric motors which can, at starting, draw up to five times their rated power.