Solar Glossary of Key Terms

There are many technical terms used in the solar power industry. Definitions for some key terms can be found below:

A.C. Power A type of electrical current powering household and business appliances.

Appliance Controller An additional component that can be added to a grid-connected system. It allows you to select appliances to be automatically switched on when solar power is being generated. The appliance controller monitors the amount of solar power being produced and will turn the appliance on when there is excess solar power. 

Azimuth The Azimuth measures the horizontal angle or direction the solar panels are facing. A 180:° azimuth is when solar panels are facing north, -90:° azimuth when solar panels are facing east, and 90:° azimuth when facing west.

Balance of System (or BOS) Refers to all other components minus the solar panels and inverter. Therefore, it is the mounting system, wiring, conduit, switches, labels and any other hardware required for the solar power system set up.

Batteries Deep cycle batteries are required for off-grid solar power systems and grid connect systems with battery back-up. The main types of batteries used are gel, lead-acid and AGM batteries. Relatively new batteries on the market include lithium and sodium-ion.

D.C. Power A type of electrical current produced by solar panels, which is then converted into A.C. Power

Depth of Discharge A term that describes how much a battery can be emptied e.g. 70% depth of discharge.

Inverter It is a device that converts DC electricity from solar panels into AC electricity.

Kilowatt Hour (kWh) A measure of electrical energy equivalent to a one thousand watts for one hour. I.e. using a 2000-watt heater for an hour is 2-kilowatt hours.

Monocrystalline Solar Panels Panels with solar cells, made up with a single silicon crystal.

Photovoltaic (PV) A material that creates an electrical current when exposed to sunlight.

Polycrystalline Solar Panels Solar panels with solar cells, made up of a number of silicon crystal ingots.

Solar Array Any number of solar panels wired together to maximise electricity being produced.

Solar Panel A solar panel is made up of individual PV cells, glass and an aluminium frame.

The Grid Refers to the infrastructure set up to transport electricity from power plants to home and businesses. The local grid is the network of cables that distributes power throughout a town or city. The high voltage grid connects the large-scale energy plants to the local grid.