Off-Grid Solar Power System Basics

What is Photo Voltaic (PV)?

The word photo-voltaic is derived from two different words; the word photos, from the Greek, meaning light and the word 'voltaic' developed from the name of the Italian scientist, Volta, who studied electricity. This explains what a PV system does: it converts light energy from the sun into electrical energy.

What is in a photovoltaic (PV) system?

Non Grid-tied PV / Solar System

Solar Illustration
Fig.1. Non Grid-tied PV / Solar System

Fig.1 above picture shows a typical non-grid tied Photovoltaic (PV) System with its main components. It consists of a PV / Solar Panel (Module), Charge Controller, Batteries and Power Inverter. The PV / Solar Panel (Module) converts the solar light energy into DC electrical energy. The Charge Controller conditions the DC electrical voltage and current produced by the PV / Solar Panel (Module) to charge a battery. The battery stores the DC electrical energy so that it can be used when there is no solar energy available (night time, cloudy days etc). DC loads can be powered directly from the PV / Solar Panel (Module) / Battery. The inverter converts the DC power produced by the PV / Solar Panel (Module) / stored in the battery into AC power to enable powering of AC loads

Grid-tied PV / Solar System

Solar Illustration
Fig.2. Grid-tied PV / Solar System

Fig.2 above shows a Grid-tied PV / Solar System. In this system, the Solar Panels (Modules) / Arrays directly feed to an inverter and the inverter is connected to an Electricity Transmission and Distribution System (referred to as the Electricity Grid) such that the system can draw on the Grid's reserve capacity in times of need, and feed electricity back into the Grid during times of excess production. In order to safely transmit electricity to your loads and to comply with your power provider's grid-connection requirements, you may need the following additional items:

  • Power conditioning equipment
  • Safety equipment
  • Meters and instrumentation