Solar Photovoltaics (PV) Basics

Photovoltaic’ is a marriage of two words: ‘photo’, meaning light, and ‘voltaic’, meaning electricity. Photovoltaic panels form part of a solar PV system, creating energy from sunlight.

Solar Cells

Solar cells are the basic building blocks of a PV system and consist of semiconductor materials mainly made out of silicon. When sunlight is absorbed by these materials, the solar energy knocks electrons loose from their atoms. This phenomenon is called the “photoelectric effect.” These free electrons then travel into a circuit built into the solar cell to form electrical current. Only sunlight of certain wavelengths will work efficiently to create electricity. PV systems can still produce electricity on cloudy days, but not as much as on a sunny day. The performance of a solar (or PV) cell is measured in terms of its efficiency at converting sunlight into electricity. There are a variety of solar cell materials available, which vary in conversion efficiency.

Solar Modules

A photovoltaic module is an array of photovoltaic cells pre-arranged on a single mounting mold. The type of module is therefore determined by the cells that compose the nodule itself. There are three common cell technologies namely monochrystalline,polycrystallnine and multicrystalline

Basic Solar PV System components

Component

Purpose

PV Module

Array of photovoltaic cells pre-arranged on a single mounting mold

Inverter

Used to convert DC electricity produced by solar panels to AC electricity used by appliances

Charge Controller

Regulates battery voltage and ensures that batteries are charged properly.

Battery

Used to chemically store direct current (DC) electrical energy in a PV System

LED Lights

LED lights are energy efficient bulbs the latest technology in lighting and offer a great alternative in replacing conventional lights

Balance of System (BOS) components

Components that move energy produced by solar panels through the conversion system which in turn produces AC, e.g. cables, switches