Solar photovoltaic generation systems use solar panels to convert the energy from sunlight directly to electricity. Solar panels may be

• Crystalline,
• Polycrystalline,
• String,
• or Thin film.

The output voltages from these panels are standardised to be able to charge banks of 12 Volt batteries (if used).

The electricity geneated by the solar panels can be used directly, but is more often stored in rechargeable batteries after the voltage has been converteted to a suitable value by a charge regulator.

In most cases, people need a 230 volt AC output to power appliances and for lighting. A device called an inverter is used to step up the battery or solar panel voltage (if a battery is not used). Inverters may be

• Off-Grid,
• Grid Tie or
• A combination of both.

When a grid-tie inverter is used, the solar power generated is fed back into the AC grid when a surplus of power is generated. With this type of inverter, when the power goes off it stays off, even if the sun is shining.  Grid tie inverters of any type are not legal in South Africa.

When planning the installation of a Solar PV system, it is important to reduce the amount of electrical load by carrying out a survey of equipment usedand then assessing how savings in demand can be made. At the same time ay increased costs due to the demand savings can be estimated. Examples would be using CFL lamps (which cost more) instead of incadescent lamps (which demand more electrical power).