How Solar Panels Work

Basically, solar panels harness the sun's rays to produce electricity.

A solar panel (also referred to as photovoltaic or PV cell) is primarily made of silicon, and consists of electrons, which are unable to produce electricity in their natural state. When the photons of light within the sun's rays strike the silicon surface of the solar panel, they react with the electrons within the solar panel to produce electrical charge.

The electrical charge produced by the solar panel is in Direct Current (DC) form, similar to the voltage of your car battery. This voltage is suitable for charging a 12v, 24v or 48v battery bank, but it is not compatible with the electricity that flows throughout your home. The electricity then needs to be inverted from DC to AC (Alternating Current), in order to provide electricity for your household appliances.

A standard solar panel available from EnviroGroup is 170Watts. This means the solar panel, in perfect conditions, is capable of producing 170 Watts of electricity. It also helps to understand why a system with 6 panels is referred to as a "1 kiloWatt system", as 6 x 170W panels equates to 1020 Watts (or 1.02kW).

These 6 panels are capable of producing around 1kW of electricity per hour, through the middle of the day. On average in Melbourne, you would expect to produce around 6kWh (kiloWatt hours) per day in the height of summer, and as low as 2kWh per day in Winter. To summarise:

6 x 170W panels = 1000Watts = 1kW

1kW system produces 1kWh per hour        

Sunlight in Melbourne = 4 effective sunlight hours, averaged out over the year, Therefore = 1kW system produces approx 4kWh per day over the year

Naturally these figures are higher in Summer, and lower in Winter. You could reasonably expect to produce up to 6.5kWh per day in Summer, and as low as 1.5kWh per day in Winter (because there is less effective sunlight), so the average of 4kWh is quoted as a yearly average.

This equation applies to a solar array of any size, therefore a 2kW system would produce an average of 8kWh per day over the year, a 5kW system would produce approx 20kWh per day, and so on.

To determine how many solar panels you might require, you can find your daily kWh consumption on your electricity bill, and compare it with the figures above. The average home in Victoria uses 12-15kWh per day, but this can vary greatly.

The SunOwe, Suntech, BP Solar or Schott panels that we install come with a 25 year warranty, to 80% of their rated output. This means a 170W panel is guaranteed to produce a minimum of 136Watts after 25 years. If you have any concerns about the output of your system, please contact EnviroGroup.

Where to next?

Different types of solar panels available (mono, poly, amorphous)

Why are some panels much cheaper than others?

Other Solar FAQs