Call 1300 076 188

How many solar panels do I need for my family?

There is a growing trend for Australian households to install solar PV system to help both reduce greenhouse gas emissions and save on energy bills. Between 2008 and August 2013, the combined capacity of solar photovoltaic (PV) systems installed across Australia has increased from 29.3 megawatt to as much as 1031 megawatt[i].

How much electricity do you use?

According to statistics published by the International Energy Agency, the average electricity consumption in Australian private homes was 59,353 gigawatt-hours in 2009. This means that each household consumed on average 7.07 megawatt-hours (7,070 kilowatt-hours). The biggest percentage of energy is used for heating and cooling (38%) as well as water heating (25%). Power used for cooking, lighting, fridges and stand-by power makes up 21% of the average Australian household energy consumption[ii]. On average a household of four people uses between 8,700 and 11,200 kilowatt-hours of electricity per year, while a household of six or more people consumes up to 15,000 kilowatt-hours each year[iii]. Of course these figures are averages: how much energy you actually require depends on how many people live in your home, what fuels are used, your home appliances' and building's energy efficiency[iv], and the habits of householders.

Which solar PV system do you need for your family?

The output of a solar PV system depends on the energy generating capacity of the solar panel, that is, how many kilowatts it can generate. In addition, your location in Australia will determine the intensity of sunlight[v], which will impact the amount of energy your panels can supply. The highest annual average sun radiation can be found in the north-western part of Australia, the lowest in the very south[vi].

The most common household PV solar systems are 1 kilowatt or 1.5 kilowatts, producing from 3.9 to 5.85 kilowatt-hours per day in Sydney to 5.0 to 7.5 kilowatt-hours per day in Alice Springs, respectively[vii]. A four person household in Sydney that consumes on average 9,000 kilowatt-hours per year - about 25 kilowatt-hours per day - would require a 1 kilowatt PV system in order to displace 15.6% of their average electricity bill. A 4 kilowatt system could cover up to 62.4%, and a 6.5 kilowatt system would cover 100% of this four person household's electricity consumption[viii].

A solar system is generally made up of a number of panels, as explained in our guide to how solar energy works . The actual number of panels to get to your required energy output will depend on the rating of each panel. High efficiency multi-crystalline panels used by AGL currently are available up to 250 watt. A 1 kilowatt system will require four 250 watt panels.

As you can see from the information given above, the size and number of PV panels you require to generate clean solar electricity for your family depends on several factors. Have a look at your current electricity bill to find out how much power your household consumes, break it down to daily usage, and think about how much of your energy consumption you would like to come from solar energy. With this information, you can figure out which solar panel system you require and how many panels should be installed to reach your target.



[i] Clean energy Australia Report 2011, p. 32

[ii] South Australian Government, How energy is used in the home, http://www.sa.gov.au/subject/Water,+energy+and+environment/Energy/Energy+efficiency/Home+energy+efficiency/How+energy+is+used+in+the+home

[iii] South Australian Government, How energy is used in the home, http://www.sa.gov.au/subject/Water,+energy+and+environment/Energy/Energy+efficiency/Home+energy+efficiency/How+energy+is+used+in+the+home

[iv] South Australian Government, How energy is used in the home, http://www.sa.gov.au/subject/Water,+energy+and+environment/Energy/Energy+efficiency/Home+energy+efficiency/How+energy+is+used+in+the+home

[v] Clean Energy Council, Consumer guide to buying household solar panels (photovoltaic panels), http://www.cleanenergycouncil.org.au/resourcecentre/Consumer-Info/solarPV-guide.html, p.4

[vi] Australian Government, Department of Resources, Energy and Tourism, Energy in Australia 2011, p. 34

[vii] Clean Energy Council, Consumer guide to buying household solar panels (photovoltaic panels), http://www.cleanenergycouncil.org.au/resourcecentre/Consumer-Info/solarPV-guide.html, p.4

[viii] Clean Energy Council, Consumer guide to buying household solar panels (photovoltaic panels), http://www.cleanenergycouncil.org.au/resourcecentre/Consumer-Info/solarPV-guide.html, p.4