Harness the sun to power your home
Although Melbourne is a bit further south than Brisbane or Sydney, there’s still enough sunshine to make panels a worthwhile investment.
According to PV Watts, a typical Melbourne home’s roof receives about 4.8 kilowatt-hours (kWh) of raw sunshine per square meter per day, BOM.gov.au website averages work out to about 4.18kWh. Essential, this sunlight is the ‘fuel’ for the system. If a solar PV system could be 100% efficient (which is not physically possible), a 1 kilowatt (kW) solar system in Melbourne would produce between 4.18kWh – 4.8kWh of energy per day, and a 2kW system would produce between 8.36kWh – 9.6kWh per day.
In real life, however, there are efficiency losses that must be taken into account between the time the sun hits your panels and when it exits the system’s inverter. The table below shows rough daily energy output figures for a range of popular solar system sizes if installed on a north-facing roof in the Melbourne area, assuming an efficiency loss of about 25% (to be conservative).
|Approx. daily solar PV system yields in
Melbourne (Popular system sizes, at 85% efficiency)
|Solar system size
|Avg daily system output
|1.5kW||4.7kWh – 5.4kWh|
|2kW||6.3kWh – 7.2kWh|
|3kW||9.4kWh – 10.8kWh|
|4kW||12.5kWh – 14.4Wh|
|7kW||21.9kWh – 25.2kWh|
|10kW||31.4kWh – 36kWh|
How solar energy saves you money
When you are grid-connected with no solar system, you have to purchase all of your electricity from an energy retailer. Typically, you will pay at least 21c for every kilowatt-hour that you use.
Having solar panels will allow you to save money by reducing your need to purchase energy from the grid – every unit of solar energy that you ‘self-consume’ in your home is a unit that you do not need to pay for. You can also earn credits (a minimum of 11.3c/kWh from July 2017) for selling your energy into the grid, but you’ll save far more money by focusing on maximising your solar self-consumption.
We happy to help you select a solar PV system size based on the amount of energy that you consume and your consumption pattern: