A Solar Choice broker will help you, at no charge, decide what size solar energy installation best suits your needs and budget. In the meantime, we hope the following article will assist you in making the right decision.
How to calculate the size of solar system for your home
1. Look at your energy bill
The best place to start is by taking a look at your most recent energy bills. Most energy companies have a graph on the back of your bill which sets out your average daily energy consumption. An energy efficient Australian three bedroom home, with an average sized family and reasonable use of air conditioning, will usually have an average daily consumption of around 12kWh to 16kWh.
Now depending on where you are in Australia and how much day light you receive on average per day, a 1kW solar power system will usually produce around 4kWh to 5kWh of energy per day. So the general rule is that a 3kW solar energy installation will usually be enough to cover all the power needs for an energy efficient average Australian home.
If however you live alone, or maybe are a retired elderly couple, your household energy needs will be significantly less. Usually a 2kW solar power installation will cover most if not all of your energy needs.
But a 1kW solar power system can effectively become a 3kW or 4kW system depending on what feed in tariff is offered by your State or Territory, and how much energy you use (see below).
2. Calculate your federal government Solar Credits rebate
The Federal Government issues certificates for each megawatt-hour (MWh) of electricity expected to produced over the course of a solar system’s lifetime (a nominal 15 years, although systems actually typically go on functioning for 25 or 30). For the first 1.5kWh of a system, there is a REC multiplier available.
REC/STCs are sold on a market, and their price fluctuates (initially about $40, but have fallen as low as $18-20.) You can see current prices on the Clean Energy Council website.
3. Determine if you are eligible for a solar feed-in tariff in your state
A solar power feed in tariff, or reward scheme, gives you financial credit for the energy your solar panels feed back into the main grid. (Read about the current state-by-state Solar Feed-in Tariffs.)
For example, if you are at work during the day when the sun is shining and with only your fridge running at home, a 1kW solar power system will be feeding more energy into the grid than what you are using. A calculating device installed at your meter keeps a tally every 30mins throughout the day of this surplus energy, and credits your account. Obviously your solar panels don’t work in darkness, so at night there will be no power from your solar energy system going back into the grid. Every three months your energy company looks at the “for and against” tally, and either issues you a bill or – if you are ahead on the tally – a credit to your account for which you can elect to receive a cheque. Wouldn’t that be nice to receive in the mail from your energy company?!
Read about the different types of Solar Feed-in Tariff and Solar Buyback schemes available in Australia and how to take advantage of them.
How do I get started with solar power?
We hope the above points are helpful to you. Take 30 seconds to complete our online request for a quote comparison, or feel free to give your Solar Choice broker a call on 1300 78 72 73 to further discuss what size installation best suits your budget and energy needs. Remember, you don’t have to pay us anything at any stage. If you accept one of the discount quotes we broker for you, then the installer pays us a small commission on the value of the installation.
Written by Angus Gemmell
Managing director, Solar Choice