Learn About Solar Power
How does solar PV work?
Solar Photovoltaic (PV) panels are generally fitted on the roof in a northerly direction (east or west is also possible with some trade off’s) and at an angle to maximise the amount of sunlight that hits the panels. Solar panels are different to solar hot water systems, which are also mounted on household roof‐tops but use the heat from the sun to provide hot water for household uses.
Solar Photovoltaic (PV) panels on the roofs of homes and businesses generate clean electricity by converting the energy in sunlight. This conversion takes place within modules of specially fabricated materials that make up the solar panels. It is a relatively simple process that requires no moving parts. In most cases solar panels are connected to the mains power supply through a device called an inverter.
The technology to convert sunlight into electricity was developed in the 19th century, but it was only in the second half of the 20th century that development accelerated behind the need to provide reliable supplies of electricity in remote locations – from satellites in space to outback Australia.
Solar panels have been installed on the rooftops of houses and other buildings in Australia since the 1970s. Currently there are more than 100,000 solar panel systems safely and reliably delivering clean electricity across Australia.
Increased scale and development of the technology in the early 21st century has seen the cost of solar panels continue to fall, making them more affordable. Over the past decade there have also been changes to government programs to help households reduce their greenhouse emissions and cut power bills. Expanded use of affordable and reliable solar panels will help reduce Australia’s greenhouse emissions and provide a clean and distributed source of energy across our towns and cities.
Source: Clean Energy Council Australia
Grid‐connected solar PV systems
Most suburban homes in Australia are connected to the electricity grid, which uses alternating current electricity (AC). But the electricity generated by solar panels is direct current. That means grid‐connected (GC) solar PV systems need an inverter to transform the DC electricity into alternating current (AC) electricity suitable for ordinary household needs. The existing electrical panel distributes solar electricity firstly, and utility power secondly, to household appliances.
When the panels are not producing electricity at night, electricity is supplied from the existing electricity grid. For systems with a battery backup (optional), the inverter regulates the charge of batteries. The electricity stored in the batteries can be used at night or during blackouts.
The existing electrical meter measures your total electricity consumption and production. If your solar panels produce more electricity than you consume, you can sell the excess electricity back to your electricity retailer. This is known as a feed‐in tariff agreement and is discussed in further detail below.
Source: Clean Energy Council Australia
How much power will my system generate?
The output of a solar PV system depends on its size. The most common household systems are either 1 kilowatt or 1.5 kilowatts, although some property owners have installed systems of up to 10 kilowatts. The table below shows the average daily production of some common grid‐connected systems throughout Australia.
Average Daily Production
| City | 1 kW system | 1.5 kW system | 2.0 kW system |
|---|---|---|---|
| Adelaide | 4.30 kWh | 6.45 kWh | 8.60 kWh |
| Alice Springs | 4.56 kWh | 6.84 kWh | 9.12 kWh |
| Brisbane | 3.86 kWh | 5.79 kWh | 7.72 kWh |
| Cairns | 3.70 kWh | 5.55 kWh | 7.40 kWh |
| Canberra | 3.97 kWh | 5.95 kWh | 7.94 kWh |
| Darwin | 4.30 kWh | 6.45 kWh | 8.60 kWh |
| Hobart | 3.24 kWh | 4.86 kWh | 6.48 kWh |
| Melbourne | 3.38 kWh | 5.07 kWh | 6.76 kWh |
| Perth | 3.71 kWh | 5.56 kWh | 7.42 kWh |
| Sydney | 4.00 kWh | 6.00 kWh | 8.00 kWh |
PV‐GC spreadsheet based on the CEC GC Design Guidelines .
PV Array 1kWp facing true north and a tilt angle of 20° with an average inverter / wiring efficiency – 0.92, using long term average solar irradiation and temperature data from the Australian Solar Radiation Data Handbook.
A typical Australian house consumes around 18 kilowatt hours per day so a 1‐2 kW system displaces an average of 25‐50% of your average electricity bill. Solar panels produce more energy in summer than they do in winter.
Source: Clean Energy Council Australia
How much do solar panels cost ?
The cost of solar panels has continued to change over the past decade behind different government incentive schemes and increased diversity in the panels, inverters and suppliers in the market.
Being an informed consumer is increasingly important. Similar to buying a car or a computer, you’ll want to be sure that your system is a sound investment that best meets your needs at a reasonable price.
It is important to be clear on what you want from your solar PV system. Are you after a system that will partially offset your energy consumption for 5‐10 years before requiring a system upgrade? Or do you want a system that will completely offset your household’s electricity use for the next 25 years?
Like buying a second‐hand car as opposed to a brand‐new sports car, these two solar PV systems are both sound investments depending on your needs, but will vary significantly in price.
The price of your solar PV system can also be affected by variables including:
- Location
- Number of panels
- Orientation of panels
- Type of panels
- Type of inverter
- System design and configuration
- Shipping costs for equipment and parts
- Contractor installation costs
- Removal of trees or other shading
- Site preparation needs (for example, condition of roof or ground)
- Structural engineering, architectural, and other professional services (for commercial systems)
It is also important to note that if you have a solar PV system installed, your electricity rates will change from an off‐peak tariff to a time‐of‐use (TOU) tariff. This will particularly affect your dedicated off‐peak loads, such as hot water, space heating and air‐conditioning. You should check with your electricity retailer whether the benefits of the time‐of‐use (TOU) tariff outweigh the benefits of staying on your off‐peak tariff. This needs to be considered before your install your solar PV panels.
Source: Clean Energy Council Australia
