Solar panels on the roof of a house

Important questions to ask

When you are talking to an accredited solar retailer or installer, here’s a few questions to ask to help you make the best decisions.

Choosing a system

Before you decide to go solar, it is very important to know how much electricity you use and at what times of the day. You can find your usage in kilowatt hours (kWh) on your electricity bill. If you cannot find it, contact your electricity retailer.

Once you know your energy usage and you are aware when the most is used (e.g. morning), you can then find out what size solar PV system you need.

Your reasons for installing a solar PV system will help determine how much you spend. You may wish to help the environment, or to reduce your annual power bills. How much you will save on your power bills depends on your electricity tariffs, so ensure you consider this. Discuss your reasons with your solar retailer so they can help you decide how much to spend.

Panel efficiency may not be the most important thing for you to worry about. It is more important to consider your system as a whole. The cost and performance of your system will depend not only on the panels you use, but also your solar inverter, your installer’s labour costs, the orientation of your roof, and tilt angle of your panels.

While there are many brands available, there are just three types of technologies involved in making a solar panel – monocrystalline, polycrystalline and amorphous thin film. Here’s a quick overview of their qualities:

  • Monocrystalline – have good power-to-size ratio, outstanding performance in cooler conditions and previously the most commonly used technology in the world, with over 50 years of development. Monocrystalline panels have an excellent life span / longevity and usually come with a 25 year warranty.
  • Polycrystalline – have good efficiency and are generally less expensive to produce than monocrystalline. They have a slightly better performance in hotter conditions and an excellent life span / longevity. They usually come with a 25 year warranty.
  • Amorphous Thin Film – have low conversion efficiency and expected lifespan less than crystalline panels. However, they have the best efficiency in hot weather but are less effective in cooler conditions. They also require 2-3 times more panels and surface area for same output as crystalline. They are ideal for inland Australia, where conditions are hot and vacant space is available.

Remember - the best solar panels for you will depend on your needs and location.

Your solar retailer or installer will discuss with you what system types and sizes are best for your premises, and also what is available in your area in terms of installers, panels and inverters, connections and Government schemes. Then, based on your budget and priorities, they will recommend a solar PV system for you.

Ultimately, the choice is up to you, so make sure you shop around and get a few recommendations and research what schemes may be available to you.

One way to check if your solar PV system components meet Australian Standards is on the Clean Energy Council’s Products web page. Accredited solar retailers and installers should always refer to these lists to ensure they are offering you a system that is of a high standard and will operate safely and reliably.

44c solar feed-in tariff

The 44 cent feed-in tariff (FiT) was closed to new solar customers in July 2012. Existing customers on the 44c FiT may lose eligibility if they make changes such as:

  • close their electricity account, or add someone as an electricity account holder (other than their spouse)
  • increase the rated inverter capacity
  • add panels which increases the array capacity beyond the rated capacity of the existing inverter/s, or
  • add an energy storage system (like a battery) which can discharge at the same time as the PV system (other than during a network outage).

If you are considering changes to your solar PV system, you can discuss these with our Solar Team via email

For more information, visit the Queensland Government’s Solar Bonus Scheme 44c FiT website.

If you believe we have incorrectly removed your 44c/kWh FiT, please complete our Solar Bonus Scheme tariff change form (PDF 44.1 kb).

Remember - To be eligible for Government schemes, one condition is that your system must be installed by a CEC accredited installer.

Small-scale Renewable Energy Scheme

This Australian Government scheme encourages the installation of solar water heaters, heat pumps, and small-scale solar PV (up to 100kW), wind and hydro systems by issuing buyers with Small-scale Technology Certificates (STCs).

STCs are an electronic form of money and are allocated to you when you install an eligible system. You get one certificate per megawatt hour of electricity calculated to be generated by your solar PV system up until 2030. That is, the number of STCs your system is eligible for will decrease each year.

STCs have to be created within 12 months of your system being installed.

There are two ways to cash-in your certificates:

  1. You can create and sell your STCs yourself. Wholesale buyers of electricity (mainly electricity retailers) purchase STCs to help them meet their renewable energy targets. The price they pay per certificate depends on market supply and demand at the time. STC trading is done online via the Renewable Energy Certificate (REC) Registry, and their REC calculator helps you estimate how many STCs your proposed solar PV system will earn.
  2. You can assign your STCs to a registered agent. Registered agents are usually solar retailers or traders who will pay you the market value for your STCs. Solar retailers usually offer an upfront discount off your solar PV system if you assign your STCs to them. This is the most popular option as it’s simpler and faster than trading your STCs yourself.

Learn more on the Clean Energy Regulator’s Claiming small-scale technology certificates web page.

If you are on the 44 cent solar feed-in tariff (FiT) and you make a change to the name on your electricity account, or increase the capacity of your inverter, you may lose your eligibility for this rate.

More details are available on the Queensland Government Solar Bonus Scheme web page.

If you believe we have incorrectly removed your 44c/kWh FiT, please complete our Solar Bonus Scheme tariff change form (PDF 44.1 kb).

Please note: the Solar Bonus Scheme 44 cent feed-in tariff rate is closed to new customers.


In Queensland, solar panels should face north to receive the most sunlight over the year. But if your only options are east or west, or even south, which should you choose?

West facing panels will generate electricity until later in the day, so this could suit you if you use the most power in the afternoon. East facing panels may be best for you if you use the most electricity in the morning. A combination of east and west facing may even be ideal.

South facing panels won’t generate as much electricity as those facing other directions. Adding more panels can compensate for this lower efficiency if this direction is your only option.

It’s best to discuss the orientation options available to you with your solar retailer or installer.

Shade could have a big impact on the output of your system. In a solar panel array, shade reduces the flow of solar power through the panels. Even if shading is on just one of the cells within a panel, e.g. from bird droppings, the output of the entire array will be reduced while the shadow is there.

It’s therefore important to check if your roof is shaded by nearby objects at any time of the day and year. Your solar panel array should be positioned away from any shade for the best efficiency.

You may have the option of splitting your solar array across a roof which faces different directions. For this kind of set-up, you should install an inverter that can accept multiple inputs for the best results.

Many modern panels come equipped with devices called bypass diodes. These devices reduce the effects of partial shading by enabling solar power to ‘flow around’ the shaded area. There are even panels that are designed to operate effectively in part shade.

Be sure to discuss this with your solar retailer or installer if shade may be a problem for you.

Standard racking components are usually the rail itself (anodised aluminium) and fasteners (stainless steel). The rail is made up of various clamps, plates and brackets. The racking warranty is included in the installer's warranty and should be located within the installers’ terms & conditions.

As this is an important part of the system, especially for high wind areas, ask your installer for specific details about the racking that they use.

The most commonly used option is to drill into the framework. However, mid-clamps can provide a more stable installation, so it is worth asking your installer if they use them. If you are told that they will cost extra, ask how much extra and for them to justify the cost. Some installers will use mid-clamps as standard, while others will view it as an optional extra.

Maintenance and warranty

Your installer should provide you with a maintenance schedule to ensure your new solar panels last up to 25 or even 30 years. Your inverter will need to be replaced at least once in that time.

There is very little maintenance with a grid-connected solar PV system. All you need to do is keep the panels clear of debris and dirt, and have the electrical system and wiring inspected by a licensed electrical contractor periodically.

There is also a range of system monitoring devices available that you can ask your solar retailer about.

As with any large purchase, it’s important to check who holds the warranties on the solar panels and inverters. Australian Competition and Consumer Commission rules also apply to solar PV system purchases.

An independent publisher, EcoGeneration, has released a guide for installers and retailers on warranties and insurances where you can check the relevant policies for most major brands.