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
What size system will meet my needs?
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 (eg. morning), you can then find out what size solar PV system you need.
How much money will I need to spend?
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.
How important is panel efficiency?
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.
What are solar panels made from and is one type better than the other?
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 25year 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.
Why is a particular system being recommended to me?
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.
How do I know whether the system I’m offered is a good one?
One way to check if your solar PV system components meet Australian Standards is on the Clean Energy Council’s Products webpage. 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.
What Government schemes apply?
There are two financial schemes open to you when buying a solar PV system. The Australian Government offers the Small-scale Renewable Energy Scheme, where you are issued with tradable certificates for eligible solar PV systems.
The second scheme is the Queensland Government’s regional feed-in tariff for regional Queenslanders. It requires electricity retailers to pay eligible customers a feed-in tariff for electricity generated and exported to the grid from their solar PV system.
Remember - To be eligible for Government schemes, one condition is that your system must be installed by a CEC accredited installer.
Please note: the Solar Bonus Scheme 44 cent feed-in tariff rate is closed to new customers.
Are you an accredited installer?
It’s important to choose a solar PV installer who is accredited under the Clean Energy Council (CEC). You can find an installer who is accredited in your local area or check whether your chosen installer is accredited.
Will the company quoting on the system also be doing the installation?
Some installation companies have teams of their own installers who are trained by them and work only for them. Others may use sub-contractors who work for several different installation companies. Just because an installation company uses sub-contractors does not mean the quality of work is lower.
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.
Does shade affect a solar PV system?
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, eg. 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.
What racking (mounting) will be used and what is the warranty?
Standard racking components are usually the rail itself (anodised aluminum) 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.
Does the racking use both mid and end clamps to secure the panels?
The most commonly used option is to drill into the frame-work. 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
How will the system be maintained?
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.
Are manufacturer warranties supported locally and how are warranty claims handled? What happens if something goes wrong with the PV system?