Frequently asked questions
Here at CHOICE there are some questions we get asked all the time when it comes to solar PV installations. We put those questions to Damien Moyse from the ATA.
Q: Is now a good time to install solar power?
A: Yes. The payback times in all the states and territories are pretty good now, mainly because the technology is so cheap at the moment. It’s hard to imagine it can stay at this level as it’s not much above the cost price of the gear and the labour costs.
Q: Why do the payback times promised by installers end up being inaccurate?
A: A payback time’s calculation is complex, with 15 or more different variables and no consumer system is the same. When you see a quoted claim by a supplier it’s based on the supplier’s assumptions, which may be different to your reality. The best thing to do is get your energy consumption data for as long a period as you can – ideally longer than 12 months – and think really hard about when you use electricity in your house, and make a calculation based on your individual numbers. Visit the ATA for a calculator.
Q: Can suppliers be held to their payback times promises?
A: Most suppliers will give you a range for the amount your electricity bill will go down, and have disclaimers on their websites or in their terms and conditions saying you need to get specific financial advice for how it will affect your property, and that these are just generic estimates.
Q: Is bigger better?
A: No. You need to understand how much electricity you use in your home between roughly 9am and 5pm (when your PV system is generating at its peak) and match the size of your system to that consumption pattern. If you don’t consume much energy during the day then you’ll want a smaller system that just feeds your fridge. If you have a family at home during the day, you’ll need a bigger system.
Nowadays you don’t get much money back from feeding electricity back into the grid, and you actually pay more for the electricity you use than you get in FiT. So you want to maximise your own usage of your solar PV, and minimise your export into the grid. That’s why exporting less to the grid shortens your payback times.
Q: Is there an environmental reason to export energy into the grid?
A: The best thing to do is reduce your electricity use as much as possible and then produce the electricity you need from a renewable source. There’s still an environmental cost to making solar cells.
Q: Are there any particularly good or bad brands out there?
A: A brand will have models that are good and others that aren’t. You can tell a decent piece of equipment by the warranty a manufacturer is willing to offer. Panels are really quite simple technology, so you should get a 25-year warranty with 80% level of output in the 25th year. The inverters are more critical: if you have a poor inverter you may have a lot of losses through the system, and you don’t want to replace your inverter early. A 10-year warranty for that should ensure you’ll get a decent-quality system.
There is no credence to the anti-Chinese solar PV bias. It’s really too simplistic to say Chinese stuff is bad. Look at the specifications and performance data sheets, and look at the warranties being offered. If they’re only offering a two- or three-year warranty, it’s pretty clear that it’s a cheaply made product that might have a high failure rate.
Q: Are prices going to come down even more?
A: Grid-connected solar systems are unlikely to cost any less than they are now. The predictions are that over the next couple of years solar prices will go up.