In 2012 solar consultancy SunWiz looked at data from 8,000 PV systems connected to NSW network AusGrid and found the average small-scale system was performing nearly 19% below capacity, with around 18% of systems performing 20% below expectations and 7% about 40% below expectations.
That was six years ago and here’s hoping things have improved since then, but system owners shouldn’t be complacent about their investment. Maintenance of a solar PV system is about so much more than cleaning the modules.
“System maintenance is crucial to the ongoing optimised performance of the system – if you want it to go well, you’ve got to look after it,” says Solar Analytics technical sales account manager Brett Bidwell.
The basics of maintenance include looking at the performance of the inverter and going over the solar array structure, the cabling and assessing whether anything has contributed to the system performing properly. The causes are not always related to sloppy installation standards or cheap equipment.
“Over the years I’ve seen ants, termites, possums, cockatoos, rats – you name it I’ve seen it destroy a solar power system,” says Bidwell. “Cows, horses, sheep – the whole lot. I’ve seen bats roosting under arrays, all sorts of things.”
Many variables that are completely unforeseen and unpredictable may impact the performance of a system, Bidwell says, so owners should understand why an annual inspection by a qualified solar installer – even it is to clean the panels – will be a good way to spot and fix issues that could become serious if left to fester. “There are opportunities there for maintenance to be discussed [with owners] very early on in the piece, even before the purchase of the system,” he says, emphasising that solar sales companies and installation companies should clearly explain the benefits of maintenance to their clients.
Installers are working all hours to get systems on rooftops, with record numbers of Small-scale Technology Certificates created last year and hopefully the same again this year, so how can they be expected to find the time to go around maintaining the 1.6 million systems already in place? Simple, says Bidwell – employ more people.
For a start, installers who have contractual commitments to maintain systems should manage schedules and staff especially for the purpose. “Suddenly you’ve got a crew running around doing regular maintenance,” he says. “Quite often the return on investment of those types of funding approaches is completely dependent on the optimised performance of the system, so that if it works better you get paid more.”
Any good commercial and industrial solar system agreement should include a clause about operations and maintenance, Bidwell says. “It’s not an option. If it’s not there, you’re dealing with the wrong people.”
At the Clean Energy Council, technical and compliance officer Luke Pickles says it’s not really incumbent on the installer to carry out maintenance – it’s up to customers to request it. “The problem is there’s a cost associated with doing maintenance and people normally buy a solar system with the purpose of saving money, so there’s a disconnect in that respect,” Pickles says. “But some companies that sell a system may include a maintenance visit as part of the sale price.”