The debate over Australia’s energy crisis is heating up. Whatever the political outcome may be, one thing seems certain – the use of large-scale and residential solar is moving forward swiftly.
The majority of large-scale solar investment is occurring in Queensland, with 21 solar farms producing more than 1,300MW of renewable energy, worth $2.6 billion. There are an additional 13 new solar farms in the pipeline.
FM Global believes that this solar boom is at risk. In stark contrast to the large level of investment in solar, there’s very limited construction guidance on how to build solar farms that stand up to cyclones.
At present, Australia follows European Standards to test solar PV. These tests are not appropriate for the Australian environment because they assess the strength of the PV panels using a static load which is more representative of a snow load and does not replicate the dynamics of wind loads generated by tropical cyclones. This is despite the fact there have been 47 tropical cyclones in Australia since 2010, bringing gales, heavy rain and storm surges.
Caution – and regulation – needed
FM Global strongly believes that national standardised testing of solar panel resilience needs to be regulated by law. This testing should encompass a solar panels’ ability to physically withstand the impact of a cyclone and to continue to produce electricity afterwards.
Fortunately, we’re now closer than we’ve ever been to knowing what that testing might look like. We recently worked with Sun Metals Corporation, in the Townsville region, to test the resilience of its solar farm, the largest behind-the-meter solar farm in Australia (124MW). The solar farm covers up to 120 hectares and includes more than a million ground-mounted solar panels connected to an existing 33/132kV substation.
Over four months in early 2018 we worked with James Cook University’s cyclone testing station to develop an appropriate testing protocol for the fixed-tilt, ground-mounted solar panels. The plan was to determine the failure mode of the entire structural system; such as, whether the framework would buckle, if the panels would crack and how their electricity output would be affected if the panels were subjected to cyclonic winds.
Using the existing wind-tunnel data from the solar farm project to estimate wind loads on the panels and conducting scoping static tests to estimate the overall strength of the structural system, we were able to simulate a tropical cyclone with an equivalent wind speed of over 250km/h. The test applied this pressure to the panels 10,000 times to simulate the passing of a devastating cyclonic storm.
The results? The panels cracked at the clamps, but still produced electricity, allowing the issue of the cracked clamps to be addressed before an actual cyclone strikes. This test enabled FM Global to have a clear picture of the potential risk involved.
Because most large-scale solar farm projects are of bespoke design to best utilise the topography of the site and the needs of the owner, FM Global recommends that each solar farm project undergo testing to determine whether the solar farm can withstand the impact of a cyclone.
More work to be done
While this is a step forward, and a great reassurance for both FM Global and Sun Metals, there is much more work to be done. FM Global believes the Australian government should develop and create testing protocols for the full variety of panels and mounting configurations in use, since the current standards seem to be out of step with the appetite for solar investment.
Installers, as key stakeholders in this sector, could have a great impact in the implementation of such regulations. Doing so can only help build further confidence in the ability of solar to transform the economy and cut costs for consumers.
Without such building regulations, the disruptive impact of cyclonic damage to the industry, consumers and businesses has the potential to get bigger as the demand for solar power increases in Queensland. Let’s not wait for a catastrophe to act.
Terence Lee is senior account engineer at FM Global.