Australia’s rooftop solar market is expected to add almost 3 GW of new installations in 2020, but Enphase Energy has warned that there are risks associated with enormous uptake.

The California-based company's Comparison of Australian and US Residential Solar Markets report reveals that Australia has had to deal with a growing number of solar-related fires in recent years. Figures provided by the NSW Fire Brigades’ Fire Investigation and Research Unit show that “solar-related fires in that state have increased five-fold over the last five years.”

Enphase Energy points the finger squarely at Standards Australia’s mandated use of DC isolators for PV systems with string inverters. The report warns that DC isolators – intended as a safety mechanism to disable dangerous high-voltage DC between the solar array and inverter – “can easily degrade and malfunction” and have “become a common cause for solar-system fires.”

That declaration is backed by a survey of Australian PV installers, commissioned by not-for-profit organization Renew. The survey showed that more than 60% of installers say that rooftop DC isolators are the primary cause of solar-related fires.

“In (New South Wales) alone, there is a 20% increase in fires related to solar panels since last year, with more than 50% caused by DC isolators. Since they are connected to high-voltage systems, DC isolators also pose an electrocution risk for maintenance or emergency personnel,” Enphase Energy said.

In the United States, requirements for solar-system safety have been added into state and municipal electrical, building, and fire codes, as well as permitting and inspection processes. All installers must follow National Electric Code (NEC) guidelines, which include strict requirements on rapid shutdown capabilities to automatically lower voltages and de-energize solar modules in the event of an outage or fire.

Enphase Energy said Australia is the only country that requires DC isolators to be installed. But it noted that the regulation is currently under reconsideration, with recalls of several brands of DC isolators due to fire safety concerns.

“While Australia’s regulations may lag behind its global counterparts, state and federal authorities are actively working to address this issue,” Enphase Energy said.

The Clean Energy Council (CEC) is among those advocating for a rule change. A recent CER report identified water ingress in DC isolators is the biggest safety risk associated with rooftop PV. The CEC has said that including the DC isolator inside the inverter, rather than as a separate switch near the inverter, is the best solution.

This article is reproduced at www.pv-magazine.com