Australia's solar scientists make breakthrough in quest for low-cost panels
Solar power is a hot topic in Southeast Asia. ASEAN nations are pursuing policies to diversify their energy sources and have set a target to source 23 per cent of their energy from renewables by 2025. To support this goal, ASEAN Member States are developing energy initiatives in solar and bio-fuels programs, and promoting open trade and cooperation in the renewable energy sector.
As a recognised world leader in solar cell research, Australian science has the capacity to power this renewables revolution in Southeast Asia. Australian scientists have been at the forefront of research into photovoltaic cells for 40 years. Between them, the University of New South Wales (UNSW) and the Australian National University (ANU) have broken 14 world records in solar cell efficiency.
One of Australia's leading research organisations is the Australian Centre for Advanced Photovoltaics (ACAP). Based at UNSW in Sydney, ACAP has established a strong track record for licensing solar cell technologies to manufacturers around the world. It includes researchers from the University of Queensland, Monash University, ANU, the University of Melbourne and CSIRO.
Today, the ACAP team is leading research that could dramatically reduce the cost and complexity of making solar panels. In December 2016, ACAP announced a world record efficiency for a certified solar cell larger than 10cm2 using a specific type of structured compound, called a perovskite. According to Anita Ho-Baillie, Senior Research Fellow at the School of Photovoltaic and Renewable Energy Engineering, and Program Manager for the Perovskite Solar Cell Research at ACAP, perovskites are the fastest-advancing solar technology to date.
'Existing silicon-crystal solar panels are expensive to make, partly because they have to be baked at almost 1,000 degrees centigrade,' she says. 'Perovskites are highly versatile, and because they exist in solution, we can paint, spray or print them onto solar cells. The actual photovoltaic cell layer is just 500 nanometres thick, which is five hundred times thinner than a silicon solar cell.'
By making solar cells simpler and cheaper to make, the new perovskite technique could shake up global manufacturing of solar panels. This could have a major impact on the uptake rate of domestic solar power in Southeast Asia.
Researchers still have some way to go before the technology can be licensed. Besides the never-ending quest for greater efficiency, the team is looking for ways to make a perovskite cell film more durable, so it can withstand fluctuations in temperature and moisture levels. Nevertheless, Ho-Baillie believes the technology could gain interest in Southeast Asia for climatic reasons.
'In Australia, we have lots of direct sunlight, and these are the conditions in which silicon-based photovoltaic cells work most efficiently,' she says. 'However, where there is frequent or intermittent cloud cover, then light is more frequently diffused and silicon works less well. This gives perovskite solar cells an advantage which suffers less in diffuse sunlight conditions.'
Ho-Baillie's team is now tackling some of the commercialisation issues associated with perovskite solar cells, while also increasing efficiency to levels comparable to silicon cell panels which currently dominate the world market. Recently UNSW has teamed up with Nanyang Technological University (NTU), to build a world-class joint facility with the aim of rejuvenating degraded silicon solar cells so that they won't suffer performance degradation over their lifespan, which is typically 25 years. This technology has been developed at UNSW led by UNSW's Professor Stuart Wenham and Associate Professor Chong Chee Mun. NTU's Adjunct Associate Professor Matthew Tan has teamed up with UNSW to take the technology to Singapore to commercialise it. Their plant is a joint collaboration between solar technology development firm CEC Energy, NTU and UNSW.