Australian solar pioneers win prestigious energy prize

The 2023 Queen Elizabeth Prize for Engineering (QEPrize) has been awarded to four Australian solar researchers for their work to develop Passivated Emitter and Rear Cell (PERC) solar photovoltaic technology. This work, developed at UNSW Sydney, has underpinned recent exponential growth in high-performance, low-cost solar electricity.

Celebrating its 10th year in 2023, the prize is presented annually to engineers responsible for innovations that have been of global benefit to humanity. The IREG List of International Academic Awards regards it as one of the world’s top awards, with a reputation score of 0.51 compared to a Nobel Prize. The 2023 prize has been awarded to Prof Martin Green (UNSW), Prof Andrew Blakers (ANU) and solar entrepreneurs Dr Aihua Wang and Dr Jianhua Zhao.

Lord Browne of Madingley, Chairman of the QEPrize Foundation, announced the winners in London. The 2023 Laureates improved the energy conversion efficiency of commercially dominant silicon cells by improving the quality of the top and rear surface of standard silicon solar cells.

When sunlight — in the form of particles called photons — enters a cell, it excites the electrons within the silicon. In this excited state, electrons can move through the cell, creating electric current. The improved surface of the PERC cell allows the electrons to maintain this excited state — or move freely — for longer, resulting in greater and more efficient energy generation.

In 1983, Green and Blakers produced solar cells with 18% efficiency at UNSW, surpassing the 16.5% recorded previously. Over the next two years, they raised the efficiency to 20%, and achieved 21% efficiency in 1988 with Wang and Zhao. Green had theoretically determined the maximum achievable efficiency to be close to 30%. In 1999, led by Wang and Zhao, this was achieved.

Green’s lab at UNSW held the record for efficiency for 30 of the 40 years between 1983 and 2023.

“As engineers, we are constantly striving to improve the world we live in. As the world feels the devastating impacts of our changing environment and collapsing ecosystems, I feel passionately that we must rapidly reduce our reliance on fossil fuels if we wish to maintain the trajectory of human civilisation on our shared planet. I hope that PERC technology winning the QEPrize will highlight the importance of accelerated solar adoption to address climate change,” Green said.

The awardees published their findings without patenting after recognising the significant role PERC technology plays in the development of solar energy, to encourage further developments within the field and drive down the cost of production.

“This has not only been in developing new cell technologies like PERC, but also in transforming the solar manufacturing industry by using their expertise to establish manufacturing in low-cost regions of Asia. This is one of the main reasons that solar has suddenly become so cheap over the last decade,” Green said.

In 2006, Wang and Zhao set up China’s second large-scale solar manufacturer, Chia Sunergy. The first was established by another of Green’s students, Zhengrong Shi.

With the cost of solar power generation falling by over 80% in the past decade, PERC technology is the most commercially viable silicon solar cell technology used in solar panels and large-scale electricity production, accounting for almost 90% of the solar cell market globally.

Blakers said he hopes to use his platform as a QEPrize recipient to highlight the importance of accelerated solar adoption to address global warming threats.

“Solar energy is enormously abundant nearly everywhere. Silicon solar cells allow clean and affordable electrification of energy-poor rural areas across Asia, Africa and the Americas,” Blakers said.

As the global solar pathfinder, Australia generates about twice as much solar energy per person compared to any other country. Solar and wind are rapidly displacing coal and gas from the national electricity grid.

“Silicon solar cells provide the cheapest energy source in history. Universal access to very cheap and abundant solar and wind energy allows the elimination of fossil fuels, resulting in an 80% reduction in global greenhouse emissions,” Blakers said.

The QEPrize Laureates will share £500,000 in prize money and will be honoured at a presentation ceremony in London later this year.

Image credit: iStock.com/SimonSkafar