Professor Martin Green, 75

Scientia Professor at University of New South Wales and director of Australian Centre for Advanced Photovoltaics

Green by name and green by nature, Professor Martin Green’s efforts have paved the way for the use of solar energy the world over. 

In the 1980s, he created a solar cell so powerful and efficient that it became the main ingredient in about 90 per cent of all solar panels manufactured in 2022.

A solar cell his team created in 1983 had an 18 per cent efficiency, surpassing that of other solar cells at the time which were 16.5 per cent efficient, at best.

Efficiency in this case refers to the amount of captured energy from sunlight that is converted into electricity.

In 1988, Prof Green created a type of solar cell called Perc which was 22 per cent efficient.

Perc stands for Passivated Emitter and Rear Cell, and it was created by improving the quality of the top and rear surface of traditional solar cells.

Improving on the device through the 1990s, Prof Green and his team at the University of New South Wales in Australia managed to produce the world’s first 25 per cent efficient solar cell in 1999.

Prof Green’s lab has held the global record for solar cell efficiency for 30 of the 40 years between 1983 and 2023, and he is often called the “father of photovoltaics”.

His invention earned him the 2022 Millennium Technology Prize, which is the Nobel equivalent for engineers.

Prof Green’s background was in microelectronics, but he soon grew disillusioned with the field in the early 1970s as its main application was in consumer products such as TV sets and sound equipment.

“I missed the computer revolution and the Internet, which was several decades into the future. I was looking for something with a bit more social impact,” he said.

“There were the oil embargoes of the early 1970s that increased the interest in new energy sources. So it was a natural for me to move into photovoltaics where I could apply some of the skills that I developed during my microelectronic studies.”

Giving a lecture on his work at the Global Young Scientists Summit at the National University of Singapore on Jan 9, Prof Green noted that areas including the Indonesian archipelago and Singapore are particularly favourable for having floating solar farms out at sea. This is because the equatorial region has calmer seas.

“It just so happens that this region of the world has some of the lowest historic wave heights over the last 40 years. You’re free from tropical storms. And wind speeds are only moderate here, so that means it is less challenging to think about deploying solar (panels) out in the open ocean around Singapore... given the limited land mass,” explained Prof Green.

While installing solar panels in reservoirs and lakes is not an unfamiliar concept, at-sea solar farms are becoming the next frontier in harnessing energy from the sun.

In 2022, it was announced that Keppel’s subsidiary, Keppel Energy Nexus, will be trialling an at-sea floating solar system near Jurong Island and the pilot will generate 1.5 megawatt-peak of power.

In his long career in research, one thing Prof Green has learnt is that one has to get used to failures.

“I’d say for every success we had in exploring a new idea, there’d be nine failures for ideas that we explored before that,” he said.

Perseverance was a theme throughout the four-day summit.

Addressing early-career researchers at the summit, Deputy Prime Minister and Coordinating Minister for Economic Policies Heng Swee Keat said: “While governments can invest in nurturing scientific talent and building the right environment for them to do their best work, what ultimately matters is our young scientists having a collaborative and open-minded outlook, and a spirit of perseverance.”

Mr Heng, who is also chairman of the National Research Foundation which organised the summit, encouraged the young scientists to venture beyond academia and spend time in the industry. “This can be fruitful especially in understanding real-world problems and challenges, so that your research can be even more impactful,” he said.