University of NSW Professor and solar legend Martin Green has just won the 2018 Global Energy Prize. He shared the honours, and $820,000, with Russian thermal power engineering expert Sergey Alekseenko. Of special note, the two beat out fellow finalist Elon Musk (and 43 other finalists from 14 countries) for the gong.
Professor Green is affectionately known in energy circles as Australia’s “father of PV”. PV being Photovoltaics, which refers to the conversion of sunlight into electricity thanks to the photovoltaic effect.
PV systems are commonplace in Australia. They typically consist of solar panels (made up of numerous solar cells), which convert sunlight to electricity. An inverter changes this current from Direct Current (DC) to Alternating Current (AC). (Homes and businesses use AC current.) Add some mounting hardware, electrical cabling and a few other accessories, and you’re generating power.
The man who brought solar power to the people
For the man credited with bringing solar to the masses to go by “Green” is perfect. According to UNSW (University of New South Wales), Green revolutionised both the efficiency and cost of solar PV. Making it the most cost-effective option readily available today.
Professor Green constructed his first silicon solar cell at the age of 23, while still a student. That was 1971. By 1978 he was assisting with the design of Australia’s first photovoltaic solar deployment. This project provided power to Telecom relay towers in the Northern Territory. Those cells had an efficiency of about 8%.
By 1989, Green and his UNSW team had designed a silicon cell which boasted 20% efficiency. This was a world-record at the time.
Twenty-five years later, in 2014, he led a team who doubled this — recording an energy conversion efficiency of 40% — again a world-record.
The PERCs of solar
The PERC solar cell is another of Professor Green’s inventions. PERC stands for Passivated Emitter Rear Contact, and it’s a stroke of genius. One problem with PV cells, is that they don’t absorb all the sunlight that hits them. Green thought to add an extra reflective layer to the rear of each cell. This redirects unabsorbed light back into the solar cell for a second attempt at conversion to electricity.
By the end of 2017, virtually one quarter of the silicon cells manufactured globally were PERC cells. That’s a big stat, and probably enough to deserve a Global Energy Prize on its own.
But our bet is there’s more to come, as Professor Green continues to head up the Australian Centre for Advanced Photovoltaics at UNSW.
The rise and rise of solar PV
Photovoltaic solar is a near-perfect energy source. Beyond manufacture and installation, its actual operation generates zero greenhouse gas emissions. The main material used in solar PV cells is silicon. And the Earth’s crust has an abundance of readily-available silicon. This makes solar PV a scalable solution for the world’s energy demands.
On the downside, for solar PV to produce electricity, the cells must be exposed to direct sunlight. When solar panels are fixed in place, it’s estimated that between 10-25% efficiency is lost even when the sky is free of clouds, as the angle of the sun on the solar cells changes throughout the day. This problem can be overcome with a tracking system, which moves the solar panels to follow the sun, but it adds cost.
Ultimately, however, the overall cost of solar PV continues to fall by about 5% each year, and once again we have Martin Green and his UNSW research group to thank. Green is quick to pass credit to Stuart Wenham AKA the “Einstein” of the solar world. Sadly, Stuart Wenham passed away in December 2017, aged just 60, but not before completing critical work setting up manufacturing centres in Asia.
In a recent interview, Green told Renew Economy, “In particular, Stuart created this computer program that was a virtual production line, that overcame the language barrier in training hoards of Chinese engineers in setting up these (solar PV) production lines.”
When collecting the Global Energy Prize, Green also acknowledged former-UNSW colleague Zhengrong Shi, who became the world’s first solar billionaire after founding Suntech Power in the US.
He said, Shi said
Zhengrong Shi’s story is another fascinating one. When his company, Suntech Power listed on the NY stock exchange, he became an overnight billionaire and became known as the “Sun King”.
He went on to see his personal fortune rise as high as $3 billion. But when the bubble burst, Suntech Power were overcommitted, and the company were forced into bankruptcy.
Shi seems to maintain a neutral attitude to what can only be described as a rollercoaster ride of fortunes. The Sydney Morning Herald has quoted him as saying, “I was a pure scientist and for 14 years, an entrepreneur running a multi-billion dollar company. It was a good experience.”
Martin Green has a similarly modest attitude to his latest achievement. He says Tesla’s Elon Musk was his pick for the Global Energy Prize, for putting electric cars on the agenda.
The future of solar, according to its father
Even Professor Green probably couldn’t have predicted the global success of solar, now the cheapest form of renewable energy generation on the planet.
Green says, “If you look at the figures from the last few years, growth has consistently stayed at around 40% a year”.
“If it keeps growing at that rate, we’re looking at hitting a terawatt of solar production in 2024.”
Bulk Energy contacted Professor Green directly to clarify the above statements, and received a fast and friendly response. One “terawatt of solar production” is a global total figure, and refers to capacity. That is, peak rating, not average capacity. Here’s the maths:
In 2017 global solar production capacity stood at approximately 0.1TW.
Factoring in 40% growth (1.40), the equation works out to:
0.1 x (1.40)7 = 1.05TW, where 7 is the number of years.
Finally, 2017 + 7 years = 2024.
Professor Green also commented, “This 10x multiplication has happened over the last three seven-year periods.” So there’s a long precedent for his prediction.
On the home front, we can look at it another way: Solar PV was responsible for 2.4% of total Australian electricity generation in 2014-15. (This is as per the Department of Industry, Innovation and Science’s ‘Australian Energy Update 2016’.)
Global Energy Prize helps get the message to governments
At a terawatt, or more, “that’s the area where you can really start cutting greenhouse gases”, says Professor Green, who looks forward to a transition to renewable energy that ends up saving businesses money.
Based on the numbers above, “This would reduce CO2 emissions by circa 1.5Gt/y”. And this is a figure that would make a real difference.
“I think [this is] a good opportunity to get across the message that things have changed with solar and that it’s the best option out there,” Green says. “That’s an important message to get out. There’s a growing consensus that we’re going to get most of our energy out of solar down the track.”
Awards like the Global Energy Prize can only help get the message out to governments and energy consumers.
Bulk Energy are onboard. We’re currently in the final stages of preparing to launch a variety of solar options for our customers — watch this space…