(Published - 26 November 2019)
Meeting the world’s energy needs is a big challenge, but the solution may just lie in some small science: nanoscience.
“Energy consumption is rapidly increasing worldwide - and that, along with extreme exponential growth in the world’s population, is resulting in a variety of challenges: global climate change; slowing economic growth; a lack of access to electricity for many people,” said Professor Ruud Schropp, Extraordinary Professor in Physics at the University of the Western Cape. “We need to meet our increasing energy needs in a sustainable way - and for that, we need solar power. And for effective and efficient solar power, we need to employ nanoscience.”
Prof Schropp was speaking at the opening of the five-day South African Nanoscience And Nanotechnology Summer School 2019, bringing together 120 local and international industry experts, academics and postgraduate students to explore nanoscience matters, “From Research to Applications, Innovation and Commercialisation”.
In his talk on Nanostructured Thin Films For Multiband-Silicon Tandem And Triple-Stacked Solar Cells, Prof Schropp noted that stabilising CO2 emissions at a level that limits global warming to 2o C will require that at least a 14 TW renewable energy capacity be installed by the year 2050.
“If we were going to replace that amount of fossil energy by nuclear energy, we would need to build a power plant every two days, and that would come with some serious safety concerns,” he said. “Other renewable power sources are promising, but don’t scale as easily. It is clear that among the various renewable energy options, only solar energy offers ample resources to cover this demand.”
Given the large scale needed, solar technologies that need to be developed should use earth-abundant and preferably non-toxic materials. Among the various options available, silicon solar cells are dominating the market.
Even though Si is the second most abundant material in the Earth’s upper crust, the high purification that is needed and the indirect optical absorption make it an expensive source material. Therefore, further price reduction has to come from the use of thin films, the implementation of nanostructures, and the use of tandem solar cells utilising the full spectrum more efficiently.
“What we can do is try to make the best possible solar devices that will convince people to adopt solar power for their energy needs - devices that are cheap and efficient, and whose production is scalable,” Prof Schropp noted. “When it comes to solar panels, thinner is beautiful: the light doesn’t have to travel as far, or through as much material, and that means less wasted energy.”
As a source of energy, solar power is in ample supply. To meet the world’s projected energy needs in 2050 using solar cells, we’d only need a few pieces of land: just 1.7% of the land area, globally speaking, would be sufficient.
“Renewable energy supply from solar cells can help build a sustainable society, he said, “and further research can build technologies that are highly efficient and inexpensive, so that solar electricity will be abundantly available to everyone.”
Nanoscience For A Better World
The 5th Summer School is being run by the Nanoscience Hub at the University of the Western Cape (UWC). The hub houses the National Nanoscience Postgraduate Teaching and Training Platform (NNPTTP), which is fully funded by the Department of Science and Innovation (DSI).
The Deputy Minister of Higher Education, Science and Technology, Buti Manamela, opened the School in Stellenbosch on Monday, 25 November 2019.
“The prefix ‘nano’ means one thousand millionth. And indeed, we made small beginnings in order to realise great achievements in this intriguing field of science,” Manamela noted. “Today, there is no doubt that significant research activity is taking place at the majority of universities across the country. While this research is largely fundamental in nature, the scope of areas of application identified in the National Nanotechnology Strategy is being well covered. These areas of application range across water, energy, health and pharmaceuticals, chemicals and bioprocessing, mining and minerals, and advanced materials and manufacturing.”
Given the potentially massive returns of nanoscience and nanotechnology for the development of this country and its people, UWC is proud to be involved.
“The field of nanotechnology is a relatively new one in South Africa,” said UWC’s Deputy Vice-Chancellor: Academic, Prof Vivienne Lawack, highlighting the importance of the nanoscience programmes at UWC, and praising the NNPTTP for producing 151 Masters students in the decade of its existence.
“You have the science,” she told the assembled delegates. “And now the question is: What do you do with it? How do we apply this research in innovative ways, and bring new technology to common use? I encourage all of you, as you deliberate, to think of the impact your work could have, and the vast benefits that we could reap as a society from these interventions.”
Want to know more about SA NanoSchool 2019? Just consult the programme, or visit the South African Nanoscience And Nanotechnology Summer School 2019 website. And why not learn m