SA company’s solution to energy crisis
The cost of generating electricity by solar technology has finally dropped below that of conventional fossil fuel technology and is promising a more stable electricity supply in the near future.
But the real deal maker should actually be solar power’s flexibility and adaptability to needs and requirements.
This is one of the realities that hit home on a visit to Photovoltaic Technology Intellectual Property (PTIP), a wholly owned South African company, where some of the latest solar panel technologies are being developed and already being produced on a limited commercial scale.
And another is that solar panels no longer have to be mounted on top of your roof – they can be the roof, as the PTIP panels are strong enough and thin enough to be used as large roof tiles, while their black colour would make them aesthetically acceptable.
PTIP is known as the thin-film photo-voltaic pioneer in South Africa and counts among the leaders in the technology world-wide, thanks to the research and development done by its chief executive, Professor Vivian Alberts of the University of Johannesburg, and his staff of highly qualified experts.
Situated in the leafy environment of the Stellenbosch Technopark, PTIP is one of those manufacturing facilities where the loudest noise comes from the human voices inside. And even that is somewhat muffled by the surgical masks the staff have to wear inside the production units.
The construction of these hi-tech thin film panels requires the cleanest, most dust-free environment possible. As a result, staff working inside the production area wear lightweight dust-containment gear.
Although thin film technology no longer depends on silicon as a base, it still needs a glass carrier, and it is a special glass that has to be as clear as you get and as clean, too. The glass panels brought to the production unit have to be washed with ultra-clean ionised water that has been put through an osmosis process to extract all the impurities.
“We are still importing glass from Germany, because the glass we need has to answer to very clear standards, but we are working with a local producer to do it here so we can increase our local content,” Alberts explained.
“This is essentially 85 percent a South African product, based entirely upon South African technology, and there should be no doubt that we should also produce it here. Why develop something here and then send it out for manufacturing in China or elsewhere while we so urgently need to create jobs here?”
And that is why the Industrial Development Corporation and the national Department of Science and Technology had committed all the money needed to fund production, making the state the largest single shareholder.
The thin film chemistry sounds like the stuff of science fiction. The technology with which to produce homogeneous four-part and five-part chalcopyrite alloys is patented worldwide.
A two-step procedure is used to produce the complex semiconductor materials with unique properties that suit the specific function required of the panels the best.
First, a copper-indium-gallium metallic precursor is prepared under high vacuum conditions by atomic layer deposition in what is called a sputter system. Sputter deposition is a physical vapour deposition method that works by ejecting material from a source on to a substrate such as the glass panels the Alberts method requires. The metallic alloys are then exposed to a mixture of gases under controlled pressures and temperatures.
The semiconductor layers thus created on the glass panels are then cut by a high-accuracy laser to form the many cells required in the panels. Alberts points out that his panels are so light sensitive that they begin turning photons into electricity the moment the first light of day appears. “In the morning, when you begin to see for the first time, the panels start working.”
And it is this sensitivity that allows these panels to be so competitive. Despite the incredibly hi-tech manufacturing process, the panel is still more affordable than its older technology silicon competitor – it is more durable and more efficient.
“Solar technology can be packaged according to the need. One can design a package for individual households, for farms, small communities, industrial applications and all the way up to utility scale,” Alberts said.
“We now have battery technology readily available that is competitively priced and guaranteed for at least 15 years. The panels are guaranteed for 25. The numbers are already looking much better than (those) of Eskom. And then you have to consider the fact that Eskom will in future demand increases in tariffs every year, which you won’t have once your solar system is installed.”