February 6, 2009 Researchers in Australia have started a three-year project to develop a spray-on coating for solar panels and more efficient cells that are less costly than today's PV. Australian National University (ANU) is working with new Australian solar company Spark Solar and Finnish materials company Braggone Oy on the method, which could be commercially available by 2011.
Solar cells are typically made of silicon coated with a thin layer of silicon nitrate - which is used as an anti-reflective agent to increase cell efficiency. However, these types of cells are costly to produce because the anti-reflective layer must be deposited in a vacuum.
The new method uses a spray-on hydrogen film and spray-on anti-reflective film. Instead of needing a vacuum, the cells travel along a conveyor belt where the films are sprayed on. The simplified process could reduce about $5 million in capital equipment costs per medium-sized factory with these savings resulting in cheaper solar cells. Testing of the process is now taking place at the ANU, and the technology should be available toward the end of 2011.
“It will provide an opportunity for significant manufacturing cost reductions by replacing the conventional, expensive manufacturing techniques that are currently employed industry-wide with the spray-on films,” said Dr Keith McIntosh from ANU, the chief investigator in the first project.
Improve efficiency
The second project will investigate methods to change the surface of a solar cell to improve its efficiency. Presently, solar cells on the market range from 5 to 24 % efficient. Most of the cell energy is lost at its surface where the material is roughened. This is to increase the surface area that can absorb solar energy. However, roughening the material also disrupts the cell's crystalline structure in the process.
Once an optimal surface is found, the cost of the cells would remain the same, but their efficiency and power would be improved. This project will be run in conjunction with German solar company GP Solar and led by chief investigator Dr Klaus Weber from ANU. “We aim to develop a range of industry-ready cell fabrication sequences that will offer significantly improved conversion efficiencies” Dr Weber said.
The projects are a further extension of solar research at ANU, which is recognized internationally as a leader in the research and development of photovoltaics. The Australian Research Council under the Linkage Projects scheme supports both projects.
19 Million cells a year
New Australian Company Spark Solar will build a $70 million high-tech solar cell factory in the Australian Capital Territory (ACT) to commence solar cell production in 2010. The factory will be designed to produce 19 million solar cells a year enough to power 20,000 homes, with exports worth more than $400 million to Europe's booming solar markets.
Spark’s Interim CEO Dr Michelle McCann said that in the current booming solar market it is essential for photovoltaic companies to be dynamic and innovative in order to be successful. “Spark plans to stay at the forefront of advances in manufacturing technology via innovations likely to arise from collaborative research projects such as these,” Dr McCann said.
Global demand for solar cells is so strong that Spark is now finalizing a contract to sell half its output to one of Europe's biggest solar panel manufacturers. Dr McCann said, ''The market for solar cells is enormous and there are not enough cells being made globally to meet demand. Even before the factory is built, we expect to pre-sell almost all of our output for the first five years.''
The global market for solar cells is growing at a faster rate than markets for laptops, mobile phones and digital cameras.
Last year, the global photovoltaics market grew by 70 per cent, to A$ 21 Billion (US$ 13.8 B). Dr McCann said ''Australia is a world leader in solar technology. But sadly the small manufacturing base that exists here means that a lot of really excellent talent and research has gone overseas in the past. We want to change that.''
The company will initially export 90 per cent of its product and will be Australia's biggest manufacturer of solar cells. A state-of-the-art factory, designed and pre-fabricated in Germany, will be built next year, with the solar cell production beginning in early 2010.
Paul Evans
