Cost-efficient materials to make solar power more affordable
Solar energy could be used to generate as much electricity in Finland as in Central Europe. Especially the western coast of Finland has many sunny days and there are no mountains or major air pollution that would stop the sunlight from reaching the ground.
If the cost-efficiency of solar power was improved, the use of solar power would become more popular.
According to researcher and docent Hele Savin from the School of Electrical Engineering Department of Micro- and Nanosciences, the high cost of solar energy is partly caused by the materials currently used in solar cells. The research group led by Savin is trying to improve the cost-efficiency of cells by using new, photoactive materials.
Purifying silicon is expensive
At present, the most common material used in solar cells is silicon, the second most abundant element found in the Earth’s crust. Due to its commonness, silicon in itself is not expensive and can be extracted from the bedrock. However, in order for it to be usable in solar cells, it must first be purified.
Savin explains that the currently used purification process is expensive. The silicon must be melted at a high temperature in order to make it crystalline and devoid of harmful impurities and thus suitable for solar cells. Savin’s group is examining the opportunity of by-passing the expensive purification process.
̶ Our idea is that the silicon purification process would be reduced to a minimum and impurities managed in a controlled way by changing their chemical state or physical location so that they would not interfere with the operations of the solar cell, Savin says. With the help of this method, manufacturing solar cells from silicon would become much more affordable than it is today.
An answer to the world’s energy demand?
Covering the world’s energy demand by using nothing but solar power is already technically possible. Savin points to a world atlas with six black dots on it. If the areas marked with dots were covered with solar cells, the sun would make the world go round. No other form of energy production would be necessary.
̶ This fact is indicative of the huge potential solar power has. It also motivates us to carry on with our research.
Researching cost-efficient solar power materials is a consortium project and the participants include Aalto University, VTT Technical Research Centre of Finland, Åbo Akademi University, the University of Jyväskylä and Tampere University of Technology. The project is part of the Photonics and Modern Imaging Techniques programme led by the Academy of Finland.
Text: Tea Kalska
Photo: Hele Savin