Solar energy has potential to provide electricity for all
15 July 2010
The solar cells that are installed around the world today produce as much energy as an entire nuclear power station. The supply of solar energy is enormous, and Uppsala University is conducting research to develop even more efficient solar cells.
“Solar cells are the best way to take advantage of the energy provided by the sun. Electricity comes directly out of the solar cell,” explains Marika Edoff, who directs a research team at Ångström Laboratory that is working with so-called thin-film solar cells.
As more and more solar cells are produced, the price of solar energy is dropping. At the same time, the price of electricity has been generally rising. The future of solar power looks very promising, according to Marika Edoff. Moreover, it leaves the smallest environmental footprint among technologies for electricity production, and it is the only type of energy that has the potential to cover all of the world’s energy needs.
“Warm countries with large populations have the best conditions to benefit from solar energy. They need huge amounts of energy for cooling during the day, the time that solar cells produce electricity. In Sweden we need the most energy during cold, dark winter nights – a less suitable match-up with solar energy. For efficient use all day and year round, good storage systems are needed.”
Solar cells convert sunlight into electricity. The photons in the light give their energy to the electrons in the solar cell. The energy-rich electrons can only move in one direction and gather on the upper side of the solar cell. Peppy electrons leave the solar cell and are put to work as energy outside the cell. Then they are led back.
Marika Edoff and her colleagues are researching CIGS solar cells. The total thickness of the solar cell layers is less than three micrometers, that is, three thousandths of a millimeter, and the technology has the potential to achieve low costs compared with the solar cell technologies that dominate today.