Sunny times ahead for cheaper solar power

Greater use of clean electricity from the sun should be a step closer, thanks to new research carried out in the UK.

The research has shown how the cost of generating solar electricity can be reduced, laying the foundation for a major expansion in the use of this sustainable energy technology.

The project has been undertaken by a team of physicists, chemists, material scientists and engineers at Sheffield Hallam University, with funding from the Swindon-based Engineering and Physical Sciences Research Council.

Electricity generation through the interaction of the sun’s heat and light with semiconductors is called photovoltaics (PV). Although PV’s environmental benefits are well-known, take-up of the technology has been limited by the relatively high cost of the solar cells that incorporate these semiconductors.

The team at Sheffield Hallam University has been exploring a range of options for cutting costs. These include the use of a low-cost semiconductor production method called electrodeposition, less reliance on expensive semiconductor materials, and the identification of alternative solar cell devices and manufacturing techniques offering higher conversion efficiencies.

Higher conversion efficiencies mean that more power can be produced per cell and that the cost of each unit of electricity generated is reduced. In the past, limited understanding of the scientific principles underlying PV meant that average solar cell efficiencies only improved from 15.9% to 16.5% between 1992 and 2001 for cadmium telluride based solar cells. By formulating a new “model” to describe the photovoltaic activity of these solar cells, the Sheffield Hallam Team has significantly improved this understanding and produced devices with 18% efficiency. This has opened up the prospect of new solar cells being developed commercially with higher conversion efficiencies than those currently available.

The research has been led by Dr I M Dharmadasa, who says: “We’ve already applied for two patents and are preparing the final draft of the third patent in connection with our work, but there’s a lot more science to be explored that could increase conversion efficiencies to over 20% in the near future”.