Concentrating on Solar - Isis Project No 3963

Concentrating sunlight on small but highly efficient solar cells has the potential to provide cost-effective, large-scale electricity generation. Solar concentrators are a key factor in the growth of this industry and scientists at the University of Oxford have developed solar concentrators with high concentration factors (>1000) that potentially cost less than those commonly available.

A Cost Effective Alternative to Photo-Voltaic Cells

The solar power industry is growing rapidly, with solar powered heat engines and Concentrated Photo-Voltaic (CPV) systems being significant areas of high efficiency generation. CPV systems use high efficiency small area photocells onto which solar energy is focussed to provide electricity directly.

The benefits of CPV compared with traditional Photo-Voltaic devices are:

• The efficiency of CPV is approximately double that of conventional Photo-Voltaic cells;
• The cost of CPV is much lower than Photo-Voltaics, as the cost of per cm² of the optical concentrator is much less than that of the photocell;
• As much less photo-voltaic material is used, CPV systems are less susceptible to material suppy constraints.

A critical element for heat engines and CPV are cheap and efficient solar concentrators, as the CPV cell only represents 20-30% of the complete system cost, reduction of the cost of the concentrator is vital.

Reduced Manufacturing Costs, Increased Efficiency

The Oxford solar concentrator uses a combination of single curvature reflectors which has not been exploited before which, acting together, provide a point focus.  A single curvature concentrator, such as a linear parabolic trough concentrator, has a concentration factor of only ~100; estimates for the Oxford system give a concentration of about 8000.

Single curvature surfaces can be manufactured readily made from a flat sheet, and are easily formed into the correct curvature, this is a much cheaper process than the manufacture of conventional parabolic (or spherical) dishes.

Patent Status

The Oxford invention is the subject of a patent application. Isis would like to talk to companies interested in commercial opportunity. Please contact the Isis Project Manager.

Request Further Information: Project Number 3963 - Concentrating on Solar