Concentrating PV employs optic elements to concentrate sunlight onto cells which are much more efficient and smaller than conventional cells. These optic elements allow the concentration of sunlight, multiplying its intensity by factors that range from 2, in low concentration, to more than 1000, in high concentration. Given that the efficiency of CPV cells tends to increase with concentration, CPV can afford to reduce the use of semi-conductive material used in cells without lowering the overall efficiency of the system.
Currently, most CPV companies employ triple junction cells. Mass produced multi-junction cells have reported efficiencies of 35% to 39%, which exceed the efficiency of conventional silicon cells by a wide margin. The combination of high efficiency cells with optic elements allows CPV to produce the same amount of energy whilst using 1775 times less cell surface than standard PV systems . Given that the semiconductor materials that make up the cells are the most expensive, this should result in a reduction in the cost per kWh.
Despite its potential for staggering cost reductions, CPV is still relatively costly. According to a CPV today report , the costs of CPV are around 0.31 to 0.39 € per kWh. These high prices are partly due to the small scale of most CPV installations. However, dramatic cost reductions are expected in the coming years, bringing CPV within an affordable cost bracket of 0.12 to 0.15 € per kWh in 2015 in places with a level of solar irradiation of 2500 kWh/m2/year.
Increases in cell efficiency and optic elements will be crucial factors in bringing about these cost reductions. It is expected that in 2015 triple junction cells will reach record efficiencies of 50% while optics systems could reach between 80% and 90%.
