| dc.description.abstract | Solar concentrating photovoltaic (CPV) systems have the potential to achieve higher efficiency and reduce total system cost. The main idea of (CPV) technology is to use cheaper optics such as lenses and mirrors to concentrate the sunlight onto a tiny area of photovoltaic (PV) cells. In this case, the required PV cell area is reduced with a given amount collection of incident power. There are several advantages of CPV systems. First, the cost of the PV system can be reduced by replacing a large area of expensive PV cells with less expensive optical elements, which allows to use the most efficient multijunction (MJ) tandem designed cells which is also the most expensive cells. Also, the efficiency of PV cells can be significant increased under concentrating system. CPV system can be more cost competitive with other PV and electricity generation technologies because of its high efficiency.
However, traditional CPV systems have the problems of the high temperature and non-uniform irradiance on the solar cell at high concentration ratio, which can reduce the performance of the PV cell. Because of these disadvantages of the conventional CPV system, planar waveguides which are used as the secondary optics have been developed for CPV system since 2010. The advantage of the use of the waveguides as the secondary optics is that it can provide uniform illumination on PV cell and may have additional concentration.
Our designed lens-to-channel waveguiding concentrator contains channel waveguides array, a lens array and MJ cells. Compared with the single Fresnel lens, using a lens array as the primary concentrator can not only collect a large amount of solar radiation, but also reduce the thickness and weight of the whole system. In this system, any decoupling loss in the waveguide can be avoided.
The simulation and experiment results of three designed system are presented in this thesis. The concentration ratio can be increased to 920x if using tapered waveguide. A system efficiency of 86% can be achieved by using low loss material as the waveguide. | en |
