A dish-type high-concentration photovoltaic system with spectral beam-splitting for crop growth

Abstract

Photovoltaic (PV) systems are playing a more and more important role as a renewable energy supplier. However, their large-scale applications is still limited by low conversion efficiency and high land-use requirement, especially for those areas where land and solar energy resources are more important for agriculture. In this paper, we suggest a dish-type high-concentration photovoltaic system, with which the competition between sunlight for crops' growth and PV application is solved by beam-splitting techniques. A purposely-designed beam filter acts as a solar spectrum splitter, and the most effective bands of solar spectrum for plant growth are transmitted down to plants while the other parts are all directed to the solar cell receiver. The spectral and spatial distribution of radiant intensity is investigated by ray tracing method, and the quantitative evaluation of the beam splitting effect on crop growth and PV power generation is provided in detail. The results show that, on one hand, the proposed system is superior to other natural and artificial light sources at driving the photosynthetic process (thus promoting crop growth); on the other hand, it generates PV power with high efficiency. Furthermore, the design can be optimized for certain kinds of plants and PV generation, both or independently. This spectral splitting scheme opens a promising future for PV applications in cooperation with precision farming.