Shading in High-Concentrator Photovoltaic Power Plants

The electrical behavior of high concentrator photovoltaic power plants is affected by self-shading between solar trackers. Partial shading of the concentrator modules on a tracker causes complex effects in the output I–V characteristics. Shadows affect the behavior of the basic component of a concentrator photovoltaic generator, the solar receiver integrated with primary optics, and the electrical connection of receivers with different behavior distortions the system output. In this chapter, measurements of concentrator receivers integrated with partially shaded primary optics are analyzed to understand their electrical behavior and a methodology for characterizing the I–V curve of shaded high concentrator photovoltaic generators under given environmental conditions is described and compared with experimental data. This methodology can be used for carrying out different studies on shading in high concentrator photovoltaic power plants. For instance, time domain simulations that calculate the I–V characteristic curve of a concentrator photovoltaic generator at small time steps can be implemented. These simulations can be used for calculating shading energy losses in grid-connected high concentrator photovoltaic systems or for analyzing important aspects in the design of these plants, such as optimum trackers allocation or inverters configuration. The problem of optimizing trackers allocation is also approached in this chapter with a simplified method based on balancing irradiation losses with energy losses in wires and costs of the land.