Analysis of one-axis tracking strategies for PV systems in Europe

We present a method for estimating the energy output from one-axis tracking non-concentrating PV systems and compare the yields from different configurations. The method is based on the use of solar radiation and temperature databases and models for the performance of PV modules under given geographic conditions. In the resulting maps of energy yield for Europe it is found that there are two different one-axis configurations that perform almost as well as a full two-axis sun-tracking system: one with a vertical axis and inclined modules, and the other with an inclined axis directed north south and modules in the plane of the axis. When the inclination angles of the modules are optimized, these two configurations have an energy yield compared to an optimal fixed mounting that is approximately 30% higher in southern Europe, about 20 25% higher in central Europe, and up to 50% higher in northern Scandinavia. Compared to the two-axis tracking, the yields are only 1-4% lower, making such one-axis tracking systems very attractive in terms of performance relative to technical complexity and price. (C) Copyright 2010 John Wiley & Sons, Ltd.