PV systems convert solar radiation into electricity. They are not to be confused with solar panels which use the sun’s energy to heat water (or air) for water and space heating. This chapter looks at PVs and examines a number of issues of interest to designers including:

2.2 PVs

The most common PV devices at present are based on silicon. When the devices are exposed to the sun, direct current (DC) flows as shown in Figure 2.1 (see Appendix A for greater detail). PVs respond to both direct and diffuse radiation (Figure 2.2) and their output increases with increasing sunshine or, more technically, irradiance (Figure A.3).