Environmental Engineering Reference
In-Depth Information
refined to a purity level of at least 99.9999 per cent in order to function effectively. So
onerous are the research, development, and production costs of solar technology that, like
nuclearenergy,itwouldprobablyneverhaveemergedwithoutmajorstateinvestment.This
investment was forthcoming thanks first to the space race, then to the oil crises and, more
recently, to the drive for cleaner and more sustainable energy.
Figure 4.29.
One of the authors installing a 4.7-kilowatt PV plant on the roof of his
house.
Source:
Gian Andrea Pagnoni.
PV cells require protection from the elements and are therefore usually encased in glass.
When more power is required than a single cell can deliver, cells are connected to form
PV modules. Modules are the fundamental building block of PV systems. A single module
is enough to power certain applications, such as an emergency roadside telephone, but for
a house or a power plant the modules must be arranged in multiples as panels and arrays.
Panels are pre-wired and ready to install. The modular design of a PV panel is one of
its greatest advantages. As demand grows or shrinks, a plant can be easily expanded or
downsized. It is also possible to mix panels from different manufacturers, provided they
have the same voltage output. A PV array consists of a number of individual PV panels that
have been wired together in a series. An array can be as small as a single pair of panels or
large enough to cover several hectares.
