Page 94 - Alternative Energy Systems in Building Design

70 SOLAR POWER SYSTEM PHYSICS AND TECHNOLOGIES

The output power of a unit solar cell or its efficiency depends on a number of factors,
such as crystalline silicon, polycrystalline silicon, and amorphous silicon materials,
which have specific physical and chemical properties, details of which were discussed
earlier. Commercially available solar panel assemblies mostly employ proprietary cell
manufacturing technologies and lamination techniques, which include cell soldering.
Soldered groups of solar cells are in general sandwiched between two tempered-glass
panels, which are offered in framed or frameless assemblies.

SOLAR POWER SYSTEM CONFIGURATIONS
AND CLASSIFICATIONS
Types of solar power systems include

1 Directly connected dc solar power systems
2 Stand-alone dc solar power systems with battery backup
3 Stand-alone hybrid solar power systems with generator and battery backup
4 Grid-connected solar power systems

Directly connected dc solar power As shown in Fig. 3.33, this solar system
configuration consists of a required number of solar PV cells, commonly referred to
as PV modules, connected in series or in parallel to attain the required voltage output.
The figure shows three PV modules that have been connected in parallel.
The positive output of each module is protected by an appropriate overcurrent device,
such as a fuse. Paralleled output of the solar array, in turn, is connected to a dc motor via
a two-pole single-throw switch. In some instances, each individual PV module is also

+

Figure 3.33 Diagram of a
PHOTOVOLTAIC MODULES (PV) GND three-panel solar array.