A typical PV array consists of one or more PV modules electrically connected with each other. When PV modules exposed to sunlight, convert approximately 14% of incident solar energy into electricity.

Photovoltaic systems offer high and guaranteed yield, need little maintenance, are reliable with long life, and have expansion capability. Divided into stand alone or grid-connected can be installed on roofs of existing buildings, in any open-enclosure space, in fields, squares, streets, etc. For every installed kW it takes about 7-10 m2.

The main characteristics of PV systems, which differentiate it from other forms of renewable energy are :

 The direct production of electricity, even in very small scale, eg at some Wp.

 It is easy to use as small systems can be installed by the user themselves

 Can be installed in cities and embedded in buildings where do not offend the aesthetic environment.

 They can be combined with other energy sources (hybrid systems).

 It is scalable systems, i.e. can be extended at a later stage to meet the growing needs of the user, without converting the original system.

 They operate quietly and emit zero pollutants without environmental impact

 Maintenance requirements are virtually zero.

  They have long life span and are reliable during operation. Guarantees that given for PV generators are more than 25 years of good operation.

PV systems contribute significantly to «Distributed Power Generation», which constitutes a new development model of modern energy production systems, transportation and distribution of electricity. The diversification of energy production, provided by PV systems, combined with a large proportion of dependence on oil and prevent further pollution of the environment can create conditions for economic development to a new energy scene that is currently under shape in developed countries.