Abstract
The article presents the results of a 13-year tests and analysis of performance and energy and electrical charge yield for typical photovoltaic modules made of different absorbers. Modules were installed on the south wall of Opole University building (at kard. B. Kominka Street). Registered in this period (2001-2013) values energy and charge of tested modules are presented in reference to 1 Wp their nominal power and to 1 m2 of PV modules. Their annual and monthly distributions, with particular emphasis on the seasonal changes of its parameters and phenomena of aging and degradation of the PV modules structure were shown. In the final part of the article was presented an economic analysis of the profitability of investment in 20 kWp grid connected PV system with and without implemented the program to support investment in renewable energy, which respect to the newly implemented in Poland Act on RES.