Nowadays, photovoltaic systems installed in urban areas may be essential for distributed
generation and lead to increase energy security and improve economy of building
exploitation. Unfortunately, in many cases their operation in urban area is not so efficient. It
is connected with shadowing by neighbouring buildings, trees or by the HVAC systems
installed on roofs (including such elements as fans, compressors, etc). Moreover, HVAC
systems often occupy" the best" place on roofs. Level of shadowing varies during a day, and …