A strongly developing sector of the small scale photovoltaic (PV) systems are the urban applications. There are a lot of compromise where and how to set up these systems in a crowded city. A lot of limiting constraints such as roof space available, shadow effects, orientation of the roof, etc. Because of the disadvantageous ideal circumstances appear the multi-tilted PV systems, where some strings or some element of the string is oriented in different directions. In this paper we give the basics of the energy yield calculation and also compare these calculations to real measurements.