## 2 Materials and Methods
The second is that these installation options have a \"mirror\" value of the cosines of the Sun's rays falling on the surface of the panels of vertical stationary PV-modules during the day. The research results can be used for the calculation of the systems of vertical stationary PV-modules with double-sided panels with an \"East-West\" orientation. The peculiarity of the conducted research (Figure 7) lies in the establishment of the following facts. The first is that the weighted average daily installation efficiency of the vertical stationary solar PV-modules with double-sided panels with an \"East-West\" orientation is not the same as that of a \"South\"-oriented PV-module. The second peculiarity is the fact that the installation options have a \"mirror\" value in the cosines of the Sun's rays falling on the surface of the panels of the PV-module during the day. The research results can be used for calculations of the systems of vertical stationary solar PV-modules with double-sided panels facing \"East-West\". Thus, the energy productions of double-sided stationary vertical PV-modules with an \"East-West\" orientation and those of PV-modules installed at a latitude angle with a \"South\" orientation will have the same values. The peak of electricity production for double-sided stationary vertical PV-modules with an \"East-West\" orientation will only be in the morning and in the evening. The peak of electricity production for PV-modules installed at a latitude angle with a \"South\" orientation will be at noon. The study suggests that double-sided stationary vertical PV-modules with an \"East-West\" orientation should be installed along roads or sidewalks facing south. At the same time, such modules are easily integrated into the design of the surrounding space. It is impractical to use PV-modules installed at a latitude angle with an orientation of \"South\" in such a situation, since the area that such modules will occupy will be approximately 10 times larger, and such systems will not be integrated into the design of the surrounding space. It is also obvious that the cost of a system with double-sided stationary vertical PV-modules with an \"East-West\" orientation will be double that of PV-modules installed at a latitude angle with an orientation of \"South\". Based on this, stationary vertical PV-modules with an \"East-West\" orientation should only be used in power supply systems of facilitieswith significant morning and evening load peaks. PV-modules installed at a latitude angle with a \"South\" orientation will, in this case, require a significant number of batteries. In addition, it has been established that double-sided stationary vertical PV-modules with an \"East-West\" orientation can be installed in combination with PV-modules installed at a latitude angle with an orientation of \"South\" in systems that have significant peaks in energy consumption in the morning and evening. At the same time, double-sided stationary vertical PV-modules with an orientation of \"East-West\" can be installed along fences and sidewalks, and will complement PV-modules installed at a latitude angle with an orientation of \"South\", which are installed on the roofs of buildings. The cost of electricity generated by double-sided stationary vertical PV-modules with an \"East-West\" orientation installed in combination with PV-modules installed at a latitude angle with a \"South\" orientation, at a solar radiation intensity of 600 to 1000 W/m\({}^{2}\) and a solar energy conversion efficiency of 22.5%, will be from EUR 65 to 108/kWh. When using PV-modules installed at a latitude angle with a \"South\" orientation and batteries to supply power consumers during morning and evening peaks of energy consumption, the cost of energy storage will be about EUR 300/kWh. Thus, the use of double-sided stationary vertical PV-modules with an \"East-West\" orientation is approximately 3 times more efficient than the use of batteries.