Photovoltaic (PV) windows represent a novelty in the field of building integrated photovoltaics (BIPV). Within the Laboratory for Photovoltaics and Optoelectronics (LPVO) we carried out a project of the implementation of PV windows as a part of the renovation of the Faculty of Electrical Engineering.
The operation of PV windows can be monitored live on this website.
Each PV window consists of 28 double-sided solar cells that convert both external and internal light into electricity. Two photovoltaic windows are connected in series, for a total of 56 solar cells. In the LPVO we measured the maximum power of the external side (sunlight-illuminated side) of both PV windows, totaling 224.7 W under standard test conditions (power density of solar radiation 1000 W/m2, solar cell temperature 25 °C and wind speed 1 m/s). Due to the low intensity of the illumination, the inside of the modules negligible contributes to the total power.
Photovoltaic windows are via wires connected to a micro-inverter with a rated power of 260 W, which is sufficient for the serial connection of the two windows. The inverter is located in the basement room, which beside the wires that are invisibly placed in the window frame, represents a seamless integration of the photovoltaic system into the building of the Faculty of Electrical Engineering. Besides the inverter, there is an electric cabinet containing fuses and a switch that allows the system to be disconnected from the network.
In addition to the elements that ensure the safe connection of PV windows to the electrical network of the Faculty of Electrical Engineering, there is also a communicator in the cabinet that enables wireless connection to the micro inverter. The communicator is connected to the World Wide Web, which allows access to the inverter power data through a web site. The website is easily accessible to visitors of the faculty via a smartphone using a QR code that is placed at PV windows. The website also provides basic weather information, namely the air temperature and the sun's irradiance to the plane of PV windows.
The PV window project was created through the cooperation of the LPVO and the Slovenian industry. Both the micro inverter and PV windows are the result of Slovene knowledge and are produced in slovenia.