Single-family house in Lasa
BIPV system as central component of the main building façade (building owner) In 2007, the chartered building surveyor Coletti Renato was commissioned by the owner to design the house. The construction works took about 4 years. After comparing different quotes of PV manufacturers, EnergyGlass Srl was chosen for the modules supply and the BIPV system design. EnergyGlass Srl also managed the bureaucracy around receiving government incentives. The owner installed the system himself with the help of specialists. Later, additional PV modules were applied on the building roof in order to supply the total boiler energy demand (building owner).
Aesthetic integration
The PV system is integrated into a 2-storey residential building located in a small village of Val Venosta, along the Adige River. It consists of semi-transparent glass modules installed in the glazed balconies railings on the first level. The modules represent a barrier that protects the large windows characterizing the main building façade, without blocking the mountain landscape view from inside. Their pattern highlights the building’s horizontal development. Due to the refined design, the BIPV system combines the energy production functionality with an aesthetically pleasing aspect.
Energy integration
The BIPV plant was designed to provide a yearly energy of around 800 kWh. Its electricity output, together with the production of additional PV modules located on the roof (1 kWp), supplies the energy demand of a connected PV-Heater (REFUsol), which is used to heat up tap water with a heating rod in the house’s hot water tank. The two PV plants form a stand-alone system which is able to cover the whole building’s thermal energy need (building owner).
Technology integration
The BIPV plant is made from 6 frameless modules (EGM 84-90 ST), which are assembled using laminated safety glass (10 + 10 mm). The PV cells between the glass layers are spaced out leaving gaps of 2–5 cm, thus making the modules semi-transparent (37–38%). The modules are connected to inner bypass diodes, which do not require the modules to be divided into sub-modules. Two junction boxes are placed at the bottom of each glass panel. The PV mounting system (Q railing Easy Glass Slim) does not require holes because the laminated glass is wedged into a 120 mm metal rail all along the balcony which also guarantees the water drainage.
Decision making
The owner decided to integrate photovoltaic modules into the balcony’s railings when the building construction was almost completed. Primarily, the PV plant is a useful solution to supply the boiler energy demand, previously supplied by a pellet stove. Second, the owner wanted to use a semi-transparent shading device to partially cover the view into the large windows, initially thinking about a satin or serigraphic glass solution. The final BIPV solution was found visiting a PV products exhibition, where he compared different solar glass solutions and found the best one (building owner).
Lesson learnt
The building owner carried out a detailed evaluation before deciding to integrate the photovoltaic technology in the glazed parapet. He wanted something that could partially cover the windows, so he also considered to install satin or serigraphic glass. An economic assessment revealed that the glazed PV could be quite competitive with the glass. Aesthetically, quite the same striped texture could be produced. So, the photovoltaic option has been preferred (building owner). The low amount of energy production and the lack of a suitable storage solution on market, in 2012, led the owner to connect the photovoltaic plant to the PV heater exploiting in a different way the generated electricity. The current innovation level reached on the photovoltaic market allowed him to re-think other possible solutions, as using an inverter with integrated energy storage (building owner). This confirms that the energy integration aspect is becoming more and more important in BIPV.
