- portal for building integrated photovoltaics

Energy yield

In the course of the simulation, annual energy yield of the different façades was also computed. The façade with photovoltaic sunshading has the lowest yield because of its small photovoltaic area (3.5 m²). Slightly higher is the yield of the double façade with photovoltaics, as this was based on a façade using semitransparent thin-film modules. The thin-film modules have an efficiency of just 7% compared with the crystalline modules (14%) of the other types of façade. The PV façade with an installation angle of 75° yields most energy, 896 kWh/kWp. Yield decreases as the angle of installation increases.
Figure 1: Annual energy yield of the simulated façades (kWh/kWp), façade area: 14m²
The graph of area-specific energy yield shows that the façade with photovoltaic brises soleils angled 30° has the biggest yield. This confirms that yield is greatest in Central Europe at an installation angle of approx. 30°.

However, the area-specific yield of the PV façade at 90° is greater than that of the PV double façade, that also has a 90° inclination. The reason for this is the low efficiency of the thin-film cells used in this type of façade.
Figure 2: Area-specific energy yield (kWh/m²) of the different types of façade
The running costs due to the cooling and heat demand of the building and the revenue from power production are factored into the economic efficiency calculation along with other parameters.

Last page update: 25.01.2011