Applications in the fields of daylight and architecturally integrated photovoltaics can be simulated exactly in this laboratory. The internationally validated Radiance light simulation software forms the basis for this work, supplemented by innovative BSDF material models, photon mapping and the climate-based annual simulation.
In the daylight field, reliable conclusions can then be drawn for saving energy and increasing comfort of different products in a range of room arrangements and locations. In the daylight field, the reflections of PV façades and roofs can also be quantified and thus reduced during the planning phase.
The laboratories are supplemented with hand-held devices for determining brightness, global radiation, the light and color spectrum, plus the shading and current-voltage curve of photovoltaic modules.
The RG EASE, part of the Competence Center Building Envelopes can measure the spatial diffusion of light under constant laboratory conditions by using the goniophotometer, of which only three are used at university-level institutions worldwide. The sample is lit by a bundled reference source so as to reflect and transmit light in various directions.
The light is detected by a sensor that tracks over 100,000 measuring points on a spherical surface surrounding the sample. The relative brightness in every solid angle is used for calculating light scattering. This is known as the Bidirectional Scatter Distribution Function (BSDF) because it depends not only on the solid angle of the outgoing light but also on the angle of incidence of the reference beam. In this way, the light deflection and antiflex properties of daylight control systems or solar glazing can be quantified exactly, for example.
The horizontal global and diffuse solar radiation at the Horw campus is recorded using pyranometers. To measure the diffuse radiation, a pyranometer is equipped with a shade that blocks direct sunlight. The direct radiation is determined from the difference between the global and diffuse radiation. All data is provided for simulation programs.