An optical characterization platform for transparent insulation materials in solar energy
- Fraunhofer-Inst. for Solar Energy Systems, Freiburg (Germany)
The precise optical characterization of transparent insulation materials used in windows, flat-plate collectors or for transparent insulation of buildings, is an important step to design solar collector and daylighting systems with these materials and to estimate energy benefits, peak loads, efficiencies, and different potential risks such as overheating, thermal damage or glare. Physically the aim is clear: Angle-dependent transmittance and reflectance properties for the solar and visible wavelength ranges yield the necessary information for the engineer to enable him to design a good system. However, it is far from trivial to obtain these data with sufficient precision for the rather different materials. The authors have set-up a set of radiation sources and integrating detector spheres which are able to measure directional-hemispherical and hemispherical-hemispherical reflectance and transmittance (hence also absorptance) for the visible and the solar wavelength range. This was possible by applying a PTFE-based coating to the spheres, having a unique spectrally flat response over the whole range, and using non-selective broadband detectors. Careful design tried to optimize integrating sphere geometry. Moreover, spectral measurements between 285--1,100nm are possible with an optical multichannel analyzer utilizing glass fiber optics. The whole experimental set-up will be presented and discussed together with representative results.
- OSTI ID:
- 194865
- Report Number(s):
- CONF-9404167-; ISBN 0-8194-1564-2; TRN: IM9611%%367
- Resource Relation:
- Conference: SPIE 13: international symposium on optical materials technology for energy efficiency and solar energy conversion, Freiburg (Germany), 18-22 Apr 1994; Other Information: PBD: 1994; Related Information: Is Part Of Optical materials technology for energy efficiency and solar energy conversion XIII; Wittwer, V. [ed.] [Fraunhofer Inst. for Solar Energy Systems, Freiburg (Germany)]; Granqvist, C.G. [ed.] [Uppsala Univ. (Sweden). Dept. of Technology]; Lampert, C. [ed.] [Lawrence Berkeley Lab., Berkeley, CA (United States). Energy and Environment Div.]; PB: 863 p.; Proceedings/SPIE, Volume 2255
- Country of Publication:
- United States
- Language:
- English
Similar Records
Durability testing of antireflection coatings for solar applications
Integrating sphere spectrometer for high-temperature materials characterization