Bio-Inspired Design and Fabrication of a Spectrally Resolved Albedometer

Abstract

With the increased market share of bifacial modules, it is becoming increasingly important to have sensors that provide information about the irradiance falling into both sides of the modules. Such instruments give more information about the performance of PV modules. They can optimize the material, tilt, and orientation of PV modules according to the surface on which they are installed. However, most sensors in the market do not provide spectrally resolved data, and the ones they do can be expensive.

Because of the preceding, this thesis aimed to design and fabricate a cost-effective spectrally resolved albedometer that will measure the global and reflected irradiance in three different parts of the solar spectrum using photodiodes as sensing elements. This thesis demonstrates how the device's optical, electrical, and mechanical characteristics can be optimized to obtain a more accurate estimation of the spectral albedo.

Additionally, a bio-inspired casing design with self-shading properties was created to reduce the temperature inside the device. Two prototypes were fabricated with two different colour-diffuser configurations (Grey-N-BTK diffuser and White-Hybrid diffuser). Data measured by the final prototypes was calibrated and validated with measurements from an EKO MS700 spectroradiometer. The final sensors have an average error of 20.4% and 7.3% and operate at 17ºC and 8.6ºC above ambient temperature. The albedometers have a volume of 810 cm2 and cost around €978.