High spatial resolution system for measuring solar and circumsolar radiation

Concentrating photovoltaic systems (CPVs) are sensitive to a correct alignment with current sun position because of the optical principle at the basis of their operation; indeed, the higher the concentration factor, the more sensitive they are. Therefore, solar trackers and high-quality focusing optics are used to maximize the cells’ exposure to sun disk’s radiation. This increases costs, so that viability of CPV systems strongly depends on the location and on high quality information or model of the irradiance conditions. For this purpose, pyrheliometers (or, sometimes, collimated isotype cells) are used to acquire on-site data for direct normal irradiance, but they are not perfectly suitable for CPVs because they have a wider field of view (5°) and so they overestimate the actual irradiance seen by the concentrating system. As an alternative, a collimated sun-scanning setup with an aperture angle of 0.13° has been developed for measuring the solar and the circumsolar radiation distributions with high spatial resolution. In fact it has an angular positioning accuracy of ±0.002° and an angular pointing precision of ±0.007°. It is also intended to provide a simple but effective tool for building up a consistent database of local sunshapes.

SALIS Elena;  VIGANO' Davide;  ZAAIMAN Willem; 

2013-11-27

WIP

JRC82283

3-936338-33-7,   

http://www.eupvsec-proceedings.com/proceedings?fulltext=HIGH,    SPATIAL,    RESOLUTION,    SYSTEM,    FOR,    MEASURING&paper=24933,    https://publications.jrc.ec.europa.eu/repository/handle/JRC82283,