A Method for Determination of the Transmission Efficiency of a Silica Optical Fiber Cable Using a Solar Power Tower

After being adequately captured and concentrated, solar radiation can be conducted by optical fiber bundles/cables and directly used for illumination (lighting) or heating of confined spaces, or indirectly used by converting it in other forms of energy (e.g., for producing electricity). This article reports preliminary tests conducted on a 7-m-long optical fiber bundle/cable with an effective aperture circular area of 14 mm in diameter, specially designed and manufactured by a leading company to transmit up to 1000 W_th of unfiltered concentrated sunlight. The cable was tested in the typical receiver position at the top of a solar concentration central tower. The main purpose was the experimental determination of the transmission efficiency of the cable in function of the incidence angle using selected groups of heliostats belonging to the heliostat field. The testing methodology proved to be capable of evaluating the performance of the cable. The cable withstood the tests without revealing any type of damage. The results obtained showed that the transmissivity of the cable is higher than 50% when the incidence angle of the solar radiation is lower than 14.7°, increasing sharply to circa 95% when the incidence angle is lower than 4.5°.