The influence of the water flow lens system on the operating characteristics of monocrystalline and amorphous Si‐solar cells for outdoor and indoor use: The photovoltaic improvement

Abstract

AbstractThe operating characteristics of a commercial monocrystalline and amorphous Si‐solar cell for outdoor and indoor applications with and without the use of the water flow lens (WFL) system are explored and reported. The cells are tested in indoor conditions with halogen and tungsten lamps, and additionally, in outdoor sun radiation. Changes in the spectra, investigation of the influence of higher and lower lighting, and indirect cooling of the solar cell are possibilities in the application of the used WFL system. After achieving the highest level of development and improvement for the Si‐solar cell, as well as approaching theoretical maximum efficiency, it is obvious that efficiency gains can be made by better understanding additional light effects. Measurements made on monocrystalline Si‐solar cells revealed that in the “focal point position” where intensity increases (above standard testing conditions [STC]), independently of indoor or outdoor lighting, huge improvements in ISC and VOC were observed. It was found that the ratios of the short‐circuit current (ISC) and the input light energy (Pinput) are 5.2 and 24.8 for artificial light and 4.9 and 17.6 for outdoor light, without and with the use of the WFL system, respectively. The same trend after applying the WFL system was observed for the amorphous Si cell, except those oscillations were more pronounced at lower light intensities (far lower than STC), as expected. The ratios of ISC and Pinput are in the range of 5.1–5.3 and 10.5–26.5 without and with the use of the WFL system.