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

The operating characteristics of a commercial monocrystalline and amorphous Sisolar 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.

Additional Lighting Effects for Photovoltaic Improvements in the Performance of Solar Cells

“…We compare only data observed under the same light intensities (with and without the WFL system) and the same light spectra. [ 35,37,38 ] The decrease of the FF is more pronounced at lower light intensities than at higher ones for both measured monocrystalline and amorphous Si‐solar cells studied. The most common explanation concerning the FF is the fact that the FF decreases with increasing illumination intensity, increasing absorber thickness, and long‐wavelength illumination, for instance, in amorphous silicon (a‐Si:H) solar cells.…”

“…We again stress here that the expression for the efficiency calculation at least does not take into account the different light distributions that reach the solar cell as well as possible additional light effects that could also influence the expression. So, for that reason, in our published results so far, [ 34–38 ] the efficiency after light manipulation (after using the WFL system) has not been calculated; in contrast, the value would be unreal and very high. As can be seen in Figure 2b, dependence follows the same trend as presented in Figure 2a.…”

“…The next Figure 5b also follows the same improvements in I sc and V oc with the used WFL system specified for another monocrystalline high‐efficiency Si‐solar cell, KXOB22‐01X8F‐ND. [ 35 ] The short‐circuit current ( I sc ) to input light energy ( P input ) ratios for indoor lighting are 5.2 and 24.8 without and with the WFL system, respectively. Outdoor lighting exhibits a significant increase in short‐circuit current, up to more than five times that measured under STCs.…”

“…Measurements and details are given in separate publications; hence, we mentioned only some of the details of interest. Testing of the WFL system was conducted in parallel on several solar cells: four commercial ones (monocrystalline Si, KXOB22‐01X8F and KXOB22‐12X1F, and amorphous Si, AM‐5907 CAR and AM 1816 CA solar cells [ 35–39 ] ), as well as some of the laboratory‐made solar cells, differently designed Sb 2 S 3 ‐based solar cells based on synthesized undoped and doped Sb 2 S 3 nanomaterials, [ 16,36,39–44 ] and dye‐sensitized solar cells (Dyesol/Greatcell Solar DSL 30 NRD‐T). [ 45 ]…”