Use of Pigments Present in the Crude Aqueous Extract of the Spinach for the Simultaneous Solar Power and Storage at Natural Sun Intensity

Abstract

The photogalvanic (PG) solar cell technique discussed in the present study has potential for both solar energy conversion and solar power storage at a time. The harvesting of the solar energy using costly, polluting, and synthetic dye sensitizers cannot be a sustainable method. Furthermore, the sensitizers including the natural sensitizers must be capable of showing simultaneous solar energy and conversion at natural sunlight intensity. With this aim, therefore, the PG cell using cheap and easily obtainable aqueous crude spinach extract for harvesting natural sunlight for solar power generation and storage is fabricated and studied. Herein, it is shown that this extract can also be an efficient sensitizer in the PG cell technique for harvesting energy from the natural sunlight by following the same cell fabrication principles as applicable for the synthetic dye photosensitizers at artificial and low illumination intensity. A very good open-circuit potential (1.088 V), steady-state current (50 mA cm−2), power output (13.05 mW cm−2), and efficiency obtainable (≈13%) at a peculiar external load resistance (322.2 Ω) are observed during the natural sunlight illumination.