Solar energy harvesting-based built-in backpack charger

Abstract

Developing renewable energy sources has gained considerable attention recently. Solar energy is the fastest-growing alternative renewable energy source. A solar energy harvesting-based built-in backpack charger is introduced here. The proposed system aims to utilise the surrounding solar energy and overcome the power limitations of batteries installed in mobile phones in cases where power sockets are unavailable. A 6 cm × 6 cm solar module is employed. Additionally, current, voltage, and power were measured under the two scenarios; the first scenario is when the electrical load is 100 Ω, and the second scenario is when the load is a power bank. The maximum harvested power noticed in the first scenario of the resistive load was 140 mW by the proposed system in the southeast direction from 10:30 a.m. to 4:30 p.m. Moreover, the top-generated output voltage and current in this scenario were 3.6 V and 36 mA. On the other hand, 55 mW was the top value for the second scenario of the power bank as a load in the flat direction with the highest generated output voltage and current of 4.1 V and 13 mA, whereas 4.27 V was the highest generated voltage in this scenario in the west direction.