Life cycle assessment of portable charging technologies—a case study of a solar charger and a power bank

Abstract Purpose This study evaluates the potential environmental impacts of a portable single-Si solar-powered charger and a rechargeable lithium-ion polymer power bank. Subsequently, the cumulative energy demand has been calculated, which serves as a basis for indicators of the profitability of energy use. In addition, the total costs over the life cycle have been collected in order to compare the financial burden for the consumer. Methods The life cycle framework with the software openLCA was used to determine the environmental impact potential. One kilowatt hour of electrical energy was used as the reference flow. The life cycle was specified as 100 charging cycles of the power bank over a period of 4 years. The data for the life cycle inventory was collected through a combination of measurements, database research, and literature. Measurements and impact assessment were visualized in Power BI. For the impact assessment, the methods ReCiPe Midpoint (H) v1.13, ReCiPe Endpoint (H,A), and cumulative energy demand provided by ecoinvent were used. With the latter, the indicators energy payback time and energy return on energy invested were calculated. In addition, a total cost of ownership analysis was carried out to get knowledge about the lifetime costs of the compared devices. Results The study showed that in the impact assessment on the endpoint level, the scores of both devices have an overlapping confidence interval. However, the power bank is significantly beneficial in two of three areas on the endpoint level, in nine of 18 impact categories on the midpoint level, and in six of eight categories with the cumulative energy demand method. With the cumulative energy demand method, the power bank performs significantly better than the solar charger. From an energy perspective, the solar charger becomes more advantageous than the power bank after 9.98 years. The energy return on energy invested indicator is 0.40. In addition, the total cost of ownership of the solar charger is more than twice that of the power bank. Conclusions The aim of the solar charger was to have less ecological impact, but the resource-intensive production of single-crystalline silicon cells prevents an ecological advantage. On the other hand, the impact score of the power bank is also significantly increased by the cobalt cathode. In summary, regarding its environmental footprint, the power bank is equal to or even superior to the solar charger, depending on the method used.