Redesigning a Solar PV Kiosk in High-Temperature Environments of Burundi, Africa

Abstract

Solar PV systems in Africa are installed in high-temperature environments ranging from 25 °C to 40 °C. Experience and the literature note that these systems frequently fail a few years after installation and require the replacement of essential components such as PV panels, inverters, or batteries. In Burundi, batteries operating in high-temperature environments with a designed shelf life of 15 years are being replaced every 4 years due to thermal runaway. The motivation of this paper was to redesign a 45 kWh/day multi-use solar PV kiosk in Ruhoro, Burundi, Africa, so as to improve its sustainability. Using original primary field data, the project calculated a mean energy demand at the Ruhoro PV kiosk of 14.50 kWh/day in 2022 and a forecasted demand of 16.50 kWh/day in 2025. The kiosk is designed to supply 20.25 kWh/day after losses, which is sufficient for the current and future demand. The paper reviewed the impact of high-temperature environments on both solar PV panels and batteries. Results indicated only a 13% reduction in power output in the solar PV panels and a 60% reduction in the shelf life of acid gel batteries from 15 years to 6 years when exposed to temperatures of between 25 °C to 40 °C. To improve the shelf life of the batteries, the paper researched different cooling technologies for batteries. These included water cooling, fan cooling, and refrigeration cooling. Using engineering modelling formulae, the paper observed that the application of a fan cooling system resulted in an improvement in the product life of the batteries by 4 years and a refrigeration cooling system by 9 years. The paper concluded that using a refrigeration cooling system in the Ruhoro solar PV kiosk was appropriate and requires an additional 5.28 kWh/day. Factoring in this additional demand, the refrigeration cooling still reduced the lifecycle CAPEX cost from USD 94,625 to USD 72,875 over a 15-year period. The inclusion of a refrigeration cooling system also improved the net present value (NPV) cost effectiveness over a 15-year period from USD—62,481 to USD 4893. This is a net profit of almost USD 5000 if a refrigeration unit is installed. The paper therefore recommends the use of refrigeration cooling systems as appropriate for high-temperature environments such as the Ruhoro solar kiosk. It concludes that the refrigeration system is a cost-effective option for long-term sustainable use for communities in Africa living in high-temperature environments.