Environmental Impact of Solar Home Systems in Sub-Saharan Africa

Abstract

Solar home systems (SHS) represent one of the most promising technologies for a rapid and independent electrification in those areas of Sub-Saharan Africa (SSA) without access to electricity. This study addressed the environmental impact of SHS in SSA through updated life cycle inventories and five impact categories: greenhouse gases (GHG) emissions, fossil fuels, metal and water depletion and human toxicity. Sixteen scenarios were considered, including manufacturing, transportation, recycling and user-related variables, such as the installation site, adequacy of SHS user operation and battery lifespan. The results showed that lead-acid batteries were the largest contributor to environmental impact among the SHS components, accounting for up to 36–76% of the environmental impact indicators. Apart from the components, user training for SHS operation, with the goal of maximizing usable energy and battery lifetime, proved to be critical to achieve improvements in the energy payback time and GHG emissions, which (under scenarios of high solar resources) can reach the range of 5.3–7.1 years and 0.14–0.18 kgCO2 eq/kWh, respectively. In addition, SHS GHG emission factors were benchmarked with those of other electrification approaches, such as national grids, 100% PV and hybrid PV-diesel off-grid mini grids and off-grid diesel generators. SHS achieved GHG emission factor values equivalent to PV-based mini grids in most scenarios and was strikingly lower compared to SSA national grids and diesel generators.

Solar E-Cooking with Low-Power Solar Home Systems for Sub-Saharan Africa

“…The cooking potential was calculated based on the excess of energy of the SHS after discounting the non-cooking electric requirements. Two SHSs were considered based on markets trends of SHS in SSA [39]: SHS100 and SHS150, which integrate a 100 and 150 Wp poly-crystalline PV modules, respectively, with a deep-discharge lead-acid battery of 100 Ah (C10) and a pulse-width-module (PWM) charge regulator and which operate at 12 V DC without an inverter. Two different e-cooking devices were analyzed: a rice cooker (100 W, 12 V DC) and a slow cooker (96 W, 12 V DC) (Figure 2).…”

“…The cooking potential was calculated giving priority to non-cooking electricity use until BMDP was reached. The electricity demand curve for non-cooking purposes was estimated considering the widely referred SHS evening peak demand curve [39,48], assuming two LED light bulbs (at 5 W each during 3 h), two phone chargings per day (at 4 W each during 1 h), and an undefined electric device (at 40 W during 1 h). Then, a cooking operational window was considered assuming three potential cooking periods related to three food daily intakes (one for the tea breakfast and the other two for the meal intake): 7:00-9:00, 10:00-14:00, and 16:00-18:00 (local standard time) assuming a cooking energy expenditure of 45 Wh per 220 g. Eventually, the daily energy consumption for H2, H5, and H8 were 258, 483, and 708 Wh/day, respectively.…”