Daniel Yamegueu

Solar-powered irrigation is expanding across the Sahel, yet a lack of field-compatible health metrics for LiFePO4 batteries limits predictive maintenance in decentralized systems. Coulombic Efficiency (CE) is unreliable under natural temperature and humidity fluctuations, thus masking early degradation. This study introduces Qcycle, the total capacity per charge-discharge cycle (QC + QD), and validates its robustness relative to CE under Sahelian semi-field conditions. Four 280 Ah LiFePO4 cells were cycled over five months (May–September 2022) in Kamboinsé, Burkina Faso, spanning dry and rainy seasons. Two regimes represented agricultural use: rapid 24-h cycles (146 total) and slow 96-h cycles (35 total). While CE oscillated erratically, Qcycle revealed consistent exponential capacity fade. Nonlinear regression yielded high goodness-of-fit values (R2 = 0.97 to 0.99), demonstrating the ability of Qcycle to consistently capture the observed degradation trend across the tested cells and cycling regimes. Qcycle provides a practical, instrumentation-tolerant alternative to CE for decentralized solar irrigation, supporting predictive maintenance in the water-energy-food nexus and advancing SDG 7 targets.

The objective of this study is to assess the potential effects of climate change on water inflows, storage, and withdrawals from the Bagré dam in Burkina Faso. This dam is multipurpose, particularly for agricultural and hydropower production. Climate change, specifically shifts in temperature and precipitation, affects water resources and can therefore disrupt hydropower generation and agricultural production. A better understanding of its effects can help in implementing mitigating measures. To this end, a random forest model was developed to evaluate the impacts of projected climate change on reservoir inflows, storage and water needs. The results show a temperature rise of 1 °C to 5 °C and a general increase in rainfall of up to 50% for the MeanEns model by 2100, compared with the reference period 1995–2014. These changes in climate variables lead in an increase in dam inflows of up to 200% in some months, compared with the reference period, an increase in water storage of up to 60%, and a rise in water withdrawals for agriculture and hydropower of up to 50% and 100% respectively. The performance of the developed model is satisfactory for simulating water inflows and withdrawals for both irrigation and hydropower generation. Given the projected increase in agricultural and hydropower water demands, it is crucial to identify effective strategies for the sustainable and efficient management of water resources at the Bagré Dam.

Access to electricity remains a major challenge in sub-Saharan Africa, particularly in rural areas where grid extension is often costly and unviable. Standalone photovoltaic (PV) and/or wind power systems with battery storage represent a promising solution, yet they still face technical and economic barriers, especially related to sizing and storage costs. This paper proposes an innovative methodology for the selection and optimal sizing of such systems, integrating a predictive battery aging model based on the analysis of real charge/discharge cycles using the Rainflow algorithm and Miner’s rule. The methodology relies on four main techno-economic performance indicators: the Loss of Power Supply Probability (LPSP), the Levelized Cost of Energy (LCOE), the Capacity Factor (CF) of a wind turbine, and the Weighted Index of Complementarity and Productivity (WICP). It accounts for available resources, the user’s hourly consumption profile, and local climatic conditions. The methodology is applied to a rural site in Nagréongo, Burkina Faso. The results show that only a PV/battery system is technically and economically viable, while wind and hybrid configurations are excluded due to low wind potential, as indicated by CF and WICP values below acceptable thresholds. Furthermore, the analysis demonstrates that the optimal system configuration strongly depends on the hourly consumption profile, even for identical daily energy demands. Finally, comparison with the classical intuitive sizing method and the widely used HOMER Pro software shows that the proposed approach reduces the LCOE by more than 50% and about 20%, respectively, by accurately accounting for real battery aging, demand variability, and system idle periods.

Introduction: In semi-arid regions, such as the Sahel, infiltration losses in earthen runoff water harvesting ponds (RWHPs) reduce the efficiency of supplemental irrigation and aquaculture. Engineered sealing methods, such as synthetic liners, are effective but often unaffordable in rural areas. This study evaluates whether fish farming can promote natural sealing of RWHPs through biological accumulation of sediments and organic matter. Methods: A 100-day field experiment was conducted in Kamboinsin, central Burkina Faso, using twelve fish-stocked RWHPs and one unstocked control pond. All ponds were managed uniformly, and daily monitoring of water levels, rainfall, and evaporation was performed. Infiltration rates were calculated from the water balance. Statistical analysis included Mann-Kendall trend tests and paired t-tests to assess temporal and treatment effects. Results: No significant temporal trends in infiltration were observed, but fish-stocked ponds showed a 95% reduction in mean infiltration compared to the control (4.7 mm/day vs . 159.3 mm/day, p < 0.0001). Discussion: The results indicated that fish farming enhances the development of a biological sealing layer, reducing seepage losses. This finding supports integrating aquaculture into water harvesting systems as a sustainable practice to improve water retention, increase resource efficiency, and align with climate adaptation strategies in semi-arid regions. Conclusion: Fish farming is not a substitute for engineered liners but represents a promising, nature-based complement in RWHPs under resource-limited conditions. Limitations include the short monitoring period (100 days) and reliance on a single control pond, which may constrain generalizability. Further studies are required to test long-term performance and broader applicability.

Integrated aquaculture–agriculture systems are recognized as sustainable solutions to optimize resources, support livelihoods, and enhance food security in climate-sensitive Sahelian regions. In contexts like Burkina Faso, runoff water harvesting ponds (RWHPs) improve agricultural yields during the rainy season but remain underutilized for the rest of the year. This study assesses the feasibility of integrating fish farming into these ponds. Using the Waso-2 tool, structured perception interviews were conducted with 51 farmers across 17 localities. Welch ANOVA and Games–Howell tests revealed, on a scale of 20, that water insufficiency scored 16.01 among experienced farmers without additional water access as a key obstacle, while pond degradation scored 17.69 for those with water access. For motivations, income generation scored 16.24 among inexperienced farmers, whereas training opportunities scored 17.65 for experienced ones, highlighting varying priorities across strata. Farmers preferred fish farming effluents over NPK for vegetables, scoring 15.99. Some favored raw effluents for immediate use, scoring 13.91, while others preferred decanted water with dried sludge for gradual nutrient release, scoring 12.39. This study demonstrates strong farmer interest in integrated RWHP systems. Enhancing pond retention, supplementing groundwater, and providing tailored training in aquaculture practices, pond maintenance, and water management are recommended to encourage adoption.

Background: PV/diesel microgrids are getting more popular in rural areas of sub-Saharan Africa, where the national grid is often unavailable. Most of the time, for economic purposes, these hybrid PV/diesel power plants in rural areas do not include any storage system. This is the case in the Bilgo village in Burkina Faso, where a PV/diesel microgrid without any battery storage system has been set up. This power plant is composed of three diesel generators operating in parallel (two of 16 kW and one of 24 kW), coupled with a photovoltaic field of 30 kWp. It was observed that for such power plants, the grid management is not always efficient due to constantly fluctuating solar output and loads. This inconsistency in energy output raises the question if integrating battery energy storage systems could improve the grid's performance. While many studies in the literature focus on hybrid energy systems, only a few of them have tackled the optimization of existing and operational systems. Methods: This study investigated three scenarios based on the existing microgrid's characteristics: conventional standalone diesel generators, PV/diesel without battery storage and PV/diesel with a battery storage system which are the main technologies used for off-grid rural electrification in Burkina Faso. The levelized cost of electricity (LCOE) was used to assess the economic performance of each scenario, and the calculations were made using the HOMER software. Results: It was found that the best among the scenarios considered is the PV/diesel/battery configuration which has the lowest LCOE of US$ 0.524/kWh. The battery storage system for the optimal configuration has a capacity of 182 kWh with about 8 h of autonomy. Conclusions: It can be inferred from this study that a storage unit is necessary for an optimal management of a PV/diesel microgrid. Indeed, the storage unit significantly reduces the operating and maintenance costs associated with running diesel generators, as well as the excess electricity. The storage system also allows for a greater reduction in CO₂ emissions compared to systems without storage.