Climate, Environmental and Dynamic Performance Assessment of a PV-Wind-Battery Mini-Grid in Tafaghatt, Niger

Abstract

This paper reassesses a 28.5 kWc PV array, a 10 kW wind turbine, and a 240 kWh (5,000 Ah/48 V, LiFePO₄) hybrid mini-grid proposed for the unelectrified village of Tafaghatt, Maradi region, Niger, moving beyond the single-day demonstrations common in this literature to a physically documented, reproducible annual assessment. Ten years (2012-2021) of NASA POWER, PVGIS and Meteorum-derived monthly climate data show limited interannual variability in reconstructed annual mean temperature (30.15 °C, range 29.98-30.47 °C) alongside two warm anomalies in 2017 and 2019, a comparatively narrow daily solar irradiation band (5.46-5.69 kWh/m²/day) and a more variable wind speed (annual mean 4.49 m/s, 4.15-4.20 m/s to 4.75-4.78 m/s across years); a ten-year record constrains only recent interannual behaviour and does not by itself demonstrate long-term climate stability. Rather than scaling synthetic daily profiles to match the design energy balance, system performance was evaluated with an explicit hour-by-hour reconstructed representative year (8,760 h), built from documented clear-sky solar geometry, a stochastic clearness-index process and Weibull-type wind variability calibrated to the established monthly climatology, and propagated through a temperature-dependent PV model, a generic cubic wind power curve, a LiFePO4 battery model with round-trip efficiency and depth-of-discharge limits, and a documented 160 kWh/day load broken down by end-use category. Under a moderate 15% soiling assumption, the reconstructed year yields an annual renewable fraction of 85.0%, a loss-of-power-supply probability (LPSP) of 15.0%, with unmet load concentrated in the July-September monsoon window when cloud cover and calm winds coincide, and 82 equivalent full battery cycles; a one-factor-at-a-time sensitivity analysis shows that LPSP responds strongly to solar resource, wind resource, demand growth and panel soiling, but only marginally to battery capacity between 150 and 300 kWh, indicating the configuration is resource-limited rather than storage-limited. An environmental and social impact assessment structured around IFC/World Bank Environmental and Social Standards (ESS4, ESS5, ESS6, ESS10) identifies avian-collision risk, battery-related contamination risk and land-tenure friction as the principal negative impacts; a point-source acoustic model indicates that the IFC night-time residential guideline (45 dB(A)) is met beyond approximately 100 m from the turbine. These results indicate that, under the assumptions documented here, the proposed configuration performs reasonably over most of the year but does not consistently meet demand through the monsoon season, a finding that could not have emerged from a single balanced-day scenario and that points to resource-side reinforcement, not additional storage, as the more promising design lever. On-site metering and manufacturer-specific component curves remain necessary before these numerical results can be treated as an experimentally validated performance guarantee.