Design, Fabrication, and Experimental Performance Evaluation of a Low-Cost Vertical-Axis Wind Turbine-Photovoltaic Hybrid System for Rural Electrification in Northern Nigeria

Reliable electricity remains inaccessible to many rural communities in Nigeria due to inadequate grid infrastructure and the high cost of conventional energy systems. Hybrid renewable energy systems that combine wind and solar resources provide an effective alternative for decentralized electricity generation, particularly in regions with complementary renewable energy profiles. This study presents the design, fabrication, and experimental evaluation of a low-cost vertical-axis wind turbine (VAWT) integrated with a photovoltaic (PV) subsystem for rural electrification in northern Nigeria. The prototype consists of a three-bladed H-type Darrieus VAWT employing a NACA 0021 symmetrical airfoil coupled to a permanent-magnet alternator and a 300-W photovoltaic module through a battery-supported hybrid energy management system. Performance testing was conducted under wind speeds ranging from 2.8 to 6.5 m s⁻¹ and solar irradiance between 420-910W m⁻² in Mubi, Adamawa State, Nigeria. Wind speed, rotor speed, voltage, current, and solar irradiance were continuously monitored using calibrated sensors connected to an Arduino-based data acquisition system. Experimental results showed that the turbine attained a cut-in wind speed of approximately 2.8 m s⁻¹ and produced a maximum electrical output of 68.4 W at a wind speed of 6.5 m s⁻¹, corresponding to an overall electrical conversion efficiency of approximately 29.3% and a power coefficient within the expected operating range for small H-rotor VAWTs. The hybrid configuration generated an average daily electrical energy of approximately 3.2 kWh, improving power availability during periods of low solar irradiance through complementary wind generation. The total fabrication cost of approximately ₦1.50 million demonstrates the economic feasibility...