Assessment of solar resource potential and estimation of direct and diffuse solar irradiation from sunshine hours data for Eastern Zone of Tigray, Northern Ethiopia

The increasing global concerns over climate change, rising energy costs, and the need for sustainable energy solutions have intensified the demand for renewable energy, particularly solar energy, which holds significant potential in regions like Northern Ethiopia. This study aims to bridge the existing knowledge gap by providing a detailed empirical analysis of solar radiation in the eastern zone of Tigray, Ethiopia, using ground-based meteorological data from three distinct stations: Adigrat, Atsbi, and Senkata. Utilizing the well-established Angstrom–Prescott equation, Geographic Information System (GIS) for mapping solar resource potential, and detailed statistical analyses, the research estimates solar radiation levels and evaluates seasonal and spatial variations. The findings reveal that Adigrat experiences peak solar radiation in late spring, with an annual average of 6.1 kWh/m2/day, while Atsbi records the highest annual average solar radiation at 6.1 kWh/m2/day, peaking in May at 8.2 kWh/m2/day. Senkata, with its warmer and drier climate, shows an annual average of 6.0 kWh/m2/day, with peaks in March and April. The study highlights the importance of site-specific solar resource assessments for optimizing solar energy systems, such as photovoltaic (PV) and concentrated solar power (CSP), solar thermal systems and solar heating technologies. These findings have significant policy implications, particularly for rural electrification projects in Ethiopia, where solar energy can serve as a sustainable alternative to traditional grid systems. By providing detailed solar resource assessments, this research informs investment strategies and policy decisions aimed at promoting renewable energy development, ultimately contributing to energy security and sustainable development in the region.