Maximizing Solar Energy Opportunities in Mati City with GIS-Based Site Suitability Assessment

Mati City, a coastal city in southern Mindanao, is experiencing rising energy demands. However, the city’s dependence on the National Grid Corporation of the Philippines (NGCP) leaves it vulnerable to frequent power interruptions. This growing energy demand underscores the need to explore sustainable alternatives. Given Mati City’s geographic location and high solar irradiance, solar energy presents itself as a viable solution. In line with this, the study aims to develop a Solar Energy System Site Suitability Map in Mati City, Davao Oriental, through the integration of Geographic Information Systems (GIS) and multi-criteria decision-making (MCDM) techniques, specifically, the analytical hierarchy process (AHP) and Fuzzy Overlay analysis. Three criteria were considered, particularly the technical dimension (solar irradiation), environmental dimension (land use-land cover), and economic dimension (road proximity, slope, and elevation). The study revealed that Mati City exhibits favorable solar energy system development conditions, boasting a maximum annual solar irradiation of 5.242 kWh/m²/day. Considering the three criteria, 66.64% (60,859.76 ha.) of the land surface area proved suitable for solar energy system development in the city, while 33.36% (30,459.81 ha.) was deemed unsuitable. Within the appropriate regions, there was further classification into moderately suitable (7.59% or 4,619.49 ha.) and highly suitable (92.41% or 56,240.27 ha.). The findings of this study provide a basis for future research in these disciplines to advance the renewable energy power sector. These efforts are pivotal to the country’s pursuit of a low-carbon development strategy, addressing concerns related to climate change, energy security, and accessible energy resources.