GIS-Based Photovoltaic Power Plant Siting Using Energy Production and a Demand Coverage Index

The siting of utility-scale photovoltaic power plants requires the joint assessment of spatial feasibility, photovoltaic productivity, and electricity-demand conditions. This study proposes a two-stage GIS-based decision-support framework that separates the identification of a preferred photovoltaic site within each study area from the subsequent energy-demand assessment of the selected alternatives. In the first stage, spatial screening excludes protected areas, hydrographic restrictions, urbanized areas, incompatible land uses, and areas that do not satisfy the minimum contiguous land requirement. Proximity to suitable existing electrical infrastructure is then used as a strategic criterion to identify a preferred georeferenced photovoltaic location within each study area. In the second stage, the selected locations are evaluated according to location-specific photovoltaic power output, expected annual photovoltaic energy production, and a Demand Coverage Index (DCI). The methodology is applied to five study areas in Ecuador—Santa Elena, Catamayo, Manta, Quito, and Guayaquil—considering a standardized 100 MW photovoltaic plant. Expected annual photovoltaic energy production ranges from 125,210 to 159,560 MWh/year. Quito exhibits the highest annual photovoltaic energy production, whereas Catamayo achieves the highest DCI (0.4181), indicating that the estimated annual photovoltaic generation represents approximately 41.81% of the annual electricity demand associated with its distribution area. After normalization of photovoltaic energy production and demand coverage and the application of equal weights, Catamayo achieves the highest composite siting score (0.9847), followed by Santa Elena, Quito, Manta, and Guayaquil. The results demonstrate that maximizing photovoltaic energy production alone does not necessarily lead to the highest-ranked alternative when electricity-demand coverage is also considered. The proposed framework provides a transparent approach for integrating geospatial feasibility, photovoltaic productivity, and demand-oriented criteria in strategic utility-scale photovoltaic planning.