Geospatial assessment of electricity demand and rooftop solar PV capacity in FUTA academic buildings

Abstract

This study analysed electricity demand patterns in academic buildings of the Federal University of Technology, Akure (FUTA), and assessed rooftop solar photovoltaic (PV) potential as a sustainable energy supply option. A hybrid methodology was applied, combining facility classification, equipment ratings, empirical demand calibration, questionnaire-based operational schedules, and geospatial analysis. Rooftop areas were derived from high-resolution UAV Orthophotos (4.36 cm) digitised in ArcGIS Pro across 93 building footprints. Data from 387 respondents, complemented by field audits, revealed two dominant demand regimes: daytime peaks in offices, classrooms, and lecture halls, and extended evening peaks in laboratories, libraries, and computer laboratories. Calibration of theoretical load ratings against actual measurements produced a mean demand factor of 4.23%, indicating significant overestimation when relying solely on unadjusted equipment ratings. Laboratories, computer laboratories, and offices accounted for over 73% of monthly electricity use. Rooftop assessment showed that 33.32% of the total roof area (32,938.66 m²) is suitable for PV installation, with an estimated weekly generation of 115,096.26 kWh; over five times the actual weekly demand of 18,831.40 kWh. This surplus highlights the feasibility of achieving net-zero operation for low- and medium-demand facilities, while substantially offsetting loads in high-consumption buildings. Findings provide a replicable framework for sustainable campus energy planning in Nigeria and similar contexts. Results should, however, be interpreted cautiously, as demand factor generalisation, rooftop correction factors, averaged solar inputs, and exclusion of residential and utility facilities limit comprehensive campus-wide applicability.