Sustainable energy and infrastructure technologies in university campuses: A cross-technology comparative analysis

University campuses are becoming increasingly important spaces for the implementation of sustainable infrastructure technologies. The current study investigates four major technology categories towards campus sustainability; green roofs, photovoltaic (PV) systems, hybrid renewable energy systems and smart monitoring platforms, through a combined bibliometric and systematic qualitative review of twelve studies. Relevant publications were retrieved from the Scopus database for the period 2015–2024. Study selection and screening were conducted using the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines and Population, Intervention, Comparison, Outcomes, and Study Design (PICOS)-based eligibility criteria. The bibliometric mapping technique using VOSviewer shows that sustainability and energy management are the dominant research trends, while integrated green roof applications and smart monitoring systems remain comparatively underexplored. Results showed reported PV energy coverage ranged from approximately 35–100% of campus electricity demand in specific cases, depending on climatic conditions and system characteristics, and the grid-connected hybrid systems achieved a levelized energy cost as low as 0.072 USD/kWh with payback periods of about 5 years. Smart monitoring approaches detected performance losses up to 32% due to undetected PV module faults. The study further indicates that most of the studies included were mainly based on conceptual or simulation-based approaches with limited validation of long-term operational performance at the campus scale. The study generally shows significant differences in the reporting of key technical, environmental and economic indicators such as annual energy generation, energy coverage, carbon offset, LCOE and techno-economic performance indicators. These inconsistencies limit comparability between studies and raise the need for standardized and integrated sustainability assessment frameworks to support evidence-based campus sustainability planning.