Energy audit, techno-economic, and environmental assessment of integrating solar technologies for energy management in a university residential building: A case study

This study presents the results of an energy audit and management performed on a university residential building in Borg El-Arab City, Egypt. The building’s energy consumption, areas of energy wastage, and energy-saving opportunities were investigated, and the corresponding energy metrics were quantified accordingly. Firstly, an energy consumption is estimated based on the building's electricity bills, meter measurements, and survey. Then, the energy consumption is analyzed and evaluated. Subsequently, the feasibility of integrating solar technologies (i.e., photovoltaics and domestic water heating) into buildings is appraised from techno-economic and environmental perspectives. The study employs ASHRAE Level 1 and 2 guidelines for conducting energy audits. The results show that electricity consumption is highest in air conditioning units (which consume ∼62%), followed by socket loads (∼25%), and lastly, lights (∼13%). Detailed analysis of the energy-use characteristics of the building revealed the mismanagement of electricity. Through light retrofits such as replacing the incandescent bulbs with LED bulbs, adopting sensory lights, and delamping, the building would save 4,432.6 kWh annually. Additionally, changing the AC unit type from non-inverter to inverter type would save approximately 61,194 kWh/year, representing 22.96% energy savings, with a payback period of 8.6 years. Overall, the proposed energy conservation measures will mitigate 30.8 tons of CO2 per year. Furthermore, incorporating PV and SWH systems will lead to annual energy contributions of 79,820 kWh and 38,048 kWh, with payback periods of 3.77 years and 2.49 years, respectively. Notably, the solar technologies will altogether abate approximately 91.5 tons of CO2 and provide a carbon credit gain of $1,830 annually.