Abstract
Buildings have been identified as significant energy users globally. Energy retrofits potentially have a substantial impact on reducing building energy use. The study employs systematic literature review and a case study as forms for data gathering. It presents a method based on performance, operation, equipment and technology efficiencies referred to as (POET) framework for holistic identification of energy saving opportunities in a commercial building. This method is applied to a case study in a commercial building located in South Africa. The work presents a POET framework guided approach to identifying and evaluating the potential energy saving projects on financial, environmental and complexity metrices. All the energy saving opportunities (ESOs) promised some reduction in carbon dioxide (CO2) emissions, they also had positive net present value (NPV) values and their payback period (PBP) were a fraction of their useful lives. The seven ESOs that were identified promise a total monthly energy saving of 163 754.22 kWh, which is 85% of the current monthly consumption. The ranking of the ESOs indicated that ESO 1, 2 and 3 which represents the installation of timer switches on hydroboils, change of lights to LED, and installation of occupancy sensors could be prioritized immediately with marginal investment to realize 7.4% monthly energy savings, while ESO4, 5, 6 and 7 representing Installation of solar PV, VSD controlled inverter rated motors, power factor correction, and building management system can be planned for considering the relatively higher complexity and investment requirements.
The practical implications and recommendations emanating from this study are the significant energy reduction potential up to 85% in monthly energy consumption, financial viability, immediate implementation priorities, long-term strategic planning for high-cost interventions, and environmental benefits. The success of the POET framework demonstrates its potential as a replicable and scalable method for commercial buildings seeking to enhance energy efficiency, achieve cost savings, and support environmental sustainability, and its application is recommended to optimise energy consumption of any commercial building.