Enhancing energy efficiency in commercial buildings in Nigeria

Abstract

Demand for electrical energy in the built environment is rapidly increasing because of the continuous rise in the standard of living, explosion in population figures, and advancement in technology leading to many more electrically powered devices. At the same time, the unit cost of electrical energy consumed is escalating, so also is the increasing global concern for the environment. There is therefore an urgent need for rational use of electrical energy in all types of buildings in Nigeria. Commercial buildings are major consumers of electrical energy and thus become a potential sector of the built environment for energy-saving. Identifying the energy-saving opportunities (ESOs) and evolving an action plan to implement these ESOs will reduce the financial burden on the operators of the commercial buildings and will certainly lead to efficient utilization of electrical energy in Nigerian buildings. This paper report on the outcome of case studies carried out on four commercial buildings with energy audit conducted and areas of energy conservation identified for efficient energy usage in commercial buildings in Nigeria. A detailed energy audit was conducted on three shopping malls to cover the air conditioning and lighting systems, and a Hotel building. That of the hotel also includes the water heating system and its kitchen appliances. The energy consumptions in three shopping malls and a hotel building were studied through field measurements of the electrical energy consumption with the use of some building services devices and appliances. The four commercial buildings so selected for the study were those that have been occupied for at least two years. This is to ensure that early teething problems have been given a good chance of being ironed out with at least 12 months of representative energy data available. The detailed electrical energy audit was performed at three shopping malls and a hotel building in the city of Minna, Niger State, Nigeria. The energy audit involved surveying the energy utilization, performing energy consumption measurement, identifying possible ESOs, and seeking what could be done to make commercial buildings more sustainable. ESOs identified by the the study includes: replacing the lighting fixtures magnetic ballast with light emitting diode (LED), optimizing natural ventilation, replacing manual lighting switches with appropriate automatic lighting switches, installing energy management system, self-power generation, and the use of evaporative coolers. The study submits that it will take a simple payback period range of between 1 – 3 years for implementing these ESOs depending on the specific technology used.