Optimising residential electricity demands through innovative demand side management strategies in Nigeria

The Nigerian power supply faces significant shortages, resulting in frequent nationwide power outages, load shedding and severe energy crises. The country relies heavily on a centralised energy mix, primarily comprising gas-fired power plants with a capacity of 10.6 Giga Watt (GW) and hydropower with a capacity of 1.9 GW. Despite having a total installed capacity of 12.5 GW, only around 4 GW actually reaches end consumers. This is mainly due to limited transmission infrastructure, inadequate distribution facilities, poor metering, inadequate fuel supply, lack of market competition and inadequate management of energy resources. Innovative demand side management (DSM) strategies are required to optimise electricity demands at customer ends to improve the power supply in Nigeria. This thesis develops an innovative DSM method of utilising direct load control (DLC), acting as a mandatory operational strategy for regional residential grids, as opposed to traditional approach of load shedding. The proposed DLC method controls residential loads by classifying loads into three different categories: critical, less critical, and non-critical. The evaluating metrics include energy cost savings and comfort levels of residence (i.e., the length of supply of the critical loads). Furthermore, paper-based surveys are used as the quantitative methods to evaluate the understanding, awareness, and attitude of Nigerian households towards DSM under different representative groups. The survey data are also used to model load profiles, to which the DLC is applied to validate the proposed DLC method. The proposed DLC method was compared with load shedding considering three load shedding scenarios: 1) nobody uses generators during power cut period, 2) running home generators for 4 hours per day during power cut period, and 3) running home generators for 8 hours per day during power cut period. Simulation results showed that, for scenario 1, the proposed DLC method results in a 20% of energy cost saving and a 28% improvement of in comfort level; for scenario 2, the proposed DLC method results in an 87% decrease in household expenditure and a 5% decrease in comfort level, and for scenario 3, the proposed DLC method results in a 93% energy cost saving but a 39% decrease in comfort level. The study shows that households with the post-paid billing systems are less responsive to the DSM approach. However, the proposed DLC strategy results in higher cost savings on the post- paid billing systems (23%) than the pre-paid billing systems (17%), both compared to the load shedding approach. Households working in the public sector who use the pre-paid billing system have proven to be the most effective target group for implementing DSM. This is because these households consume 23% more energy on average compared to other representative household groups. This research presents an innovative DLC method designed to enhance power supply in residential grids, providing an alternative to load shedding in developing countries. Additionally, it utilises a methodology that involves gathering data through paper-based surveys to construct electricity demand profiles, establishing a numerical dataset for future DSM studies. The research findings reveal that the proposed DLC method not only lowers energy expenses but also improve overall household comfort and quality of life.