CURRENT STATUS AND OUTLOOK OF RENEWABLE ENERGY DEVELOPMENT IN NIGERIA

Over 80% of the current Nigerian primary energy consumption is met by petroleum. This overdependence on fossil fuels derived from petroleum for local consumption requirements should be a serious source of concern for the country in two ways – depletion of the resources and negative impact on the environment. This paper presents a critical review of the available renewable energy resources in Nigeria, namely; biomass, hydropower, solar and wind energy. It examines the current energy situation in the country and equally discusses the various energy policy documents developed by the government. Using the scenario-based International Atomic Energy Agency models, the projected energy demand and supply structure of the country through 2030 are presented and analysed. Overall, this study shows that Nigeria will overcome her present energy crisis if she explores the abundant renewable energy resources in the country.  The data presented in this paper is a crucial eye-opener for relevant government agencies towards developing these energy resources in tackling the present energy crisis in Nigeria.  http://dx.doi.org/10.4314/njt.v36i1.2

Optimal Power Flow Analysis in Power Dispatch for Distribution Networks

This paper presents two applications of Optimal Power Flow analysis for active and reactive power redispatch in medium-voltage distribution networks and shows how this tool can be used to efficiently manage the selection and operation of network resources as well as the definition of a market interface with the transmission network. The description of the frameworks is complemented by the analysis of a case study for the optimal selection and operation of available devices

Stable Integration of Power Electronics-Based DG Links to the Utility Grid with Interfacing Impedance Uncertainties

Part 16: Energy: Power Conversion IIInternational audienceFor the integration of distributed generation (DG) units to the utility grid, voltage source converter (VSC) is the key technology. In order to realize high quality power injection, different control techniques have been adopted. However, the converter-based DG interface is subject to inevitable uncertainties, which adversely influence the performance of the controller. The interfacing impedance seen by the VSC may considerably vary in real distribution networks. It can be observed that the stability of the DG interface is highly sensitive to the impacts of interfacing impedance changes so that the controller cannot inject appropriate currents. To deal with the instability problem, this paper proposes an enhanced fractional order active sliding mode control scheme for integration of DG units to the utility grid, which is much less sensitive to interfacing impedance variations. A fractional sliding surface which demonstrates the desired dynamics of the system is developed and then the controller is designed in two phases: sliding phase and reaching phase to keep the control loop stable. The proposed controller takes a role to provide high quality power injection and ensures precise current tracking and fast response despite uncertainties. Theoretical analyses and simulation results are verified to study the performance and feasibility of the proposed control scheme