1. Introduction

Africa needs to significantly improve its electricity supply in order to enhance energy access for its growing population and provide the means for economic growth. Africa has great domestic renewable energy potential, which could be used to provide much needed energy in an affordable and secure manner, and to contribute to universal access to modern energy while avoiding negative environmental impact. A long-term vision is needed to make the best use of available domestic resources, given the long-lasting nature of energy infrastructure. Since different power supply technologies have different operational characteristics that could complement each other, the deployment of renewable technologies cannot be planned in isolation from the rest of a power system, but rather needs to be looked at from the perspective of their integration into the system.

The International Renewable Energy Agency (IRENA) aims to assist its member countries with energy system planning to make a transition to an energy system that makes maximum use of environmentally benign, fossil-free renewable technologies. IRENA's earlier work Scenarios and Strategies for Africa was a major input to the IRENA-Africa High Level Consultations on Partnership on Accelerating Renewable Uptake for Africa's Sustainable Development, held in Abu Dhabi in July 2011, at which Ministers of Energy and heads of delegation of African countries announced a communique recognising the IRENA's role in promoting renewable energy to accelerate Africa's development (IRENA 2011a).

IRENA has since taken up a number of research projects to provide a solid factual basis supporting policy decision-making. This report presents some of the energy system planning scenarios for the ECOWAS (Economic Community of West African States) region, which describe a long-term (i.e., till 2050) transition to a renewable-oriented future of national power systems in the region. This can be accelerated by taking into consideration the long-term cost-reduction potential of renewable energy technologies. Technically feasible and economically favourable transition paths were computed by an energy system modelling tool called EREP (ECOWAS Renewable Energy Planning tool), in which retirement of current power infrastructure, geographical distribution of renewable resources, generation adequacy of the system, among others, were taken into account. The assessment includes economic and social implications of adopting renewable energy, in terms of investment needs, fuel savings, energy savings, etc. This is a part of series of activities that IRENA has been conducting for all five power-pool regions in Africa, covering all continental African countries.

The EREP model is built on the database of the West African Power Pool (WAPP) system, which consists of existing generation units, international transmission lines and a range of future technology options. EREP calculates future configurations of the power system based on specified system requirements and to meet given, or fluctuating, energy demand. The configuration of the power system is defined primarily by achieving the minimisation of total energy costs over the planning period (i.e., 2010 - 2050).

WAPP recently published the Draft Final Report of the Update of the ECOWAS Revised Master Plan for the Generation and Transmission of Electrical Energy (WAPP, 2011), in which different power generation and transmission projects are analysed and evaluated from an economic and technical perspective. The economic evaluation of different planning scenarios, combining different policy actions and uncertainties was done using a power system optimisation tool. The WAPP Master Plan uses these scenarios to identify priority investment projects from a techno- economic perspective.

For this study, the reference scenario of the WAPP Master Plan was recreated using the EREP model, in order to show the compatibility of the EREP model approach with the WAPP Master Plan's underlining approach. This study's primary value addition is that insights from IRENA's latest analytical work on renewable technology development and renewable resource potentials are reflected in the database and modelling approach. The renewable scenario presented in this report shows that a more aggressive deployment of renewable technology than the one in the WAPP Master Plan reference scenario is feasible and even economical. Its secondary additional value is that the EREP model is built on a modelling framework that is well maintained and can be obtained free of charge. EREP is designed to be transferred to interested organisations in IRENA Member Countries so that they can use it to explore alternative scenarios for national and regional power sector development. Regional training programmes could also be organised upon request. Several EREP model tutorials have been developed by IRENA and ECREEE and made available at www.irena.org/WAPP.

EREP covers all the continental ECOWAS countries: Burkina Faso, Cote d'Ivoire, Gambia, Ghana, Guinea, Guinea-Bissau, Liberia, Mali, Niger, Nigeria, Senegal, Sierra Leone, and Togo/Benin.