It is necessary to specify that this study is an academic work carried out by a student as part of his master's project. The hypotheses and reasoning made by the student are at the origin of the results obtained. Energy has a crucial role in the economic development of a nation or region. The states of ECOWAS, have decided to come together to unite for this challenge and offer quality services to the population. WAPP, a specialized institution, decides to interconnect networks in order to pool the resources of the electricity market and offers quality access at a competitive price to the population. It is therefore necessary to strengthen production, distribution and transmission capacities to ensure the coordination of electricity exchanges between member countries. This study initially consisted in setting up a methodology explaining the progressive approaches that are applied throughout the project. The strategies for expanding the fleet are each analysed: the self-sufficiency strategy including existing imports and bilateral agreements, the strategy applied by WAPP along with variants involving the share of local production for importing countries. The expansion analysis is done with the support of the PlanElec software. An economic and technical comparison is then made on these two strategies, based on the different costs, the different investments, the installed powers by type and the energy produced. It can be seen that the more the share of local production increases for importing countries, the more interesting the weighted cost of production becomes. But this has a limit demonstrated by the autarkic strategy. Indeed, the countries considered as importers use imports and their weighted cost of production is lower than with a local production share imposed. From a global economic point of view, it is more interesting to rely on the major energy powers of the sub-region. With this study, it has been shown that it is more interesting for countries to turn to an open market policy, dependent on the major powers of the region, although politically no country wishes to be totally dependent on another.