Energy transformation of Cape Verde : establishing a 100% renewable energy mix for 2020 and 2030

Abstract

This thesis concludes that a 100% renewable energy system throughout the nine populated islands of Cape Verde is technically feasible. 2012 was chosen as the base year due to availability of consistent data. Values of 2012 and projections from the Ministry of Energy were taken to predict the size of the energy sector by 2020 and 2030. In consequence, the results are presented for these two years. Besides, the thesis is built upon a thorough literature review which provided the integral equations and processes for the assessment of potential. Furthermore, this study has been supported by the expertise of ECREEE staff as well as other experts in the field. In a first step the theoretical overall technical possibility of deploying 100% RE has been established by computing the required land area for solar PV respectively the number of wind turbines to supply the annual energy demand. It was found that Cape Verde can accommodate sufficient facilities either relying on 100% wind or solar PV. In a second step, an individual energy mix for each of the nine islands has been derived. The approach was based on a numerical analysis of hourly values for loads and the wind and solar resource. Additionally, two different energy storage schemes were applied, without which no 100% renewable electricity system can succesfully work. For this study, energy storage was designed to sustain a 1,5 day respectively a 1 week period without newly produced energy. Moreover, four distinct ways of storing excess energy were considered. All islands proved to be able to accommodate power-to-gas energy storage while only individual islands have been selected for battery, thermal energy and pumped hydro storage. The outcome indicates that solar PV is the most reliable resource in two thirds of all scenarios while wind only plays a vital role for two of the nine islands. The excess energy produced by both scenarios (1,5DS and 1WS) is extensive, however, especially for the shorter storage scheme. Finally, all scenarios have been put in a financial context. It has been deduced that costs will be vast and might prove to be an obstacle in achieving 100% RE penetration. Among all storage scenarios assessed power-to-gas storage is the most attractive one in terms of costs. Furthermore, larger sized energy storage schemes turned out to be the least cost option.