Integrated Energy and Water Planning on an Arid Island, Case of S. Vicente, Cape Verde

In general, most islands depend for energy supply mainly on the imports of fossil fuels. Arid islands also depend on water desalination, again often depending on fossil fuel imports. On the other hand, most of the islands present a considerable potential in renewable energies. Several initiatives have been carried out in some islands, mostly in Europe, for the use of this potential in the production of electricity and fresh water. Due to high energy costs, the islands present an excellent experimentation platform for the introduction of new energy technologies. Some islands are trying to become renewable islands, to satisfy their energy and water demand mainly or entirely from indigenous and renewable sources, thus increasing the security of supply and employment opportunities, without necessarily increasing the costs. Islands that have renewable energy sources, such as hydro or geothermal energy, can easily integrate them into the power system, but those with mainly intermittent renewable energy sources (wind, solar) have to tackle the need of energy storage. Here, advanced energy planning must be used to combine different intermittent and regular sources in order to match electricity demand and assure security of supply. The main objective of this paper is to analyse different scenarios for increasing the penetration of renewable energies in the energy system of S. Vicente Island in Cape Verde, using the H2RES model, a tool designed to simulate the integration of renewable sources in the energy systems of island or other isolated locations. This island is extremely dry, and fresh water is provided to the population by sea water desalination, a very high energy intensive process. The electricity supply system is based on diesel and wind (still low penetration). S. Vicente has significant wind resources that are not fully used because of its intermittent nature. In this paper, an integrated approach is used to analyse the electricity and water supply systems in order to increase their efficiency. In the centre of the island there is a 774 meters high mountain. The present study incorporates the possibility of using reversible hydro as a storage technique to increase the penetration of renewable energy sources, using desalinated sea water.