Techno-economic assessment of photovoltaic and wind powered reverse-osmosis water desalination system for rural areas in Djibouti: Comparative analysis

The over exploitation of Djibouti's rural areas coastal aquifer has facilitated the intrusion of a progressive fluctuation of water salinity. Despite the wide range of renewable energy sources, the country spends a huge sum of money to import electricity. With the economy development the country faces regularly energy shortage. This is a major barrier to foreign investments in manufacturing sector and water desalination process which is known to be an energy incentive process. Therefore, this thesis firstly assessed the engineering feasibility of the photovoltaic reverse-osmosis desalination system for three wells in Djibouti's rural areas. Thus, the system sizes, RO power requirement, as well as the required energy to run the system have been estimated. Furthermore, the financial analysis of the specific well water cost has been estimated using Bilton and Helal's models. In addition, the cost impact has been studied by comparing the obtained results with the one found using Jones's methodology. Secondly, the study carried out a techno-economic comparative analysis considering three different energy technologies to power reverse osmosis system; PV, Wind and Diesel. Finally, the study has also estimated the required area and associated cost with a forecasting construction of a small-scale suitable power plant. The estimated results clearly demonstrate that the solar PV electricity generation system have the potential to meet the selected areas electricity needs for powering reverse osmosis desalination system. Furthermore, the estimated specific water cost using PV and Wind energy was fitting with the literature results. However, the results showed that the PV, Diesel generator and wind power pumping for powering the desalination system are comparable in cost. However, despite of the lowest cost of the diesel fuel and its lower initial capital cost, the projected carbon dioxide emission remains harmful to the environment. Apart from many other advantages PV and Wind technologies offers, these technologies offer a very competitive technical and economical application in water distillation and pumping system in Djibouti.