Techno-economic assessment of solar energy coupling with large-scale desalination plant: The case of Morocco

This paper examines the cost competitiveness of an extra-large-scale (275,000 m3/d) solar-powered desalination, taking as a case study the Chtouka Ait Baha plant in Morocco. It assesses the conditions at which solar Photovoltaics (PV) and Concentrated Solar Power (CSP) would be competitive with a grid (mainly fossil) driven desalination plant for the reference year and by 2030. The paper considers also a scenario where battery storage complements PV power generation. To conduct the analysis, a simple model of water cost calculation is built. Second, the cost related to energy consumption is calculated for different power supply options to evaluate the impact of energy provision cost on the final cost of water. The first main result of this paper is that desalinated water can be obtained at an acceptable cost of around 1 $/m3. The second one is that PV without storage remains the cheapest power supply option today and by 2030. Storage based solution appears less competitive today but can be more attractive in a framework of increasing electricity grid prices and higher flexibility requirements in the future. The paper gives recommendations regarding the implication of different technology choices in the framework of the future Moroccan energy system.
Highlights • A water cost model for a Reverse Osmosis (RO) unit is developed. • A general methodology to assess the impact of power supply in the final cost of water is proposed. • Power supply options including the grid, solar technologies and storage are compared in the case of a RO plant in Morocco. • PV powered RO without storage is the most cost competitive design for large-scale units. • CSP powered RO and PV powered RO with batteries are expected to become attractive by 2030.