A flexible techno-economic model for the assessment of desalination plants driven by renewable energies

One of the major difficulties in the assessment of costs of desalination projects is that key investment parameters and operation-related parameters are project-specific data. This information is commonly not in the public domain and is generally available only to the general contractor. In addition, the interpretation of published data is complicated by the fact that often plant boundaries are not clearly indicated (e.g. if the intake cost and the pipeline cost to and from the plant are included in the evaluation). Finally, the analysis involves an elevate number of design parameters, such as plant capacity and configuration, metal and other material prices, and very site-specific conditions (seawater quality, feed water intake, and brine discharge). In the end, these issues result in difficult comparability of data from different sources about the cost of the desalinated water. This paper deals with the implementation of a flexible techno-economic model for the assessment of desalination plants on system analysis level. Thereby, the focus is given to units driven by different technologies (conventional steam turbines and concentrating solar power). The model is applied in a case study in order to evaluate and compare the performance and the costs of different desalination technologies (multiple effect distillation and reverse osmosis). Finally, a sensitivity analysis of the results with respect to selected key design parameters is carried out.