Pathways for integrated concentrated solar power - Desalination: A critical review

Concentrated solar power (CSP) plants provide the means to generate dispatchable, renewable electricity in high direct normal incidence (DNI) locations around the world. Due to the strong inverse correlation between DNI resources and freshwater resources, most of the best potential CSP sites also lack sufficient freshwater resources. Thus, an attractive natural symbiotic pathway exists for developing CSP plants integrated with desalination (D) technology, particularly for sites in proximity to large bodies of salty water (e.g., seawater or saline groundwater). As such, this review critically explores the potential for five CSP-D designs proposed in the literature. Overall, this critical review compares and contrasts the major integration designs on the basis of common merits and limitations. A key finding of this review is that the choice of the most feasible CSP desalination integration is not a straightforward process. It was found that the details surrounding where energy extraction takes place from the CSP cycle can make a significant impact on the feasibility of the plant. In general, waste heat coupling and electrical-driven reverse osmosis integration were found to provide the best technical and economical results. However, no clear-cut ‘winning’ design could be concluded from this review. In fact, the water and energy losses of the condenser were found to significantly shift the results between the two designs. As such, we hope that this review will help guide researchers and engineers towards CSP-D development which has the highest chance of commercial uptake.