This techno-economic evaluation and review of desalination costing aspects discusses factors that contribute to water cost variation. The impact of recent technology improvements on water cost variation is also discussed; the paper includes recent data on energy consumption and cost trends of different desalination technologies.
Desalination capacity has increased rapidly in the last decade, because of increasing water demand and reduced desalination cost as a result of significant technological advances, especially for reverse osmosis.
The cost of desalinated seawater has fallen below US$0.50 per m3 for a large scale seawater reverse osmosis plant for a specific location and conditions, while in other locations the cost could be double for a similar facility.
In addition to capital and operating costs, other parameters such as local incentives or subsidies may also contribute to the large difference in desalted water cost between regions and facilities. Plant suppliers and consultants have their own cost calculation methodologies, but they are confidential and provide water costs with different accuracies.
The few existing costing methodologies and software packages – such as WTCost© and DEEP – provide an estimated cost with different accuracies, and their applications are limited to specific conditions. Most of the available cost estimation tools are of the 'black box' type, which provide few details concerning the parameters and methodologies applied for local conditions.
Many recently built desalination plants have greater desalinated water delivery costs caused by special circumstances, such as plant remediation or upgrades, local variations in energy costs, and site-specific issues in raw materials costs (e.g. tariffs and transportation).
Therefore, the availability of a more transparent and unique methodology for estimating the cost will help in selecting an appropriate desalination technology suitable for specific locations, considering all of the parameters influencing the cost.
Researchers in Saudi Arabia present here a detailed techno-economic evaluation and review of the costing aspects and the main parameters influencing the total water cost produced by different desalination technologies.
Some recent developments, such as increased unit capacity, improvements in process design and materials, and the use of hybrid systems, have contributed to cost reduction as well as reduced energy consumption.
The development of new and emerging low-energy desalination technologies, such as adsorption desalination, will have an impact on cost variation estimation in the future.
