An analysis of input choice, input prices, and environmental factors on the costs of seawater reverse osmosis systems

This paper examines optimal input allocations in the context of a seawater desalination reverse osmosis (SWRO) system used to produce municipal water. The objective of this research is to better understand the effects on the total costs and the input portfolio of a SWRO system from changes in water quality, daily operations schedule, and input prices. A cost-minimization model is developed, a production function is estimated, and sensitivity analyses are conducted. The results indicate that lower total system costs are associated with warm-weather water quality parameters and lower input prices. Conditional findings indicate a range of system characteristics that yield, in optimality, moderate levels of both capital and hourly operations. This finding is due to the substitution between capital and daily-hours of operation. Additionally, an interruptible (or off-peak) electrical power supply regime is evaluated and determined to contribute to lower system costs under realistic conditions.

► A cost-minimization model for a seawater reverse osmosis system is developed.
► A production function is estimated from pilot data.
► Warm-weather water quality parameters and lower input prices yield lower system costs.
► A range of system characteristics yield moderate levels of both capital and hourly operations.
► Interruptible or off-peak power yields lower system costs under realistic conditions.