Optimal operation of reverse osmosis plant driven by solar power without batteries

Ensuring adequate supply of clean drinking water and electricity in several parts of the world continues to be a formidable challenge. In coastal areas facing this problem, desalination of sea water using Reverse Osmosis (RO) driven by solar power without batteries can be an appropriate technological solution. Variability in incident solar power is a significant operational issue. The focus of this work is optimal operation and control of the RO plant with guaranteed water purity. A steady state model is developed and validated using 'ROSA', a black-box software programme commonly used for simulating RO plants. Analysis of the optimal solution reveals that the feasible space (of available power) consists of two regions where different set of constraints are active. In one region salt concentration constraint is active and in another, the pressure constraint is active. Hence the optimal operation strategy can be implemented by active constraint control. © 2012 Elsevier B.V.