Systematic design of a wind-driven reverse osmosis desalination plant for Arar City, Saudi Arabia

Systematic design of a wind-driven reverse osmosis desalination plant is proposed. The desalination plant should supply 2,592 m(3)/h of potable water to the inland arid city of Arar in the Kingdom of Saudi Arabia. For an annual average wind speed of 4.07, the numerical simulation indicated an optimum specific energy consumption occurs when the desalination plant operates at a 0.65-0.75 recovery ratio. The corresponding plant structure at this optimum condition comprises of 22 wind turbines and 500 membrane vessels. However, this plant failed to provide the city with enough water demand over a full year with an annual deficit of around 2,480-2,670 m(3)/h because the monthly average wind speed fluctuates. Redesigning the plant structure using grid search over wind speed resulted in an optimum plant operation at a 0.75 recovery ratio with 19 wind turbines and 700 vessels. This plant configuration can sufficiently fulfill the city's annual water demand but at the expense of higher capital investment in terms of membrane vessels. It is also found that a tradeoff exists between the specific energy consumption and capital investment. Moreover, a tradeoff exists within the capital investment between the required number of turbines and vessels.