The deadline for bids is 31 March 2008.
Bidders can submit an offer for either the power plant package or the desalination package or both.
Dewa may invite the successful bidders for the individual packages to form a consortium led by the winner of the power package.
The plant will have a capacity of 1,500 MW and 120 million gallons a day of desalinated water.
The power plant will use gas turbines and the desalination plant will remove the salt from the water using a process called multi-stage flash.