Expansion planning of generation technologies in electric energy systems under water use constraints with renewable resources

Thermal power generation needs great volumes of water for cooling purposes. A multi-period Low Water Generation Expansion Planning (LW-GEP) model is proposed to plan the future generation mix including type, capacity, time of installation, and proper cooling system of generation technologies to supply the future electric peak loads under the water resource limitations. Different types of generation technologies with conventional and modern cooling systems are considered as expansion candidates in the proposed LW-GEP model. The access of candidate and existing power plants to the water resources are considered. Renewable resources as water smart solutions are integrated in the proposed energy planning model. According to the obtained results, the regional water use constraints impact the generation mix significantly in favor of the dry-cooled and open cycle units. Using the proposed LW-GEP model, the total saving in water consumption for the simulated large scale power system, in regions with water stress and scarcity conditions, reaches to 3.7 x 10(9) m(3), that is approximately equal to the water consumption of a metropolis such as Tehran in three years. Also, it is shown that the integration of renewable resources as water smart solutions results in reduction of expansion planning cost and more water saving.