Robust optimal self-scheduling of potable water and power producers under uncertain electricity prices

Abstract

Recently, seawater desalination and power generation units are optimally co-scheduled because of interconnection between electricity and water networks. A typical water-energy hub grid consists of the conventional thermal power plants and the combined water and power (CWP) generating units. In the CWP plants, the waste heat of the flue gases exhausted from the power generation process is utilized for water treatment. If the water and power generation company aims to maximize its daily profit, the electricity price uncertainty will affect the optimum operating point of the generating units. In other words, the fluctuations of the energy prices cause the power generation patterns of thermal and CWP units to change. Hence, this paper implements a robust optimization strategy on water-power nexus model to handle the uncertainty of the electricity price with no need for its probability distribution and membership functions. The lower and upper bounds and the forecasted prices are used for solving the robust mixed-integer non-linear program and making the risk-averse decisions against the uncertainty. It is indicated that the proposed approach is suitable for the price taker water-power cogeneration companies, which seek the optimal schedule of their thermal and CWP units for a certain operating period.