Optimal Participation of Water Desalination Plants in Electricity Demand Response and Regulation Markets

As freshwater resources progressively decline, desalination capacities around the world are projected to increase. However, high electricity consumption costs hinder the broader development of desalination plants. A promising solution to offset a portion of these costs is to enable water distribution system operators (W-DSOs) to offer the flexibility of their water desalination plants in electricity markets. This article proposes a model to integrate the available flexibility of water desalination plants in W-DSOs operation and optimize their participation in electricity demand response (DR) and frequency regulation markets. The proposed model co-optimizes the operation of desalination plants with variable speed pumps and water storage tanks in order to optimally allocate the available WDS flexibility between the day-ahead energy and frequency regulation markets. The proposed model takes into account the hydraulic operating constraints of the WDS, thus ensuring the delivery of DR and regulation services in the markets while supplying the water demand at the desired pressure. In addition, the proposed model considers the unavailability of freshwater resources when providing flexibility services to the grid, thus enabling W-DSOs to balance their profits against water shortages. The numerical studies, conducted on a test 15-node water network, show that the proposed model effectively utilizes the operational flexibility of desalination plants to offer DR and regulation services in the markets, considering the hydraulic constraints of the WDS, freshwater availability conditions, and desalination plants' freshwater recovery rates.