By Juan Pinto, Senior Director, Global Water Sales OEM, Energy Recovery, and Stephane Kessaci, Business Development Manager, Europe, Energy Recovery
Europe’s record-breaking summer heat did more than strain power grids. It exposed how tightly water and energy are now linked. As drought deepened across the continent, utilities faced a preview of a challenge that will only intensify: desalination and wastewater reuse both demand significant electricity, right as that electricity becomes less reliable and more expensive. Energy efficiency has shifted from a cost-saving nicety to a core design decision for water infrastructure.
The reverse osmosis stage, often more than 60% of a plant’s total power draw, is the area engineers can most influence, and energy recovery devices are already reducing that burden across very different settings, from a direct potable reuse plant in Belgium to a zero liquid discharge facility in China. As regulations like the recast Urban Wastewater Treatment Directive push utilities toward more energy-intensive treatment, and as tenders increasingly weigh lifecycle energy performance, efficiency is no longer optional. It is quiet risk management: fewer surprises, steadier costs, and water that keeps flowing when the grid is stretched thin.
Energy recovery devices work by capturing the pressure in a system’s reject stream, water that would otherwise be discharged as waste, and transferring it back to the incoming feed, so pumps and the grid behind them do far less work. In Hofstade, Belgium, adding this technology to a direct potable reuse plant cut electricity use in that stage by about 23%. In a zero liquid discharge facility in Hubei, China, operating at much higher pressure, it reduced electricity consumption in the highest-pressure stages by roughly 51%. The results look different depending on the plant, but the underlying physics, and the savings, hold true across both.
