Introduction of a new Energy Recovery System—optimized for the combination with renewable energy Original Research Article

The ENERCON Desalination Department has developed a new energy recovery system for RO desalination plants, optimized for the combination with wind energy converters. The main problem for the combination of desalination processes and wind energy is the fluctuation of power supply generated through renewable energies. Conventional desalination plants (and the belonging energy recovery systems) work at a fixed operation point or in a very small range. ENERCON developed a system that can adjust the operation in a range of 12,5 - 100% energy availability - in a very energy efficient way! The energy recovery system consists of a low pressure pump (20bar) and three combined pistons (there is no need for a second/booster pump). This “piston type accumulator” is able to transfer the pressure up to 70 bar, needed for the desalination process. As a side effect we can also avoid the use of chemicals for the antiscaling and antifouling problem. We managed to avoid additives by a low recovery rate. In the combination with the very efficient energy recovery system we experienced an energy consumption within the RO unit between 2-2,8 kWh / m3 for sea water and between 0,8-1,3 for brackish water with our prototype plants in the Mediterranean sea. The ENERCON design enables a reduction of operation costs through low energy consumption and the avoidance of chemicals. Furthermore it is also a benefit for the environment. Our goal: A reliable, sustainable drinking water production of finest water quality!