By Juan Pinto, Senior Director, Global Water Sales OEM, Energy Recovery, and Angel Abajas, Senior Sales Manager, Energy Recovery
Freshwater is one thing a vessel can’t run out of, and far enough from port, the only practical way to get it is to make it onboard from seawater. Seawater reverse osmosis (SWRO) is well proven, but the conditions around it change everything at sea: space is fixed, power is typically generated onboard from fuel, and service support is far away. Energy already accounts for roughly 30% to 50% of the cost of producing water in a land-based SWRO plant, and systems without effective energy recovery can exceed 7.5 kWh/m³. At sea, every kilowatt-hour avoided means less fuel burned and more electrical capacity for the rest of the vessel.
This article makes the case for treating the energy recovery device (ERD) as a core design choice rather than a component added later, across aquaculture wellboats, cruise ships, livestock carriers, and offshore operations.
The PX® Pressure Exchanger® transfers pressure directly from brine to feedwater at up to 99% efficiency, cutting overall SWRO energy consumption by up to about 60%, with a compact footprint, one moving part, and no scheduled maintenance.
One recent retrofit shows the payoff: the livestock carrier Saphira more than doubled production to 450 m³/day at 2.51 kWh/m³, saving an estimated 518,000 kWh and $51,800 a year.
