Air lubrication technology reduces shipping drag by injecting compressed air beneath vessel hulls, lowering fuel consumption and emissions. Commercial systems already operate on cargo ships globally. The challenge lies in energy costs.
Everllence and Silverstream Technologies developed an Engine Supported Air Lubrication system that sources compressed air from a ship's main engine exhaust. This approach differs from conventional air lubrication, which requires dedicated compressors consuming substantial electrical power.
The concept addresses a fundamental constraint. Traditional air lubrication systems reduce fuel use by 5 to 15 percent but demand significant onboard energy to generate pressurized air. That energy overhead can negate environmental gains unless ships employ renewable power sources.
Engine-supported systems capture waste heat and pressure from diesel engines, theoretically eliminating the parasitic energy load. Ships already burn fuel to turn propellers; extracting air from exhaust streams requires minimal additional power input.
Maritime shipping accounts for roughly 3 percent of global carbon dioxide emissions, roughly 940 million metric tons annually. Even modest fuel reductions across commercial fleets translate to measurable emissions decreases. Air lubrication offers a retrofit solution for existing vessels without requiring engine replacement.
The trade-off surfaces immediately. Compressing air diverts energy from the propulsion system. Operators must calculate whether drag reduction outweighs the energy penalty. Silverstream reports their systems achieve net fuel savings of 4 to 8 percent on tested vessels, but results vary based on ship design, operational profile, and sea conditions.
Everllence's engine-supported approach potentially improves that equation by reducing the power required to generate sufficient air pressure. No independent data on this specific system's performance exists yet, though patents and technical papers outline the engineering principles.
The broader shipping decarbonization picture includes scrubber technology, alternative fuels like ammonia and methanol