Energy-saving propeller cap

Finland-headquartered marine propulsion giant Wärtsilä, says its EnergoProFin is ‘a state-of-the-art energy saving solution that increases propeller efficiency and creates fuel savings of up to five percent’. The solution is now available for both controllable pitch propellers (CPP) as well as fixed pitch propellers (FPP), yielding the same results in both propeller options.

Offering the solution for technologically more challenging CPPs was previously considered impossible in the industry, but is now made possible due to development work by the Wärtsilä hydrodynamics team.

The Wärtsilä EnergoProFin is a specially designed propeller cap with hydrofoil section fins on the downstream side of the propeller. It is an innovative energy saving device that can significantly reduce a vessel's fuel consumption as well as its emission levels. Such technical innovations play a major role for ship operators who are tackling rising operating costs, as it offers an opportunity to enhance the efficiency of existing assets. By improving their energy efficiency, ship operators can increase their profitability in an environmentally sound way.

Propeller caps with fins have existed for three decades, but their application has so far been primarily on FPPs. The view of the industry has been that applying an energy saving device such as Wärtsilä EnergoProFin to the technologically more challenging CPP would not be possible. Wärtsilä took on the development task and succeeded in creating a product that offers vessels equipped with a CPP an opportunity to reduce their energy consumption. Wärtsilä's development work was a spin-off of an EU-funded collaborative project between Wärtsilä and nine other companies.

The device rotates with the propeller and is optimised for propulsion upgrades of existing vessels and as such can be easily mounted without the need for complex structural changes. The device is designed to minimise the losses in the vortex leaving the propeller by transforming rotational energy into effective thrust, resulting in an efficiency increase that Wärtsilä claims brings up to five percent fuel savings. The payback time for the investment is, even with the current low fuel prices, generally less than two years and can be as short as less than a year.

"Customers in today's uncertain economic situation need solutions that are reliable, cost-effective and easy to invest in. Energy efficiency solutions in general are a sound investment, as their impact on both operating costs and environmental compliance is a lasting one," said Tamara de Gruyter, Vice President, Propulsion System Services, Wärtsilä Services. "We want to help ship operators optimise their existing assets, and that is exactly what Wärtsilä EnergoProFin does, now for controlled pitch propellers as well."