Innovative concepts exist to help bulk carriers meet EEDI Phase 3 (Image: Wärtsilä/Oshima)
EEDI reductions for bulk carriers scheduled to be implemented under IMO’s EEDI requirements for newbuilding bulk carrier and tankers from 2025 under EEDI phase 3 “can mostly be met without major changes to the designs,” believes Johnny Kackur, business development manager at Wärtsilä Marine Solutions.
However, “some more major changes [will] apply for larger ships especially those over250.000dwt,” He predicted, but was confident that Wärtsilä “has technologies suitable for meeting requirements beyond EEDI phase 3.”
He was part of the project team behind Wärtsilä’s Ultramax 2030 bulk carrier design that was unveiled in October 2019 as a result of a joint project with Oshima Shipbuilding and DNV GL. The concept includes a sail, solar panels and batteries among its energy-saving features, and he told The Motorship that its study “demonstrates that we have existing and well demonstrated technologies available for further improvement.”
Alongside those technologies, another major change to conventional bulk carrier design could be a switch to LNG-fuelled propulsion using “new-generation propulsion machinery” along with shaft generators, which would make it possible to achieve “further reduction without reducing the service speed from today´s standard,” he said.
That propulsion machinery could be either low-speed two-stroke dual-fuel engines connected to fixed-pitch propellers, or medium-speed four-stroke engines; the Ultramax concept has been developed to suit either option, said Wärtsilä Marine Solutions’ chief expert on environmental expertise, Heikki Korpi. For both arrangements, Wärtsilä predicts an EEDI for the ship 46% less than Phase 0 levels, which exceeds the 30% reduction set for EEDI phase 3 from 2025.
Mr Korpi told The Motorship that the medium-speed multi-engine configuration based on Wärtsilä´s new-generation medium-speed engines with two-stage turbochargers and controllable-pitch propellers (CPPs) could be more efficient than a low-speed installation, but it would depend on the ship’s operating conditions: the benefits would come if there are opportunities to optimise the engines load range when less power is required.
In his comments, Mr Kackur said that using CPPs would ensure that “we will never over-load the main engine in any operating condition” and said that there is also a possibility to increase propeller efficiency with a CPP, because of its smaller propeller margin.
While these concepts will all help reduce EEDI, another Wärtsilä initiative that will reduce fuel consumption is not recognised by IMO’s formula Mr Korpi said. He would welcome changes to the calculation to recognise its benefits but “sometimes existing regulation is not able to acknowledge the benefits of new innovations,” he added.
The technology recovers volatile organic compounds (VOCs) from oil cargoes during loading and unloading and was first applied in 2018 on a shuttle tanker operated by Teekay, which jointly worked with Wärtsilä on its development. According to a Wärtsilä publication at the time, a conventional shuttle tanker releases large amounts of VOCs into the atmosphere during loading and transportation of crude oil. “Studies estimate that about 3,300 tonnes is released into the atmosphere, yearly, for every offshore loading [location].”
This is recovered and stored as gas and liquid, with the gas being used to fuel a steam turbine, but the liquid VOCs can be added to LNG and used in dual-fuel engines. This improves a ship’s overall efficiency, but it is not reflected in its EEDI calculation, Mr Korpi said. When new technologies are developed, “it’s a challenge for the regulators to create ways to take them into account.”
The next steps of EEDI are under discussion in an IMO correspondence group but any changes it introduces would be too late to have an impact in the near future, he said. As for VOC emissions, these form part of IMO’s greenhouse gas strategy and as soon as the main short term GHG measures have been agreed, “feasible ways of acknowledging this, together with other new energy saving technologies in the EEDI calculation, should be taken under discussion,” he added.