DNV GL: A Team Effort

The first design, the Oshima Ultramax 2030, boasts a 50% reduction in energy efficiency design index (EEDI). Developed together with technology group Wartsila, it was introduced at Nor-Shipping 2019 in Oslo (Norway).

With an EEDI close to 50% lower than comparable vessels, the new Ultramax design is one of the most efficient bulk carrier designs to date.

With 2008 as a baseline, the IMO strategy aims to reduce total GHG emissions from shipping by at least 50% by 2050, and to reduce the average carbon intensity, or CO₂ per tonne-mile, by at least 40% by 2030, while aiming for a 70% reduction by 2050. Beyond 2050, IMO’s ultimate vision is to phase out GHG emissions as soon as possible within this century.

“To help the industry meet the ambitious GHG reduction targets set by the IMO, the industry needs to come together to advance ship design. This design halves the EEDI of comparable vessels and sets a new standard for low emission bulk carriers,” said Trond Hodne, Director of Sales & Marketing at DNV GL. The strategic cooperation between Oshima and DNV GL will continue through 2030, working towards the IMO zero emissions scenario with annual joint industry projects (JIPs), where other partners will be invited to join.

The new Oshima Ultramax 2030 design maximises operational performance while minimising emissions by utilising LNG as fuel, an optimised hull shape, a sail to generate extra propulsion, as well as solar panels and a battery to cover the hotel load during waiting times and port operations.

Meeting tomorrow’s requirements today

The Ultramax 2030 design maximises operational performance while minimising emissions by utilising LNG as fuel, with an optimised hull shape and a hard sail to generate extra propulsion. In addition, the design uses solar panels and batteries to cover the hotel load during waiting and port operations. The array of options introduced in the new design includes a shaft generator with a battery pack and two different main engine alternatives. The first engine option is a high pressure, two-stroke dual fuel engine, while the second option includes a four-stroke dual fuel engine.

According to input from major shipowners, fleet profile research and AIS analysis of trade, ports, bunkering and cargoes, 40% of major ultramax ports already have access to LNG terminals, with more in the planning and building stages. Worldwide operation is the ultimate requirement for deepsea ships using LNG propulsion, and current availability allows for bunkering of a 2000 m³ LNG tank with the Oshima Ultramax 2030 design, giving a range of 13 600 nautical miles – enough to cover the main global trading pattern of a round trip of Singapore to South Africa.

A typical ultramax spends only just over 50% of its time in sailing mode, while the remainder is spent either waiting or loading/unloading. Availability of shore power is currently estimated at only 2% of major ultramax ports. With this in mind, particular attention was paid to reducing emissions while waiting and in port, in order to shrink the overall environmental footprint, not just while sailing.

The power of the sun

Solar panels on the ultramax 2030 design are installed on top of the hatch covers, and will generate up to 88 kW/hr during sunlight hours, with the remaining 42 kWh supplied by battery. This covers the expected consumption of the highly optimised hotel load of only 130 kWe in ‘eco mode’ during waiting times.

Total solar panel area is about 1500 m², including all hatch cover surfaces. The 88 kW/d output will provide annual savings of an estimated US$67 000, including fuel and maintenance of gensets. The payback period for solar panels and batteries is expected to be around 10 years.

At night, battery power can be used for 3 hours before the battery is discharged. Whenever charging is required, diesel fuel gensets will run at optimum engine load to charge the batteries and cover the hotel load. Approximately 1 hour is required to fully charge the battery.

Sailing to savings

The glass fibre reinforced plastic (GRP) hard sail generates additional thrust to supplement propulsion power. The sail automatically rotates to the optimal angle of attack to maximise thrust in response to changing wind conditions. The hard sail system is being developed jointly by Oshima and Mitsui O.S.K. Lines.

The sail height is 60 m, and the design satisfies Safety of Life at Sea (SOLAS) visibility requirements. The sail will be folded in unfavourable wind conditions and during loading and unloading. Oshima carried out computational fluid dynamics (CFD) analysis together with Tokyo University, using selected weather data for one year in the North Pacific. Expected fuel savings from sail use is up to 10%. Yearly fuel savings based on the current operational profile is estimated at US$130 000.

Signing the long-term strategic co-operation agreement between DNV GL and Oshima: Trond Hodne, Director of Sales & Marketing at DNV GL (left), and Eiichi Hiraga, President of Oshima Shipbuilding (right).

Energy Efficiency Design Index

The Energy Efficiency Design Index (EEDI) is a design index indicating the energy efficiency of a ship in terms of CO₂ per tonne-mile at a specific draft and speed. The EEDI for new ships aims at promoting the use of more energy efficient and less polluting equipment and engines. EEDI requirements were adopted as amendments to MARPOL Annex VIÊinÊ2011 and entered into force in 2013.

The minimum energy efficiency level in the EEDI is to be tightened incrementally every 5 years, with the aim of stimulating continued innovation and technical development of all the components influencing the fuel efficiency of a ship from its design phase. The choice of technologies for specific ship designs is left up to the industry. As long as the required energy efficiency level is attained, ship designers and builders are free to use the most cost-efficient solutions for the ship to comply with the regulations.

The EEDI covers the largest and most energy-intensive segments of the world merchant fleet. This means that ships responsible for approximately 85% of CO₂ emissions from international shipping are incorporated under the international regulatory regime, according to the IMO.

Making a greener future together

An additional aim of the Ultramax 2030 project has been to create a new standard that maximises the return on investment (ROI) for the owner. One key objective was to minimise greenhouse gas emissions through the application of currently available technologies.

“Our smart marine initiative emphasises collaboration between the various stakeholders, and this project is a prime example of how effective such collaboration can be,” said Stein Thorsager, Director, Merchant and Gas Carrier, Wartsila Marine.

“The design is based on actual operating profile data from ultramax bulk carriers, and incorporates an LNG-fuelled Wartsila 31DF dual-fuel main engine as one of the two engine options, connected to a power take out (PTO) shaft generator and controllable pitch propeller (CPP). The result outperforms all existing designs in terms of efficiency and sustainability,” he stated.

Eiichi Hiraga, President at Oshima Shipbuilding, noted: “Greater efficiency and better environmental performance have been made possible with the collaboration and initiative of Wartsila and DNV GL.

“Oshima alone could not have come up with this new innovative design, which includes optimised propulsion, energy storage and solar panels. It represents a future-proof solution that will enable bulk carrier owners to comply with legislation while also lowering operating costs.”

Meeting such ambitious targets will call for significant technological development, a challenge both Oshima and DNV GL are willing to accept. “Our companies have significant and largely complementary know-how in the relevant fields of expertise necessary for such an ambitious development,” Hodne concluded.

Read the article online at: https://www.drybulkmagazine.com/special-reports/11122019/dnv-gl-a-team-effort/