The vessels have been equipped with EGC (Exhaust Gas Cleaning) for HFO operations, which ensures a very cost-efficient operation. When HFO is used together with EGC, the result is an environmental-friendly solution. The waste from the cleaned exhaust is delivered ashore.
The question is not which fuel to use, but how the fuel is used. Technically, high quality HFO is an excellent fuel, which again ensures low maintenance cost for the machinery. HFO has also the highest energy density of all available fuels, which again maximizes the cruising range and/or minimizes the overall CO2 footprint from the cargo transported.
Up to now the exhaust gas cleaning has only been economical in the SECA area (sulfur emission control areas), but from 2020 with the new IMO emission regulation (0.5 percent sulfur), all vessels need either exhaust gas cleaning (scrubber) or they have to operate on MGO or a similar low-sulfur distillate. In the “well to wake” perspective, HFO operation yields approximately 10-15 percent lower CO2 emissions than operation on MGO.
The new vessels have a hybrid exhaust gas cleaning system combined with Solvang low pressure EGR (Exhaust Gas Recirculation) system. This system has been developed on-board our own vessel Clipper Harald, whereby the NOx emission was reduced by almost 80 percent upon using low-pressure EGR. When combining exhaust gas cleaning and EGR we get a very cost-efficient all in one-solution. Compared to MGO operations, savings are estimated to 5000-6000 USD per day.
The auxiliary engines are equipped with a catalyst for NOx reduction.
The main engine is a two-stroke HFO fuelled diesel engine operating at 104 RPM with direct driven propeller. This gives an overall efficiency (engine to propeller) close to 50 percent, which is higher than all other engine alternatives (including hybrid electric solutions etc).
The vessel is optimized for both short and long-haul trade and the fuel capacity together with exhaust gas cleaning allows the vessel to sail more than 50 days without bunkering. Compared to our previous vessels, this is a 50 percent increase in cruising range.
The vessels are furthermore fitted with a high-lift rudder combined with an integrated Swirl Generator to increase the propulsion efficiency. The high-lift rudder also ensures maximum low-speed maneuverability, which is an important safety feature. As a part of our newbuilding program the vessels undergo extensive model tests to establish optimum trim conditions on different loads. The Solvang effort to improve fuel efficiency has improved the EEDI rating by 7-8 percent.
The cargo plant is based on our more than 40 years of ethane/ethylene transport experience. Compared to previous generations the cargo plant achieves about 15-20 percent shorter cool-down time.