The need for greater energy efficiency has assumed major importance for container ship owners. Reducing fuel consumption and improving the operating efficiency of onboard power systems has become vital from an economic point of view to cut fuel costs, and to meet the tightening environmental regulation of emissions.
This imperative is generating a raft of new products and services developed by class societies and other suppliers, offering various software tools for monitoring and managing energy efficiency and emissions. Container ships are a particular target due to the nature of liner operations and expected long-term growth, the relevance of speed and related emissions, and the new generation of super post-Panamax vessels that are seeking to achieve greater efficiency.
In September, class society Germanischer Lloyd (GL) used the SMM international trade fair in Hamburg to launch GL Emission Manager, which enables the collection, tracking and calculation of ship emissions in detail. The system has been developed in collaboration with German liner operator Hamburg Süd. It can be used for a variety of purposes including onboard energy management and the provision of information to regulators and shipper clients, who increasingly are demanding evidence from operators about the environmental footprint of their cargoes.
GL Emission Manager is a software tool that is designed to provide a means of recording data in a systematic way so that it can be used reliably as the basis for reports and analysis. This includes position and other operational reports, cargo information, fuel consumption, air emissions, ballast water and related chemicals, and other environmental factors such as garbage, sludge and grey water.
At the launch, GL head of maritime software, Torsten Büssow, said: “The GL Emission Manager works with data that is already being entered manually today. But because currently this is not being collected in one tool, making additional evaluations and conclusions based on the data is not possible.”
Information is collected by emission recorder software and analysed by a so-called green server. The emission recorder software is installed on a shipboard computer and records information in a standardised format. This information is transferred to the shore-based green server which logs and stores the data, enabling detailed analysis and the compilation of reports for internal management or for external use, including regulatory, class or environmental databases such as the Clean Shipping Index.
"GL Emission Manager's comprehensive reporting capability allows owners and operators to set targets and measure target achievement - two basic requirements for the SEEMP [ship energy efficiency management plan], for example," said Dr Büssow. "The system offers shipowners the opportunity to set up comprehensive emission reporting for the entire fleet using the data they already have; to benefit from comprehensive fleet analysis capabilities across all operational and voyage data; and to improve data quality and integrity to the highest certifiable standards."
ABB’s energy management system for marine applications (EMMA) sets a mathematical baseline to measure the use of fuel on a scientific basis, related to all aspects of ships’ operations. German owner Rickmers is installing it on a series of five multipurpose vessels and container ships.
Jens Lassen, global head of Rickmers Maritime, says: “To date, ship managers, owners and charterers have failed to come together to devise ways of making savings. Rickmers recognised and addressed this particular failing and is about to sign its first contract for fuel saving on a long-term chartered ship. The main thing is to be able to set the baseline, because you cannot measure unless you know where you are measuring from.”
The EMMA Advisory Suite comprises three software modules: Onboard Tracker, Fleet Control and Advanced Optimizer. The system divides the vessel into energy areas and delivers a key performance indicator (KPI) for each area. By collecting and processing data in real-time, EMMA compares energy consumption with targets and continuously shows the performance status of each KPI on a visual indicator.
Rickmers retrofitted ABB’s dynamic trim software on its 13,100 teu Aqua Rickmers, achieving a six per cent fuel cost saving by adopting optimal trim. “Fuel represents 88 per cent of costs while our shipmanagement costs are only 12 per cent. We can make a difference by addressing the 88 per cent element,” says Mr Lassen. “Fuel savings for existing ships will probably take up to three years to realise, in three stages.”
UK company Martek Marine’s MariNOx onboard emissions monitoring system, covering NOx, SOx, CO2 and engine efficiency, has achieved type approval from Lloyd’s Register and IMO compliance. It allows ship operators to monitor exhaust gases enabling the optimisation of engine performance to generate fuel savings of up to four per cent, according to the company. The DataLINK emissions software allows vessels’ air emissions to be viewed in real time. Martek says that the system gives ship operators the freedom to adjust the settings of their engines to suit their own operating preferences, whether in low NOx or fuel efficiency mode, or a combination of both, based on the geographical area of trading.
Since its introduction in 2010, MariNOx has been fitted on more than 100 vessels, including container ships, with leading charter owner Peter Döhle Schiffahrts among its users.
Paul Luen, Martek’s managing director, says: “With growing pressure from customers across the supply chain, the maritime transport element of box movements is under increasing scrutiny. More consumers want to know how their purchase got to the shop. Supply chain managers want to know the carbon cost of moving a container around the world, and whether the choice of carrier makes a difference to the environmental impact of the journey. Consequently we are seeing more shipping companies including emissions data alongside their financial results.”
At Peter Döhle, fleet manager Kurt Brieger commented: “The equipment was installed in-passage by the Martek service team with assistance from the ship’s engineers. The installation did not affect the vessel’s operation. Various trials were carried out on the main engine, a Wärtsilä 10RTA96-C, to measure NOx, CO2 and fuel oil consumption. The trials concluded that fuel savings in the range 0.6–2.1 per cent were delivered.”
Class society ABS has launched its new Energy & Environmental Manager module, part of the NS5 Enterprise asset management software suite, as the latest addition to its portfolio of services to help owners and operators meet environmental and operational demands and improve vessels’ energy efficiency.
ABS says that a key objective of Energy & Environmental Manager is to help owners and operators achieve more environmentally-sound voyage management by tracking and recording key voyage-related events, including fuel and lube oil consumption, fuel oil switching, cargo information and ballast activities. The module is enhanced by a trim optimisation tool, which adds trim and draught optimisation for improved fuel savings. It also performs multiple analyses to obtain an optimised ballast configuration to achieve minimum hull resistance.
ClassNK in Japan has developed a software package, Napa Green, for optimising voyage planning for existing vessels in dynamic operational situations. Executive vice-president Yasushi Nakamura says that the functions it covers include trim optimisation, voyage planning, weather routing, propulsion resistance, and speed optimisation. “Its unique selling point is dynamic eco-efficiency, with automatic re-tuning during vessel operations rather than based on pre-settings.”
ClassNK’s aim is to provide a solution to reduce fuel costs and emissions, and help ship owners and operators comply with SEEMP regulation. According to the class society, the software uses a physically accurate dynamic performance model which is fine-tuned with advanced analysis of measured operational data. Real-time monitoring and post-voyage analysis service provide decision support, and improved operational efficiency.
Napa Green has been developed in collaboration with Finnish software company Napa and Imabari Shipyard to apply the system and improve it. The software, which is still under development, is based on the Microsoft operating system. The first ship fitted with the system will be in service next year.
Mr Nakamura said that ClassNK is aiming to increase its market share of classification of container ships. It currently ranks second, but still a long way behind the clear leader in this sector, GL.
German electric-drive specialist Siemens is installing its waste heat recovery (WHR) system on board the 20 Maersk Line Triple E 18,000 teu ships being built at Daewoo Shipbuilding & Marine Engineering in South Korea. Andreas Schwann, head of marine and shipbuilding at Siemens, says that WHR systems save 12 per cent energy consumption and offer a 10 per cent reduction in emissions.
Siemens will install shaft generator motors and power generating systems based on the utilisation of waste heat in 20 Maersk container ships. The ships have a twin propulsion system with two slow speed engines driving separate propellers. A 3MW shaft generator/motor is mounted on each shaft. Together they supply up to 6MW of additional power. The Siemens shaft generator motors are coupled to the WHR system.
The vessels will also feature the new Siemens EcoMain energy saving product. This integrates data from the different ship’s systems, acting as a decision support system but not directly controlling the ship’s systems. WHR optimisation is one of the EcoMain system applications. EcoMain is still under development but a pilot installation will be placed on the first Triple E vessel with a view to installation across the rest of the 20 Triple E ships that are on order, and other Maersk container ships.
Kay Tigges, Siemens’ senior engineer, marine solutions technology, says that Maersk already has many vessels with WHR systems, so there is a lot of potential. “The system will be tested and verified on the first Maersk Triple E ship and installed on the second ship. If successful it will be installed on the whole series and then possibly across the wider Maersk container ship fleet.” Another operator with WHR systems on board and considering EcoMain is United Arab Shipping Co (UASC).
Mr Tigges says: “Currently about half of the primary energy is lost as waste heat. That is why it makes sense to use a heat recovery system to convert this waste heat into electrical energy.” The hot exhaust from the prime mover is used to generate steam, which drives a generator by a steam turbine, adding several additional megawatts in electrical energy to the power supply on board. This power can be used to power electrical auxiliary drives mounted directly on the drive shaft. Doing this increases the overall efficiency of the ship's engine by about 55 per cent in terms of shaft power. Energy costs drop by about 12.3 per cent for a ship operating with power take in/off and heat recovery, compared with a conventional ship without these enhancements.
On the 15,500 teu Emma Maersk, which is equipped with a WHR system, fuel consumption is 0.171 kg/kWh at full power, equivalent to about 2.7 l HFO per 14 tons of containers moving 100km. The WHR system increases the engine's total output by 9,860 kWh, or 12 per cent, while reducing the specific consumption to 0.158 kg/kWh.
MAN updates engine programme
MAN Diesel & Turbo has updated its two-stroke marine engine programme, including significant improvements to the G-type portfolio that is used in container vessels. The G-type engines can facilitate the use of larger, more efficient propellers with lower speeds, using an ultra-long stroke that reduces engine speed. This enables the design of ships with increased propulsion efficiency and lower Energy Efficiency Design Index measurements. The G40 and G45 have recently been added to this series.
MAN Diesel & Turbo has recently acquired Kappel propeller designs, adding a fixed-pitch option to its portfolio. The company says that this will help to accommodate the use of G-type engines in cases where minimal changes to existing ship designs are not feasible, but more complex re-designs are needed in order to make greater efficiency gains.
Wärtsilä secures Generation X order
An order has been placed for six of Wärtsilä’s new X72 main engines for installation on board four newbuild container ships for Pacific International Lines, under construction at Dalian Shipbuilding Industry Co in China. The first engines are due to be delivered in early 2014.
The X72 is one of the engine supplier’s recently-introduced Generation X engines, designed to offer compliance with environmental legislation and improved fuel consumption in line with Energy Efficiency Design Index requirements (see CST November 2012). According to Martin Wernli, vice president of Wärtsilä ship power, two-stroke, the container vessels can achieve savings of four tons per day of fuel compared with similar recently-delivered vessels.
Becker Twisted Fin for box ships
Becker Marine Systems’ Mewis Duct, which is placed in front of the propeller to improve water flow and thereby save energy, has become a widely known option for fuel saving. Becker estimates that the average fuel saving is six per cent, based on tests with and without the duct, and up to eight per cent when combined with a Becker rudder.
The benefits of the standard version are, however, mainly confined to ships with a full hullform, such as tankers and bulk carriers. For vessels with finer hull forms, such as container ships, at speeds of about 18 knots or more the increasing water flow resistance of the Mewis Duct equalises the saving. Because of this, Becker has developed an enhanced version, the Becker Twisted Fin.
According to Becker’s managing director, Dirk Lehmann, the Becker Twisted Fin has no moveable parts and is installed in front of the propeller, generating a pre-swirl. This provides fast ships with energy savings. The main difference from the Mewis Duct is that the nozzle ring is smaller and it has a slimmer profit, with the fins on the inside of the nozzle ring extending outwards. Specially designed end caps for the fins prevent the formation of a swirl with cavitation at the end of the fins.
Becker says that computational fluid dynamics tests show an average of three per cent fuel saving for container ships. The first model tests are being conducted towards the end of 2012. Mr Lehmann says that several large container companies and shipbuilders have expressed interest.CST
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