Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:


Fuel Prices and Environmental Charges Slow down the Speed of Ships

Shipping Companies Look to new Propulsion Concepts and the Recovery of Energy from Ship Exhaust Gases

Challenged by high energy costs and rising environmental requirements, more and more shipping companies are looking to new propulsion concepts as a solution to their problems. They are now focusing their strategic decisions on saving energy, reducing emissions and optimizing engine size instead of speed.

Diagram showing how the energy from a ship\'s exhaust gases is used

“Shipping companies are rethinking their position”, explained Ernst-Christoph Krackhardt, who works for Siemens Marine Solutions and is responsible for merchant shipping. “They are deciding in favor of less powerful but more efficient and more cost-effective engines for their ships. To this end, all potential sources of energy such as exhaust gases are being utilized for efficiency increase.”

High fuel prices, investment security, carbon certificate trading and port registration are the issues that are confronting shipping companies and dockyards today and are influencing the construction of new ships. On the one hand, operating costs can be lowered substantially if the speed of a ship is reduced. For example, if a container ship drops its speed from 25 knots to 20 knots, fuel costs fall by up to 40 percent. The engine power needed to propel the ship also falls correspondingly. In future, this will allow for lower-powered engines. “On the other hand”, said Krackhardt, “the solutions developed by Siemens for recovering energy from ships' exhaust gases - waste heat recovery systems - result in a considerable improvement in the energy balance, especially when they are combined with booster drives.” These solutions can be incorporated at the design stage for new ships and can also be retrofitted in existing ships at an acceptable conversion cost. In the case of 8 ships belonging to a Danish shipping company, fuel consumption was reduced by well over ten per cent per ship solely through the use of the ship's exhaust gases to produce electricity. “From a ship's exhaust gases, we generate up to 9 MW of electricity which can be fed into the on-board power system and/or used for the booster drive, an electric motor mounted on the propulsion shaft in order to increase propulsion power”, said Krackhardt.

The way a waste heat recovery system works is to use the energy contained in the hot gases from a ship's diesel engines to produce steam in downstream waste-heat boilers and thus drive turbo-generators that generate energy for the on-board power supply system rather than allow the energy in the exhaust gases to escape into the atmosphere through the ship's funnel. Additional electrical power can also be generated/emitted with the generator/motor which is mounted directly on the propeller shaft. If the output of the main propulsion unit is not being fully utilized, this shaft generator can make electrical energy available to the on-board power supply system, thus placing a greater burden on the main engine. This results in more exhaust-gas energy being generated less expensively, which makes it possible to significantly reduce the operating times of the on-board diesel generator. Moreover, the shaft generator can be used as an electric motor to increase the overall propulsion power of the ship, thus producing a higher speed when necessary. On top of all this, the shaft generator can be used in motoring mode as the sole means of propulsion during maneuvers in harbors or at slow speeds. During these maneuvers, the main propulsion unit (usually a large diesel engine) can even be switched off and uncoupled from the shaft. All the functions are controlled by means of an energy management system which automatically adapts the available energy and operation of the shaft generator/motor to current requirements, while making optimum use of this energy. The waste heat recovery system enables flexible generation and use of electrical energy. The energy management system optimizes the efficiency of the main engine and reduces the operating times of the generator sets and thus their operating and maintenance costs. Dockyards can integrate the waste heat recovery system in order to design a main engine with a lower rating and thus use the engine room more flexibly as the shaft generator is installed in the existing propulsion shaft tunnel and does not therefore require any additional installation space.

Given the current high prices for fuel, Krackhardt calculates that retrofitting a waste heat recovery solution is an investment that pays for itself within a mere two and a half years. “If a ship has a useful life of 25 to 30 years, this is definitely worthwhile – for both ship-owners and the environment. It also creates the option of being able to enhance the carbon trading scenario to the benefit of everyone involved.”

Further information on solutions for merchant shipping and the navy at:
The Siemens Industry Sector (Erlangen, Germany) is the world's leading supplier of production, transportation and building systems. Integrated hardware and software technologies combined with comprehensive industry-specific solutions enable Siemens to enhance the productivity and efficiency of its customers in industry and infrastructure. The Sector comprises six Divisions: Building Technologies, Industry Automation, Industry Solutions, Mobility, Drive Technologies and Osram. In fiscal 2007 (ended September 30), Siemens Industry generated sales of approximately EUR40 billion (pro forma, unconsolidated) with around 209,000 employees worldwide. With the business activities of Siemens VAI Metal Technologies, (Linz, Austria), Siemens Water Technologies (Warrendale, Pa., U.S.A.), and Industry Technologies, (Erlangen, Germany), the Siemens Industry Solutions Division (Erlangen, Germany) is one of the world's leading solution and service providers for industrial and infrastructure facilities. Using its own products, systems and process technologies, Industry Solutions develops and builds plants for end customers, commissions them and provides support during their entire life cycle.

Wieland Simon | Siemens Industry Solutions
Further information:

More articles from Power and Electrical Engineering:

nachricht Neutrons pave the way to accelerated production of lithium-ion cells
20.03.2018 | Technische Universität München

nachricht Monocrystalline silicon thin film for cost-cutting solar cells with 10-times faster growth rate fabricated
16.03.2018 | Tokyo Institute of Technology

All articles from Power and Electrical Engineering >>>

The most recent press releases about innovation >>>

Die letzten 5 Focus-News des innovations-reports im Überblick:

Im Focus: Mars' oceans formed early, possibly aided by massive volcanic eruptions

Oceans formed before Tharsis and evolved together, shaping climate history of Mars

A new scenario seeking to explain how Mars' putative oceans came and went over the last 4 billion years implies that the oceans formed several hundred million...

Im Focus: Tiny implants for cells are functional in vivo

For the first time, an interdisciplinary team from the University of Basel has succeeded in integrating artificial organelles into the cells of live zebrafish embryos. This innovative approach using artificial organelles as cellular implants offers new potential in treating a range of diseases, as the authors report in an article published in Nature Communications.

In the cells of higher organisms, organelles such as the nucleus or mitochondria perform a range of complex functions necessary for life. In the networks of...

Im Focus: Locomotion control with photopigments

Researchers from Göttingen University discover additional function of opsins

Animal photoreceptors capture light with photopigments. Researchers from the University of Göttingen have now discovered that these photopigments fulfill an...

Im Focus: Surveying the Arctic: Tracking down carbon particles

Researchers embark on aerial campaign over Northeast Greenland

On 15 March, the AWI research aeroplane Polar 5 will depart for Greenland. Concentrating on the furthest northeast region of the island, an international team...

Im Focus: Unique Insights into the Antarctic Ice Shelf System

Data collected on ocean-ice interactions in the little-researched regions of the far south

The world’s second-largest ice shelf was the destination for a Polarstern expedition that ended in Punta Arenas, Chile on 14th March 2018. Oceanographers from...

All Focus news of the innovation-report >>>



Industry & Economy
Event News

Virtual reality conference comes to Reutlingen

19.03.2018 | Event News

Ultrafast Wireless and Chip Design at the DATE Conference in Dresden

16.03.2018 | Event News

International Tinnitus Conference of the Tinnitus Research Initiative in Regensburg

13.03.2018 | Event News

Latest News

Physicists made crystal lattice from polaritons

20.03.2018 | Physics and Astronomy

Mars' oceans formed early, possibly aided by massive volcanic eruptions

20.03.2018 | Physics and Astronomy

Thawing permafrost produces more methane than expected

20.03.2018 | Earth Sciences

Science & Research
Overview of more VideoLinks >>>