A report commissioned by Siemens AG in Hamburg Germany and led by Kay Tigges, stated that unfortunately up till now; there was no parallel development in the shipping industry to that on land-based sources of air pollution, which has demonstrated remarkable reductions since 2000.

Tigges, an MSc graduate in Naval Architecture and his collaborators foresee in their report under the title, Fuel Savings on Propulsion by Recovery of Thermal Energy – the Most Efficient Opportunity to Protect the Environment, that this state of affairs may change with the up and coming force of the International Maritime Organisation’s (IMO) Rules Annex 6.

As there is a substantial demand on the power installed aboard large (reefer) container vessels, much more than that required before, a modified propulsion plant alternative is proposed in the report. One of their targets is to save energy; to minimise fuel consumption as well as gas emissions.

Another is to give the ship additional power and, by means of a so-called booster device, to increase her speed or to have a supplementary “Sea Margin”. This is particularly important for container ships operating under strict time schedules.

To reach these goals, three main components have been chosen for the proposed alternatives:

Under the leadership of Siemens AG, a group of renowned suppliers has been organised to deliver offers to shipping companies open to such innovations.

The group members are: Aalborg Industries (DK), Peter Brotherhood Ltd. (GB) and Siemens AG (D). Additionally, Wärtsilä Switzerland Ltd. (CH) and MAN-B&W Diesel A/S are associate partners of this group. After analysing and evaluating in-depth developments and efforts on the front of improving energy efficiency on board large cargo vessels, the report sketches an actual scenario for the circumstances under which the shipping industry has to operate. “Protecting the environment, by minimising the impact of growing industrial activities on it, has been finally deeply recognised as essential for the well-being of life on our planet. It is on the agenda of international organisations, governments, political parties, customers and suppliers of goods of any kind.

“Climatic changes and protection of the atmosphere against the harmful gases emitted by diesel engines on board of ships are important items in this train of thought. Of such gases, the main ones are oxides of nitrogen (NOx), sulphur (SOx) and carbon (COx),” the report states.

It goes on to sketch the processes that leads to the international regulatory regimes under which the shipping industry has to operate and states that, “the normal duration of all (these) procedures ... can take many years, such as was the case with the MARPOL [Marine Pollution] Convention, dealing with maritime pollution.

“The MARPOL Convention consists of a number of annexes; each is about a certain topic. For the present study, the most important is in Annex VI, entitled Regulations for the Prevention of Air Pollution from Ships’ which was approved by IMO in September 1997, but first coming into force in May 2005.”

On ships, the sources of emission are the diesel engines, which deliver propulsion and auxiliary power. Unfortunately, all devices and measures used to reduce emissions cost money to be installed and operated. “Until now, owners and operators of ships, with few exceptions, paid only lip service to the necessity of emissions reduction on their ships, because they were aware that it normally takes a long time for the IMO Conventions to come into force and were afraid of the financial consequences involved.

“This situation is changing, because recommendations of the past are becoming current laws now. These days, everybody already speaks about green ships and conferences.”

Several shipping companies are taking advantage of this environmental service and an increasing number of ships carry an Environmental Passport on board issued by Classification Societies.

In this scenario, ship propulsion plants including WHR plants are becoming even more attractive. Emissions from diesel engines are generated during the burning process of the fuel in the combustion chambers of their cylinders. This mainly depends on how much fuel is being burnt and is a function of the propulsion and auxiliary power required on the ship.

“For large (reefer) container ships, the amount of power, respectively emissions, can be impressive. Then logically: A WHR plant adopted primarily to reduce the fuel consumption i.e. operational costs by say 10%, will have a costs free benefit as by-product, consisting of approximately the same amount of emissions reduction,” the report states.

It goes on to list the impact of WHR systems and poses the question whether “one fuel ships” (same fuel for main engine and generation sets can survive.)

The contribution of the WHR systems will gain ground. “But the number of indexed applications has to grow too, in order to facilitate the quantification of the benefits and such developments may take years to be accomplished,” they conclude.