Regulations on Energy Efficiency of Ships
Indra Nath Bose, Head - Quality, Safety & Training The Great Eastern Shipping Co Ltd

Aiming to reduce Green House Gas (GHG) emissions from ships and increase the energy efficiency of ships, Marine Environment Protection Committee of International Maritime Organisation (IMO) has adopted two major initiatives in July 2011 - Energy Efficiency Design Index (EEDI) for new ships and Ship Energy Efficiency Management Plan (SEEMP) for all ships - which have entered into force from January 2013. While the EEDI is in the hands of the shipbuilder, or the designer, the Ship Energy Efficiency Management is in the hands of the ship operator and the Charterer. The paper explores the various aspects of deploying the application of EEDI for all new ships and SEEMP for all existing ships in reducing Carbon Dioxide (CO2) emissions and saving fuel cost from international shipping for every year up to year 2030.

Marine Environment Protection Committee of International Maritime Organisation in July 2011 has adopted a set of technical requirements aimed to reduce Green House Gas (GHG) emissions from ships which includes two types of measures (1) Energy Efficiency Design Index (EEDI) for new ships and (2) Ship Energy Efficiency Management Plan (SEEMP) for all ships. These regulations have entered into force since 1st January 2013.

While the EEDI is in the hands of the shipbuilder, or the designer, the Ship Energy Efficiency Management is in the hands of the ship operator and the Charterer. Technical design measures include the use of non-fossil fuels as well as further optimisation of engines, hull, and propeller. Operational measures include, inter alia, better utilisation of cargo capacity, better voyage planning to strike the right balance between times spent underway and fuel consumption, and enhanced energy efficiency in ship operation.

Drawing an obvious parallel with the car industry, the technical design measures are clearly in the hands of the car manufacturer. The manufacturer can optimise the design for better fuel economy, test it under certain standardised design conditions, label it, and use this information to increase car sales. Merely because technical design measures and operational measures are separated, the customer is able to compare the standardised fuel economy of various cars, when choosing, and regulators are in a position to set minimum standards. Operational measures are in the hands of the consumer and stimulated by other means.

Study on IMO Energy Efficiency Measures
As per a study commissioned by IMO (MEPC 63/INF.2 dated 31 October 2011), it is estimated that application of the EEDI for all new ships and SEEMP for all existing ships will reduce approximately 150 M tonnes of CO2 from the atmosphere annually by 2020, depending on the growth in world trade. For 2030, the reduction will be approximately 330 M tonnes annually. The average annual fuel cost saving is estimated between USD 20 and USD 80 billion (average USD 50 billion) by 2020, and between USD 90 and USD 310 billion (average USD 200 billion) by 2030.

Energy Efficiency Design Index (EEDI)
The basic idea of the EEDI is to give each and every new vessel a calculable figure that will denote its emissions of CO2 in relation to the amount of tonne-mile of cargo carried. It is not unlike the ratings given to fridges and cars today.

Consider the following simplified EEDI formula: the CO2 emission represents the total CO2 emission from combustion of fuel, including propulsion and auxiliary engine sea load, taking into account the carbon content of the fuels in question. If innovative energy-efficient technologies are incorporated on a ship, their effects are deducted from the total CO2 emission. The energy saved by the use of renewable sources of energy e.g., wind or solar energy is also deducted from the total CO2 emissions based on actual efficiency of the systems. The transport work is calculated by multiplying the ship’s capacity (deadweight), as designed, by the ship’s design speed measured at the maximum design deadweight condition and at 75 per cent of the rated installed main propulsion engines.

Denoted in grammes of CO2 emitted per tonne nautical mile (the emissions from taking a tonne of cargo one nautical mile) the figure should be below a relevant benchmark for the specific ship type and size. The bench mark is established from the corresponding average figures of existing ships of specific type and size.

Vessels that exceed this benchmark figure and are therefore heavier polluters will not be certified to operate. The figure for the benchmark will then be lowered over time as new technology provides the capabilities for more energy efficient ships to be built.

Indeed, the first iteration of the EEDI has been developed for the largest and most energy-intensive segments of the world merchant fleet, thus embracing 72 per cent of emissions from new ships and covering ship types: oil and gas tankers, bulk carriers, general cargo ships, refrigerated cargo carriers and containerships.

It is a non-prescriptive mechanism that leaves the choice of what technologies to use in a ship design to the stakeholders, as long as the required energy-efficiency level is attained, enabling the most cost efficient solutions to be used.

The EEDI formula, as currently drafted, is not supposed to be applicable to all ships, as it is explicitly recognised it is not suitable for certain ship types, e.g. ro-ro vessels and for ships with diesel-electric, turbine or hybrid propulsion systems.

Suitable EEDI regulations for ship types not covered by current regulatory regime has been now developed and scheduled to be adopted in 2014 at 66th Session of MEPC to address the largest emitters among those first namely, Ro-ro cargo ship (vehicle carrier), Ro-ro cargo ship, and Ro-ro passenger ship; Cruise passenger ship having non-conventional propulsion and LNG carrier with (Dual Fuel Diesel – Electronic (DFDE) propulsion and steam turbine propulsion).

Ship Energy Efficiency Management Plan (SEEMP)
Ship Energy Efficiency Management Plan (SEEMP) is a ship specific system to be used by ship operators to enhance the energy efficiency and the emissions performance of their ships by applying identified technical and operational measures to improve fuel efficiency. The SEEMP seeks to improve a ship’s energy efficiency through four steps: Planning, Implementation, Monitoring and Self-evaluation & Improvement.

These components play a critical role in the continuous cycle to improve ship energy management. With each iteration of the cycle, some elements of the SEEMP will necessarily change while others may remain as before. SEEMP of a ship should contain measures identified for improving her energy efficiency along with identification of person(s) responsible for implementation, method of monitoring of status and periodicity of such monitoring. Measures to improve energy efficiency of existing ships could be (a) operational in nature e.g., improved voyage planning, weather routeing, speed optimisation, optimum trim, hull and propeller cleaning etc as well as (b) technical in nature e.g., fitment of appendages for improvement of ship’s propulsion efficiency, application of low friction hull coating etc.

Technical Measures to Improve Efficiency of Ships & Achieve Required EEDI

The energy efficiency of new ships is measured by Energy Efficiency Design Index (EEDI), which should be calculated in accordance with Guideline on the method of calculation of the attained energy efficiency design index (EEDI) for new ships - Resolution MEPC.XX(63) developed by the IMO.

In considering how to improve the efficiency of ships, it is important to understand the relationship between EEDI and efficiency improvement measures, i.e., how each improvement measure affects the EEDI. Figure 1 illustrates the relationship between EEDI and improvement measures. Simply put, there are three approaches to improve the value of EEDI:

(a) DWT Enlargement
(b) Speed Reduction
(c) Application of New Technologies

DWT Enlargement: Although larger DWT (deadweight tonnage) requires larger engine power, DWT enlargement can improve the efficiency i.e., reduce the value of EEDI. This is because, generally speaking, the necessary engine power increases in proportion to the DWT increase powered by two-third, and therefore the increase of the denominator outweighs that of the numerator. It should be noted that, while DWT enlargement improves the efficiency and lowers the EEDI of a ship, the ship would be subject to lower (more stringent) Required-EEDI.

Speed Reduction: Lowering the speed would reduce the necessary engine power considerably as the engine power is in proportion to the speed powered by three. Thus, speed reduction is very effective in improving the efficiency.

Application of New Technologies: New technology here means one which can be considered as technically achievable and be applicable to a particular ship type from an engineering viewpoint.

The advantage of application of new technology is that it can improve the EEDI without changing DWT or ship speed; the improvement of the efficiency would not cause any changes to, or constraints on, the operation patterns of the ship.