As the international community struggles to reach consensus on how to address climate change, shipping is coming under increasing pressure to do its part. The CO2 emissions from the fuels commonly used by shipping correspond directly to the amount of fuel burned. Transitioning to low- or zero-carbon fuels is therefore a long-term challenge for shipping, while immediate benefits can be achieved by improving energy efficiency. This is now materialising through both regulations and stakeholder demands for increasingly energy efficient shipping.
The first formal regulations on CO2 were adopted by IMO in 2011. These comprise the Energy Efficiency Design Index (EEDI) and the Ship Energy Efficiency Management Plan (SEEMP), both of which will enter into force on 1 January 2013.
The EEDI is a mathematical formula that provides a specific energy-efficiency figure for an individual ship design, expressed in grams of CO2 per ship's capacity-mile, e.g. tonne-mile. A smaller EEDI value means a more energy-efficient ship design. The EEDI applies to newbuilds only.
The SEEMP provides an approach for monitoring ship and fleet efficiency performance over time, and encourages the ship owner, at each stage of the plan, to consider new technologies and practices when seeking to optimise ship performance. The SEEMP will be mandatory for all vessels.
In addition to mandatory regulations, IMO has established the Energy Efficiency Operational Indicator (EEOI). This is a voluntary guideline allowing ship operators to calculate the operational CO2 emissions per tonne-mile. It is considered a tool for benchmarking a ship's performance over time and also allows comparison with other similar ships. The EEOI, or other similar monitoring approaches, are to be included in the SEEMP. Parts of the international community consider these regulations insufficient. There is therefore a strong political drive to regulate shipping further, e.g. through regional or international Market Based Measures (MBM). Proposals under review range from a contribution or levy on CO2 emissions from shipping, via emission trading systems to schemes based on ship efficiency. If agreed, MBMs may appear towards the end of this decade.
Commercial requirements as to energy efficiency are becoming increasingly important. The creation of various voluntary rating schemes for environmental performance, including CO2 performance, are providing tools that allow charterers and cargo owners to use only ships that satisfy their requirements.
|Ship design measures||A sound basis for higher operational efficiency||Charter rates may not reward good designs. A good design can still be operated badly|
|Ship operation measures||Low cost with potential high savings||Difficult to measure effectiveness|
|Port operations||The minimisation of time waiting at or in port through just-in-time arrivals can allow speed optimisation||Ship-port coordination is challeging|
|Alternative fuels||A lower carbon footprint means less CO2emissions||May require significant engine and tank modification. Availability and pricing of new fuel|
|Speed reduction||Low investment and technical adjustments||May lead to requirements for more ships. Potential reduction of ship revenue|