The Bureau Veritas Green Rating Composite Index is built on two indexes which bring together a set of measurable variables in two ways. The indexes measure five variables:
1. Energy performance(in kJ/tonne/mile or kJ/passenger/cruise day)
2. Greenhouse gas emissions (in kg/tonne/mile or kg/passenger/cruise day)
3. SOX emissions (in kg/tonne/mile or kg/passenger/cruise day)
4. NOX emissions (in kg/tonne/mile or kg/passenger/cruise day)
5. The period the vessel can operate without discharge of fluids such as black water or grey water.
These variables are first calculated using the ship’s design performance criteria for a set of recognised standard operating conditions and combined to produce an Intrinsic Index. This Intrinsic Index figure can then be used to compare all vessels on a like for like basis, as the calculations always refer to the same standard operating conditions.
Separately all the variables are also measured in service for the actual trade routes or real operational profile of the vessel. The measured values are combined to produce an Actual Index. This can be compared with the more theoretical standard situation of the Intrinsic Index.
Both Indexes can be used to calculate the effects and benefits of different potential investments in green technology, such as scrubbing, new waste handling plant or fuel consumption reducing measures. That provides a better estimate of the relevant investment payback for any potential green investment.
Says Chaléat, “We have seen these indexes work in other industries, now it is time for shipping to take this up. We can help ship users compare ships, help owners who have invested in green technology to prosper in the market place and help owners who wish to invest and upgrade their vessels or change operational practices to target their investments where they will do most good. And also help of them to quantify, accelerate and publicise the results of their efforts to be more environmental friendly and energy efficient.”