Risk-based retrofitting analysis employing the carbon intensity indicator

Abstract

The study employs a risk-based approach for ship propulsion system retrofitting analysis to reduce CO2 emissions and enhancing cost efficiency. The analysis is based on historical data from the EU-MRV database collected for ships operating in the Black Sea using the Carbon Intensity Indicator (CII). Based on the Attained CII/Required CII rate, four levels are identified as critical thresholds and analysed by the Weibull probabilistic model. Additionally, a cost-benefit analysis is performed, accounting for discounted costs related to the initially installed propulsion system supplied by Very Low Sulphur Fuel Oil (VLSFO) and the retrofitted system on Liquefied Natural Gas (LNG), including the cost of the fuel and taxes related to CO2, insurance, maintenance, interest rate, depreciation, resale, and loss of opportunity, conditional on the retrofitting consequences. The cost-benefit and associated risk-based retrofitting analyses are employed to identify the most appropriate retrofitting solution. The Weibull probabilistic model accounts for the enormous uncertainty and variation of the input parameters. The study demonstrates how the data can address critical issues such as condition-based time and the best ship age for retrofitting, accounting for the associated risk. An effort is made to define when to perform retrofitting, reaching a specific ship age accounting for the time needed for retrofitting.