Retrofit Payback

Simple payback and NPV for an energy-saving retrofit - WHR, air lubrication, wind assist, hull coating, battery hybrid. Inputs: capex, annual fuel saved, bunker price, discount rate and project horizon.

LifecycleEconomic

Project

Capital expenditureUSDAnnual extra opex (if any)USD/year

Saving

Fuel savedt/yearBunker priceUSD/tCO₂ avoidedt/yearUsed to value ETS/FuelEU avoided cost.Effective carbon price (ETS + FuelEU)USD/t

Financing

Project horizonyearsDiscount rate%

Annual cash saving

655,000USD

Simple payback

3.1years

NPV at discount rate

2,600,446USD

Accept project

Formula, assumptions, and limits

Positive NPV = the project beats the discount rate. Simple payback ignores the time value of money but remains the most-cited screening number in retrofit board packs.