The global shipping sector currently contributes about 2.5–3% to global CO2 emissions. Within the EU, the maritime sector makes up about 14% of greenhouse gas emissions from the transportation industry. In port areas, ships are one of the largest air polluters (CO2, Sox, NOx, particles). IMO introduced a new Energy Efficiency eXisting ship Index (EEXI) that poses a challenge for ship owners. Significant increases in fuel prices put additional stress on ship owners to find options to reduce energy expenses.