that some ports opt for both fixed and mobile installations. Interestingly, 29% of the
ports seem to be planning to provide OPS in the next couple of years.
These results offer encouraging perspectives for the particular measure. However,
the price differential between electricity and marine fuel and increased investment
Table 11.7 Differentiated fees for ‘greener vessels’. (Source: ESPO (2019))
11 New Challenges and Opportunities for Sustainable Ports: The Deep Demonstration. . . 193