The idea doesn't require any modification to the ships, just a large dollop of common sense and joined up thinking. First trials demonstrate a nearly 25 percent reduction in emissions.
Shipping is an extremely efficient way to move bulk goods around the planet, but it's responsible for a similar amount of global man-made CO2 emissions as the aviation industry (3% to 4%), and the unique energy requirements of long-haul cargo ships make them extremely difficult to decarbonize. However, the good news is that the 'Blue Visby Solution' offers enormous fuel and emissions savings for cargo ships worldwide, simply by being smarter about speed and timing and eliminating inefficiencies.
Currently, according to the Blue Visby team, most cargo ships follow an operational practice known as "sail fast, then wait". That is, they go as quickly as they can from port A to port B, regardless of what the schedule's looking like at their destination. When they get there, they sit still and wait at idle, continuing to burn fuel, until it's time for them to dock and load/unload their cargo.
Whilst the Blue Visby Solution requires considerable connectivity, co-ordination and participation from lots of different stakeholders around the world, it's a remarkably simple solution: it just tells the ships to slow down, so they arrive at port right on time.
Pushing all that bulk through the water at a slower speed cuts down hugely on hydrodynamic drag, so the engines burn considerably less fuel, with a corresponding drop in emissions. And the cargo delivery speed is totally unaffected; the ships still load and unload at exactly the same times.
The Blue Visby team studied the movements of 3,651 Panamax vessels taking 20,580 trips and estimate that their brilliantly simple timing tweaks could cut emissions by an average of 23.2 percent without affecting customer outcomes.