Sharrow: Propelling the shipping industry towards a greener future
A product image of the new Sharrow MX propeller (Image Source: Sharrow Marine).
By Will Denny
When considering the sorts of complex mechanisms which keep our vast global economy running, the container ship industry is a factor that is seldom mentioned. Throughout all hours of the day, 365 days a year, a massive network of skyscraper-sized container ships is perpetually in motion, traveling around the globe to bring us our goods as efficiently as possible. When this system works, it works—we don't tend to hear too much about the logistics of shipping, and it's only when catastrophic disasters, à la the great Suez Canal blockage of 2021 (which resulted in economic disruption of nearly $10 billion) that the true magnitude of the shipping industry is ever truly acknowledged. And of course, with big ships comes big environmental impact, and as the disastrous impacts of the climate crisis continue to rage on, more and more attention must be put towards the energy efficiency of the global shipping industry. For example, in 2020 ships consumed over 200 million metric tons of fuel oils, diesel, and Liquefied Natural Gas (LNG).
Fortunately, although the quantities and scale are staggering, there is certainly still hope as a number of fuel efficiency improvements have been made to these operations already. The graph above reveals that overall consumption of fuel in ships decreased by over 10 million metric tons between 2019 and 2020. More importantly, regulation has led to a dramatic shift in the type of fuels being used as well, with heavy fuel oil (HFO) usage decreasing significantly, in favor of relatively less-polluting light fuel oil instead. In 2020, the International Maritime Organization put a cap on the sulfur content of maritime fuels, leading to this reduction in the usage of heavy fuel oil and increased adoption of sulfur-scrubbing technology. Heavy fuel oils are derived from the byproducts of refining petroleum, for use mainly as a marine fuel. This class of fuel is of particular concern for climate change as they are high in sulfur content, and produce the most Black Carbon (soot-like particles of pure carbon) of any fuel burned in a ship engine. Black Carbon has been described as the second largest contributor to climate change behind only CO2, yet it has a short lifespan of just a few weeks in the atmosphere compared to the 300-1000 year lifespan of CO2, meaning changes in our behavior can have a much quicker impact.
Furthermore, recent technological innovations represent a shining beam of hope in terms of re-adapting container ships for climate change, with a prime example being a new development by Sharrow Marine, appropriately titled the Sharrow Propeller, which sought to redesign the wheel with their new industry standard for marine propulsion. Experiments conducted comparing the Sharrow propeller to current competitors have already revealed glowing results, illustrating dramatic increases in fuel efficiency. For example, one test showed a conventional propeller could achieve 17.7 nautical MPH when running at 3400 RPM, while the Sharrow propeller achieved 22.9 nautical MPH running at 3400 RPM. This 29% increase in speed with the engine running at the same power (RPM) means the ship will reach port faster, while also consuming 29% less fuel along the way if it runs at 3400 RPM throughout the whole trip. The Sharrow propeller does not create a flat increase in speed of 29%, but rather it creates varying increases in speed depending on how fast the boat’s engine is running. This does make it very difficult to calculate the effect that swapping out the propellers of container ships would have on total fuel consumption for a trip. Regardless, this new technology still presents much opportunity for increasing fuel efficiency of vessels. Although the Sharrow propeller was originally designed with smaller boats in mind, the technology presents a promising means for quickly and efficiently reducing the monstrous fuel consumption of the now-common titanic-sized container ships.
Of course, designing these sustainable alternatives for energy and transportation comes with a great financial investment—the Sharrow propeller, just like with solar or wind farms, demands a substantial initial cost to get things running. However, these solutions are not only more financially sound in the long run, but are also necessary for mitigating the ongoing climate disaster. Unfortunately, industry cannot be expected to enact radical changes all by themselves. The goal of creating a better future for everyone must also be supported by everyone, from corporations and shareholders to policy makers, or you and I, looking up at the glowing numbers above the gas pump. Creating new incentives for environmentally friendly practices and new research, through subsidies, could quickly make change. Higher fuel or emissions taxes could quickly facilitate the larger adoption of all of these technologies by rewriting the economic calculus that determines the extent to which they are used. That being said, as the recent explosion in gas prices has taught us, we have not yet adequately shifted our expectations of consumption and government policy to align with the future we want for our children and grandchildren. All of us must live up to the challenge of climate change by embracing innovation and transformation today for the sake of a better tomorrow.
Will Denny is a senior from Connecticut studying economics at NYU, with a deep interest in the intersection between energy, financial markets, and macroeconomics. Will loves his dog Skip, and enjoys playing video games when given the chance.
