Planes, trains, trucks and ships keep the global economy moving. But just like with every other mode of transportation, green practices in maritime shipping have grown. This is largely thanks to a worldwide effort to limit emissions and protect marine ecosystems.
At Out2Sea, we know that maritime shipping is the greenest form of transportation available. Believe it or not, airplanes can emit about 500 grams of CO2 per kilometer traveled. Trains and trucks emit anywhere from 30-150. Maritime shipping comes in at a mere 10-40 grams per kilometer.
But while shipping beats out its counterparts, there are still many eco-friendly improvements that need to be made. Thankfully, the green shipping revolution has already begun.
Efficiency in ship design
Limiting energy consumption, preventing catastrophic fuel spills and making propulsion more efficient are all important goals of green shipping that can be solved by efficient ship design. To start, many companies have expanded their use of LED lighting fixtures throughout their ships. These units are significantly less expensive than they used to be, so investing in them makes more sense than ever right now.
Fuel spills can certainly cost shipping companies a lot of money in environmental cleanup costs. “Double hulls” in tugboats and other ships are now being used to limit the threat of an oil spill in the event of an accident. Many ocean class tugs, for example, have hulls made of welded steel, with the oil tanks located inboard of the side shell.
In the realm of ship propulsion, waste-heat recovery systems have become quite common in larger cargo ships as of late. These systems cause ships to use fuel more efficiently by capturing energy in the form of heat from a ship’s exhaust and using it to generate steam. This steam is then used to power the turbine and propel the ship forward.
A growing number of ships around the world are using hybrid technology instead of fossil fuels. These ships – mainly ferries – have “stolen” many of the auto industry’s technological advances.
Some of the hybrid ships in operation are battery-powered, which means they have to plug in and recharge during stops in port. Technology like this can save shipping companies more than 20,000 liters of fuel each year. The big question right now is “how can the maritime industry incorporate the necessary infrastructure on a wide scale?”
In order to make hybrid technology easier for larger ships to use, ports will have to install charging stations for ship batteries. Logistics and transportation companies might not have the appetite to do this right now, but just like in the automobile industry, it’s only a matter of time before hybrid technology becomes “the norm.”
Green shipping and cleaner fuels
To comply with local regulations and to cut greenhouse gas emissions on an international scale, the maritime industry has adopted alternative fuels in certain areas.
While most cargo ships still use bunker fuel – heavy fuel oil that contains high amounts of sulphur – some ships have explored alternatives like liquefied natural gas (LNG) and methanol. The recent abundance of natural gas has made the price of LNG quite cheap. Still, ships need to be retrofitted to store it, and many companies are hesitant to invest this money. Unfortunately, LNG tanks are roughly 3-4 times the size of heavy fuel tanks, so these upfront investments are considerable.
Methanol is a popular alternative to LNG and carries lower retrofitting costs. Just like LNG, it has low sulphur content and produces lower amounts of nitrous oxides during combustion. Although it still has lower energy content compared to heavier oil, the American chemical industry already uses methanol widely. This makes it fairly easy for the shipping industry to take it up as an alternative. In fact, the United States already consumes more than 6 million tons of methanol annually, due to the natural gas revolution.
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