Study says ships are less fuel efficient; operational evidence differs

A study finding that ships built in 2013 are on average 10 percent less fuel efficient than those built in 1990 may be a case of comparing apples to kumquats, according to industry observers.

The study commissioned by environmental lobbying groups Seas At Risk and Transport & Environment, both members of the Clean Shipping Coalition, found that bulk carriers, tankers and containerships built in 2013 are on average 12, 8 and 8 percent less fuel efficient, respectively, than those built in 1990 — ostensibly contradicting industry claims that shipping is becoming more fuel efficient. That assessment is based on the Energy Efficiency Design Index (EEDI), a legally binding standard for new ships built in 2013 or later, overseen by the International Maritime Organization (IMO).

The EEDI measures the inherent design efficiency of a vessel moving a given cargo volume over a given distance. Starting in 2015, ships have to perform 10 percent better than 1999-2008 reference vessels. In 2020, they have to perform 20 percent better and in 2025, the EEDI has to be 30 percent better.

The study’s author, Jasper Faber from CE Delft, a independent research consultancy, acknowledged his study covered only design efficiency and did not take into account operational fuel efficiency from more efficient engines, nor the fleet average due to the growth in the size of vessels, especially containerships.

Shipping industry insiders and environmentalists agree, saying the report’s limited conclusion isn’t the whole marine environmental story. The International Chamber of Shipping (ICS) called Transport & Environment’s claim that modern ships are less CO2 efficient than those built over 20 years ago “fanciful.” ICS noted that the latest IMO Greenhouse Gas Study, published in 2014, shows that international shipping reduced its total CO2 emissions by more than 10 percent between 2007 and 2012, even though maritime transport increased during that period.

Elena Craft, a research scientist with the Environmental Defense Fund, a U.S.-based affiliate of the Clean Shipping Coalition, agreed with the ICS assessment.

“They do have a point in that it hasn’t really been that long that ships were required to meet the EEDI that went into effect in 2013,” Craft said. “That’s not necessarily a long enough time to make an adequate assessment of the entire fleet, and there’s so much that changes, even operationally, in how a ship moves that can influence the emissions.”

A more useful measurement is the one used by the Clean Cargo Working Group, according to Lee Kindberg, director of environment and sustainability for North America for Maersk Line. It takes into account the fuel consumed for a year, the distance steamed and the cargo moved to calculate carbon emissions in grams per container per kilometer.

That’s the calculation the industry has agreed to use for supply chain metrics so companies that ship by vessel can manage their carbon footprint and make targets to reduce it, Kindberg said.

For example, Maersk Line has reduced its carbon output per container per kilometer — and fuel usage — by 40 percent since 2007, Kindberg said.

“To us, that measurement is more operationally effective in terms of being able to address the carbon footprint of shipping based on real-world values,” she said.

Kindberg said the last 80 or so vessels Maersk has built have used waste heat recovery and other technologies to reduce fuel consumption, and the company is testing a diesel scrubber system on one vessel.

But even as carriers like Maersk Line invest in technologies to reduce energy consumption and emissions, Faber estimates CO2 emissions are expected to rise at least 50 percent by 2050 despite fleet average efficiency improvements of about 40 percent.

Given the international nature of shipping it can be difficult to impose standards on all vessels.

“We’re interested in developing a reasonable model like the one that’s been put forward for the aviation sector to address emissions on a global scale,” Craft said. “Because we’re clearly not going to be able to ameliorate the large increase we’re anticipating unless we do more than what’s being done right now."

By Professional Mariner Staff