Category 18 April 2019

An energy efficient container ship

The Triple-E is the world's largest and most efficient vessel. The vessel reduces emissions and fuel consumption through the combination of its two engines, efficient shape and an advanced waste heat recovery system. The combination of these factors can reduce CO2 emissions by 50 percent per container moved, compared to industry average on the Asia-Europe trade.

The challenge

The interest in energy efficiency has been growing due to increased oil prices and climate change. There is an interest in developing more efficient vessels to reduce CO2 emissions from the shipping industry and thus reduce the environmental impact.

The innovation

When designing Triple-E, economies of scale, energy efficiency and reduced environmental impact was taken into account.

At high level the development of Triple-E has been made by Maersk Line, located in Denmark.

The vessel is one of the world's largest container ships, designed and optimized to deliver more cargo - while using less fuel - at lower cost. The vessel has an energy efficient design with an enlarged cavity that gives the Triple-E 16 percent higher capacity than Maersk’s previous largest vessel, Emma Maersk. The inside cavity can be filled with 2500 extra containers despite little change in the length and breadth of the ship.  The vessel has also a U-shape instead of the traditional V-shape, allowing room for more containers. A U-shaped vessel would usually cause more resistance in the water but not in this case, due the lower speed of the ship. A combination of two smaller engines and two propels allows a lower number of revolutions that result in energy savings of 10 percent and a sustainable transport.   Triple-E is equipped with double engines that are limited to a top speed of 23 knots and can run on low as 80 revolutions per minute, compared to Emma Maersk which has a top speed of 25 knots and requires 90 revolutions per minute. This makes the Triple-E more fuel efficient than the Emma Maersk and then offsets the increased resistance from the shape. The vessel is also equipped with a waste heat recovery system that captures heat and pressure in the exhaust gases and uses them to move turbines. This creates mechanical energy that can drive an electric generator and thus provide additional energy for propulsion, reducing CO2 emissions by 9 percent. Many different parties have been involved in the development and sub suppliers have provided input and expertise knowledge. The manufacturing of the energy efficiency vessel was carried out by South Korea's Daewoo Shipbuilding & Marine Engineering (DSME). The cost of the development has been covered by the individual parties themselves (venture capital for development, demonstration and commercial exploitation).

Why did it work?

The Triple-E has a highly efficient engines but the design of the hull is the most significant factor which makes the ship so effective, despite its size.

Further deployment

The technology has been proven to work in its final form under expected conditions. Hence the technology reaches level 8 on the TRL scale.