Turning waste heat into energy - and cutting CO2 emissions at the same time

The Triple-E is the latest in a succession of Maersk Line ves¬sels to be equipped with an energy-saving advanced waste heat recovery system, cutting fuel use and therefore reducing the ship’s CO2 footprint by approximately 9 percent.

Triple-E: Turning waste heat into energy

Adopting a waste heat recovery system captures the heat and pressure contained in the exhaust gas and uses it to move turbines, creating mechanical energy to operate an electrical generator. Without such a system, a quarter of the energy from a vessel’s fuel is lost when an engine’s hot exhaust gas escapes into the atmosphere.

Weighing 75 tonnes and with a 35 square-metre footprint, the waste heat recovery system is a large and complicated piece of mechanical machinery. At a cost of around 10 million US dollars per unit, it isn’t cheap – but there is a long-term benefit from installing it. Depending on the price of oil, Maersk estimates the return on investment of the waste heat recovery system to be in the range of five to 10 years. If oil prices rise, the system will pay off closer to five years.

While oil prices will fluctuate, Maersk’s commitment to the environment is constant. Because of the energy savings and reduced emissions the system provides, the company plans to continue installing this technology on its other vessels. 58 Maersk Line vessels, including the 8 E-class vessels (Emma Maersk), have the system on board. Including the 20 Triple-E vessels, a total of 78 Maersk Line vessels will have the waste heat recov¬ery system installed.


The waste heat recovery system is an integral part of the Triple- E’s energy efficiency. There are costs associated with any upgrades to reduce our fuel consumption and emissions, but in this case the long-term benefits to us, our customers and the environment are worth the extra investment.


FACTS: Waste heat recovery system

  • The waste heat recovery system fitted on each Triple-E vessel ensures that what would be wasted on other ships is another source of power – and it also reduces CO2 emissions by approximately 9 percent.
  • Maersk Line is the first company in the industry to install waste heat recovery systems as standard on all its new ships
    58 Maersk vessels, including the eight E-class vessels, already have a waste heat recovery system fitted. The new 20 Triple-E class vessels will all follow suit. In total, 78 vessels will then soon have the system in place.
  • The price of a waste heat recovery system depends on the size of the main engine. For the Triple-E, the waste heat recovery system cost will be significant at USD 10 million dollars for each vessel.
  • The return on investment time is five to 10 years, depending on fuel price
  • How the waste heat recovery system works: The waste heat recovery system captures the hot exhaust gas emitted from the engine to produce extra energy for propulsion. When exhaust gas leaves the engine, it has a very high heat potential. By utiliing this heat in an exhaust gas boiler, it is possible to generate steam. The waste heat recovery system then supplies the steam to a turbine connected to a generator, which then recovers electrical energy. The engine’s waste heat has been changed into valuable electric power, in the process cutting a ship’s CO2 emissions