The growth in container volumes over the last decades means an increase in container handling at terminals around the world. Notwithstanding the economic benefits, container handling causes additional pressure on the surrounding infrastructure and the environment. This is happening precisely at a time when environmental issues, in particular CO2 emissions, are the main concern of the energy and climate change debate. Although not specialized in the field of energy consumption, many policymakers and managers need to make decisions about reducing CO2 emission. This paper provides a six-step approach to make energy consumption (and hence CO2 emissions) easily transparent. The pproach is illustrated using the energy consumption of yard lighting. It can be concluded that our first attempt to understand the energy consumption of yard lightning gives promising results that can contribute to an improved benchmark for the CEN EN 16258 standard.@en