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How 'gray energy' is underestimated

Melina Grundmann
April 5, 2018

Although we can't see it, gray energy is key to measuring our ecological footprint. Researchers in Europe are arguing that we need to better tally gray energy in order to present a more complete picture of energy use.

black and white photo: Wind turbines standing on a field
Wind turbines Image: picture-alliance/chromorange/K. H. Spremberg

Although gray energy is a term most people have never heard of, it is everywhere: in the water we drink, in the smartphones we use, and in the cars we drive. Gray energy means the sum of all the energy required to produce a product.

Experts say it's time for us to be aware of this embodied energy, since it typically at least doubles the energy of a product. 

As buildings are are the biggest consumer of energy in Europe, reseachers now argue that more than half of a low-energy building’s environmental impact has occurred before it was even occupied, due to gray energy. Not taking this into account distorts the picture around energy use.

A paper written for the EU's Science for Environmental Policy explains how we need to focus on those impacts. The researchers recommend "expanding the environmental assessment of buildings from just the operational stage of a building’s life, when it is in use, to include production and transport of materials, construction activities and building maintenance." 

In other areas, too, taking gray energy into consideration could help make a significant contribution to saving energy.