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Guarantees of origin and their misuse in carbon footprint calculations

In the development of the international standard for product carbon footprint analysis, there are now forces arguing that so-called guarantees of origin (GO)  should be used to calculate the greenhouse gas emissions associated  with electricity. This sound innocuous, but one should not be deceived  by a misleading term! Guarantees of origin are not what they sound to  be: they do not guarantee that the electricity you buy is actually from  the source that it is claimed to be from. GO are papers that are issued  when electricity is produced specifying the source and they can be sold  independent of the physical product. If you are a utility in Malta and  produce all your electricity from an oil fired power plant, you can  still offer your customers clean Norwegian hydropower by buying GOs from  a Norwegian utility! There is no way for the Norwegian hydropower to  travel to Malta, and as a consumer you still get electricity from a  dirty petroleum-fired power plant, but with the electricity you get, for  a small fee, a piece of paper that has originally been issued to a  hydropower producer and that this producer has decided to sell on.

What is the problem with that? Well, a Maltese hotel owner can thus  for a small fee claim to use renewable power in his operations and buy  himself a green image. A carbon footprint label would show that the  hotel has a very low carbon footprint.

Guarantees of Origin for electricity are misleading and should not be  used in LCA or carbon footprint labels. The purpose of life-cycle  assessment (LCA) is to truthfully assess the emissions and resource use  that is associated with a product system, from the extraction of raw  materials to the disposal of the final product. As a scientific tool,  LCA aims to accurately represent the actual connections between  materials and processes along the life cycle and associated emissions,  and to assign these emissions to the product systems that require the  materials or are produced by the processes in question. The use of GOs  in LCA obscures the real connection between electricity production and  the emissions associated with it. It contravenes the purpose of LCA and  carbon footprint labeling and has the potential to discredit it.

I argue that the actual electricity mix of the utility you buy  electricity from should be used for assessments of the carbon footprint,  not some phony papers displaying physically unrealizable electricity  sales.

Why should GOs not be used in LCA and carbon footprint labels? Well,  first, because they systematically give you the wrong answers. If you  stay in the above hotel and choose to keep the AC on all night, more oil  will be burned in the Maltese power plant, causing more CO2 emissions.  This should be truthfully represented by an LCA. Second, because such  labels would lead to the wrong decisions. If the Maltese hotel owner  does an assessment of whether she should in the winter months heat the  Hotel’s swimming pool with electricity or solar collectors, the  assessment would identify electricity as most climate-friendly energy  source. In reality, however, the use of solar heat is clearly much more  climate friendly. Third, because we should not treat electricity  differently from any other inputs in carbon footprinting. For all of  these reasons, we should use the electricity mix of the actual  electricity supplier as a basis for calculating carbon footprints.

About the author

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Edgar Hertwich

I am professor of industrial ecology at the Norwegian University of Science and Technology.

February 15, 2012