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.