Tracking electricity generation attributes can yield detailed information on the used electricity generating technologies, such as per unit fuel consumption and emissions to the environment. The policy context matters for defining the attributes to be tracked. Evolving experience with tracking greatly facilitates the implementation of reliable tracking systems. Some EU Member States have already gained experience with electronically tracked generation attributes for the purpose of disclosing the generation mix to the consumer. Another major application is the use for facilitation of support systems for renewable electricity. There are factors rendering the introduction of tracking generation attributes in Europe no easy task. The main problem is the widely varying initiatives among EU Member States to implement legislation on Guarantees of Origin and disclosure, as this greatly complicates trans-border transfers of generation attributes. The amount of electricity traded makes it difficult to link generation to consumption under "contract-tied tracking", while this is of no concern under "de-linked tracking". The key towards overcoming the aforementioned barriers is harmonisation of schemes for tracking generation attributes. (C) 2007 Elsevier Ltd. All rights reserved.