Tradable Green-power Certificates (TGC) systems resemble greenhouse Emission-permits Trading Systems (ETS). In Europe they both emerged in the period 1999-2001, based on similar beliefs in ‘constructed markets solve public policy problems’. In 2001 TGC were launched under impulse of the European Commission (EC). The systems’ design, attributes and performance were known in 2005 (start ETS phase 1) and more documented in 2008 (start ETS phase 2). Detailed year-by-year follow-up of the Flanders (Belgium) TGC system, revealed major flaws of the experiment, such as: neglect of proper market segmentation, excessive financial transfers from small electricity consumers to renewable electricity generators, lacking innovation incentives, target fetishism. Instead of evolving to a workable market, the TGC system metamorphosed in assignment of certificates case-by-case, mainly to large-scale RE generation projects set up by influential project promoters. The EU ETS exposes similar flaws. There is no evidence the EC has taken advantage of prolific comparative analysis and advanced comprehension of the TGC market construction trials and failures. The EC – deliberately or unconcernedly – skipped the opportunity of learning.