The PSR-DiAvante-Stanford University consortium presented in a workshop in Bogotá the results of their study on auxiliary services for Colombia in an environment of renewable insertion. This study is being carried out for the Colombian Regulator (CREG), with support from the Operator (XM) and the planning agency (UPME). The scope of the study includes the development of integrated generation-transmission expansion plans, with an emphasis on wind power in the Guajira region; the formulation of different market designs for auxiliary services; and the quantitative evaluation of the economic signals and impact of each design on the efficiency of the expansion and operation. The workshop was held on October 31 and had the participation of about one hundred experts from government agencies, companies and universities in the auditorium, in addition to open transmission over the Internet. The presenters for PSR were Silvio Binato and Mario Pereira. After the workshop, the consortium met with the Minister of Energy of Colombia to present the main results of the work.