Thanks to new technological advancements and EU policy impulse, distributed energy resources (DER) are poised to become a viable alternative to conventional electricity generation for the provision of balancing services to transmission system operators. In this paper we show that the design variables that affect DER access to and participation in the organized balancing market include different features of auction configuration as well as a number of formal, administrative and technical aspects of market design. In a comparative case study of the balancing markets in Austria, Germany and the Netherlands, we determine the extent to which a given market design effectively facilitates DER participation. To structure this analysis, we designed ...