  As conventional flexibility providers are gradually being replaced by
variable renewable energies and electricity demand keeps rising, additional
flexibility will become increasingly valuable for the power system. Meanwhile,
new sources of flexibility known as distributed energy resources are starting
to emerge. Among them electric vehicles have a promising potential to provide
short-term frequency-control services. However their integration into balancing
markets faces various barriers. Based on the existing literature, this paper
aims at identifying which potential barriers exist in the case of the
participation of electric vehicles in German balancing markets.
