Electric Dipole Moments (EDMs) of subatomic particles, are
considered as one of the most powerful tools to study CP-violation beyond the Standard Model.
Such CP-violating mechanisms are searched for to
explain the dominance of matter over anti-matter in our universe.
This paper discusses EDM searches of charged hadrons in storage rings.

The document focuses on activities at the existing storage ring COSY at Forschungszentrum J\"ulich, Germany
and the design of a 100\,m circumference prototype ring able to demonstrate
key technologies and components. These include simultaneous clockwise and counter-clockwise beam operation
with electrostatic bending elements and, by adding a magnetic field, the frozen spin technique.

These proceedings are identical to proceedings submitted to the
\enquote{The 24th International Spin Symposium}, 18-22 October 2021
Matsue, Shimane Prefecture, Japan.