  Strong digitalization and shifting from unidirectional to bidirectional
topology have transformed the electrical grid into a cyber-physical energy
system, i.e. smart grid, with strong interdependency among various domains. It
is mandatory to develop a comprehensive and holistic validation approach for
such large scale system. However, a single research infrastructure may not have
sufficient expertise and equipment for such test, without huge or eventually
unfeasible investment. In this paper, we propose another adequate approach:
connecting existing and established infrastructures with complementary
specialization and facilities into a cross-infrastructure holistic experiment.
The proposition enables testing of CPES assessment research in near real-world
scenario without significant investment while efficiently exploiting the
existing infrastructures. Hybrid cloud based architecture is considered as the
support for such setup and the design of cross-infrastructure experiment is
also covered.
