Operating energy grids with a high share of renewable en-ergy sources (RES) requires system reconfiguration as aresponse to environmental condition changes. To under-stand them better, simulations are needed and Modelica isan excellent choice for that. Energy grids with event-basedreconfigurations are an instance of variable structure sys-tems (VSS). However, the full support of VSS in Mod-elica is challenging and topic of ongoing research. Petrinets (PNs) offer a formalism for modeling VSS. The ca-pability to simulate PNs in Modelica gives an opportunityto model VSS in Modelica. This paper presents an ap-proach to utilize PNs in Modelica for modeling variablestructure energy grids. Therefore, we introduce energeticPetri nets, a special type of PNs and an experimental li-brary called PNRG for PN-based energy system modelingis presented. Furthermore, possibilities and limits of mod-eling VSS energy grids are discussed and an outlook howto develop this technique is provided.