For the application of wireless sensor network technology in an energy self-sufficient condition monitoring appliance, we propose a new hybrid network topology to combine the advantages of the ZigBee standard with the need for lowest power consumption when applying an energy harvesting solution for a subset of the sensor nodes. For a research project on a wireless condition monitoring system, we developed a prototype implementation of a partly energy self-sufficient wireless sensor network. We adapted the ZigBee network protocols so that the energy consumption of the self-sufficient nodes is reduced albeit a ZigBee conform communication with the rest of the network is still ensured. In this paper, the prototype system is presented and the problem when applying a full ZigBee stack is stated. We propose to shift parts of the network functionality from the end-devices to the (mains- or battery powered) routers and show actual measurement results and calculated values to indicate the improvements of this adapted hybrid topology.