Energy consumption in Wireless Sensor Networks (WSNs) is a limiting factor that hinders the application of such networks into solving a broader set of problems. Various ways of saving energy have been proposed, from energy efficient processing to power aware cluster organization. With communication between nodes being responsible for a large part of the energetic demand, energy efficient methods of communication have been proposed, with multi-hop communication being a wide used technique, capable of minimizing energy consumption and spreading it amongst the network. However, multi-hop is not always more efficient and is prone to a high delay, due to the decode and forward mechanism usually employed. In this paper a cooperative MIMO technique is studied, its energy consumption analyzed, and a mechanism for integrating it in existing WSNs and allowing its coexistence with multi-hop communication is suggested. Energy efficiency, packet delivery delay and packet loss ratios are analyzed and the results compared to standard WSNs.