The increase in trade among nations specially of liquid commodity (crude oil, diesel, other chemicals) have come with an increase in incidents of fault leakages in the containers of the vessels carrying the goods resulting in large oil spills, illegal oil tapping cases in recent times have further worsened the situation of oil produces with pipeline rupturing cases adding to the demand of an automated system which could sense the proximity environment and report to the concerned authorities about an alarming situation. One such feasible and effective solution involves integration of various technologies. SDN advocates shifting the control plane to a remote centralized device or application called as controller. The controller is responsible for selecting the shortest routing path to forward the packets using the Optimal path selection algorithm .The coupling of data and control plane on the same device makes it cumbersome to develop new applications and to modify the existing network configuration . SDN has been proved to improve the manageability and efficiency of the network in recent times. The ever increasing internet devices are forcing IoT applications to use cloud services more and more, thus integration IoT and cloud is far or less demanding. Thus there is a requirement of a middleware which could provide compatibility for both platforms. The Openflow protocol allows a network to control the IoT devices employed in multi-tenant and cloud based deployments. The WSN sensors need to read analog values continuously and autonomously for long time of periods. Its impractical to replace batteries in those sensors and some hostile environment makes it impossible. The energy saving schemes must be application specific rather than cost oriented. This paper highlights the steps involved in creating a virtual software defined network using a network emulator called mininet. A real time experimental setup using Arduino board and IoT sensors which senses any leakage or spill and writes the data to the cloud which is eventually read by the virtual hosts in the SDN. This is followed by evaluation of various network topologies and energy-saving techniques in our wireless sensor network.