In this paper, we showed the decrease in network delay by using efficient XML interchange (EXI) instead of XML in open automated demand response 2.0 (openADR). Due to large number of devices on the smart grid, when we are dealing with a network constrained systems, the extra file size of XML can be the cause of delay in the system. For this reason, we recommend the use of EXI in openADR 2.0 which not only has a much smaller file size but also it can replace XML without making major modification to the current system. To show the advantage EXI has over XML, we have created a model of the Smart Grid on OPNET and generated traffic based on openADR 2.0 standard and the results show that EXI performs significantly better in a bandwidth constrained system.