To be integrated into the IEC 61970-based K-Grid, application of open communication protocol and sub-system modeling to major nodes is needed. In this paper, a module which links load nodes in customers to CIM based on psXML/oBIX, one of open protocols, was developed and data modeling and communication protocols of IEC 61850-7-42 based DER and ESS which apply the module to the customers who have DER and ESS were designed. Also the XML-based distributed database middleware was designed. The proposed modeling and protocols were applied to the building in which commercial DER products and the effectiveness of the proposed data modeling and the communication protocol were evaluated.