The world is shifting to the usage of more distributed generation (DG) where DG systems are much smaller and decentralized sources rather than the traditional power plants. Hence, system operators on the distribution side are trying to create their own standards or embrace international standards for DG connection. At this point in time, the only Australian standard for connections of DGs is AS4777 covering 200kW and below, any connections greater than 5MW is governed by the National Electricity Rules. This means that any embedded generator seeking a connection between 200kW-5MW is currently required to meet jurisdictional standards not only for each state but each distribution utility.

The lack of a consistent national standard creates uncertainties around DG connection requirements and leads to much high compliance costs for generator developers and high assessment efforts for distribution networks. Therefore, an Australian Standard for the connection of mid-scale embedded generation is expected to make a significant advancement to addressing inefficiencies and will have several benefits for both distribution network service providers and renewable energy developers.

As part of a project that received funding from ARENA under the Advancing Renewable Programme, NOJA Power will collaborate with utilities and key stakeholders to produce an Australian Standard for mid-scale DG connection to the distribution grid. It will be based on international standard adoption and experiences learned and feedback received from local installations.

This paper presents the project plan and covers findings from reviewing Australian connection guidelines and main international standards namely: IEEE 1547, IEC 62786, EREC G59/3-2 and TS 50549-2. It discusses common areas and differences between these standards and connection guidelines. It also explains the significance of using a unified standard and provides some recommendations that can be incorporated into the Australian standard for mid-scale DG connection.