EPRI defines a three-phase initiative for an integrated grid

The Electric Power Research Institute (EPRI) has created a three-phase initiative for realizing the full value of central and distributed energy resources (DER). The goal of the initiative is to help identifying the technological innovations needed and to provide the stakeholders with guidelines and tools for the implementation of these technologies. Four key areas have been identified: interconnection rules, advanced distribution technologies, such as smart invertors, planning and operation, and policy and regulation.

The document analyses the experiences of the rapid deployment of PV in Germany. This has led to several technical challenges, which were not fully anticipated. These challenges include local over-voltages on distribution feeders, increased variability and uncertainty on the supply side and a lack of stabilizing inertia. In order to cope with the increased cost of maintaining the distribution grid, the German policymakers approved a new charge on self-consumption of solar generated electricity. This is to ensure that consumers with an average consumption of zero (e.g. by injecting power during the day and drawing power in the evening) still pay for the fixed costs of the utilities.

The current and projected expansion of DER all over the world will significantly change the technical, operational, environmental, and financial characteristics of the electricity sector. The three-phase initiative from the report aims at providing the knowledge, information, and tools that will inform key stakeholders on the transformation of the power system.

Phase I consists of a concept paper (this document) to align the various stakeholders from the electricity sector (e.g. utilities, regulatory agencies and non-governmental organizations) and provide them with examples to support an open fact-based discussion.

Phase II consists of a six-month project that will develop a framework for assessing the costs and benefits of different technologies that lead to a more integrated grid. The objective is to provide discuss support policy and regulatory aspects in order to enable integrated grid solutions.

Phase III conducts a global demonstration project to provide guidelines that the different stakeholders can use for the system-wide implementation of integrated grid technologies in the most cost-effective manner.

An integrated grid that enables a higher penetration of DER offers benefits to operators, customers, and society, which include

• DER can provide distribution voltage support, provided there are effective interconnection rules and smart invertors.
• The installation of DER can defer the need for capacity upgrades for generation, transmission and/or distribution systems.
• DER can improve system resiliency by supporting portions of the distribution system during outages, which requires a seamless integration of the existing grid and DER.
•  DER can reduce the environmental impact by reducing the need for emissions-producing backup generation. Also the aggregation of low-emission DER, such as combined heat and power units, energy storage and demand response contribute to this.

As the electric power system is undergoing a paradigm shift due to the increasing share of DER and the electrification of heating and transport, these types of initiatives provide valuable information for the various stakeholders in the electricity sector. The report aims at developing a global collaborative approach to develop a comprehensive repository for data and information that can be used to move towards the integrated grid.

> More information: http://www.epri.com/Our-Work/Pages/Integrated-Grid.aspx