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Technical Guideline for the Interconnection of Distributed Energy Resources to EDTI's Distribution System

January 05, 2017

EPCOR acknowledges the use of other documents developed by the utility industry and industry committees as the framework and sources in producing this technical guideline.


A distributed energy resource (DER) is any technology that produces power and is connected to an electric distribution system (including, but not limited to, distributed generation, microgeneration and battery energy resources).1 A DER can use a variety of energy sources, including, but not limited to, liquid petroleum fuels, biofuels, natural gas, solar, hydro, wind and geothermal. Electricity storage devices are also DERs.

This guideline establishes criteria and requirements for the interconnection of DERs within the electric distribution system of EPCOR Distribution and Transmission Inc. (EDTI). Specifically, this guideline defines the technical requirements for connecting DERs that are not exclusively owned by EDTI, but are connected to EDTI's distribution system with a primary operating voltage of 25,000 V (25 kV) or less. Requirements relevant to the safety, operation, performance, testing and maintenance of the interconnection are provided.

The requirements established in this document cover a broad spectrum of interests. The addition of DERs to the distribution system may change the system and its response. Attaining a technically sound, strong and safe interconnection between DERs and the distribution system mandates diligence on the part of everyone involved in the interconnection. The requirements in this guideline need to be cooperatively understood and met by everyone involved in the interconnection, including designers, manufacturers, users, owners and operators of both DERs and distribution systems.

This guideline has been developed with reference to national and international standards such as Canadian Standards Association (CSA) C22.3 No. 9-08, Interconnection of Distributed Resources and Electricity Supply Systems, and the Institute of Electrical and Electronic Engineers (IEEE) standard 1547, Standard for Interconnecting Distributed Resources with Electric Power Systems.

This document does not constitute a design handbook. Distributed energy resource providers (DERPs) who are considering the development of a DER facility intended for connection to EDTI's distribution system should engage the services of a professional engineer or a registered consulting firm qualified to provide design and consulting services for electrical interconnection facilities.

For inquiries relating to the connection of DERs, please contact EDTI Customer Engineering Services at

1 Alberta Electric System Operator (AESO) Distributed Energy Resources Policy Recommendations


The criteria and requirements in this document are applicable to all distributed energy resource technologies and to the primary and secondary voltages of EDTI's distribution systems. Installation of DERs on radial primary and secondary distribution systems is the main emphasis of this guideline (restrictions relating to EDTI's downtown secondary network distribution system are described in section 1.3.8). The requirements in this document shall be met at the point of common coupling, although the location of the protective devices may not necessarily be at that point.

This interconnection guideline is a minimum requirement for the interconnection of DERs. Additional requirements may have to be met by both the DERP and EDTI to ensure that the final interconnection design meets all local, national and international standards and codes, and is safe for the application intended.

This guideline does not address any liability provisions agreed to elsewhere by both parties in a commercial agreement or tariff terms and conditions.