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Project: T184700 #50/149

Distributed Energy Resources (DERs) are being installed at an accelerated rate, and utility concerns are rising as to the safety impact of this new technology. Multiple sources of energy that are not directly controlled by the utility and power from unusual sources are among these new concerns. The objective of this project is to identify effective practices for maintaining an acceptable level of worker safety in the presence of DER connected to the distribution grid. The research documents several existing codes, rules, standards, acts, and regulations on worker safety across jurisdictions in Canada and the United States. To study experts’ interests and concerns on the topic, volunteer utilities were interviewed. The areas of concern are typically technical question of what conditions may impact worker safety. Safety practices such as isolation, grounding, hold offs (a device to block automatic reclosing or manual re-energization of a line or equipment after an automatic trip), visible break, and lockout/tagout are reviewed to study the effectiveness of offering worker protection in the presence of DER. A review of risks in various scenarios such as normal operating conditions, normal operating conditions with DER, emergency restoration operating scenarios, abnormal conditions within the DER facility, DER facilities that operate in an intermittent fashion, and DER facilities that are connected to the grid without the utility’s knowledge are presented. Finally, the conclusions are crafted based on the findings of a review of risks and recommendations to the utilities are provided.


Distributed Energy Resources, Safe Work Zone, Isolation, Grounding, Visible Break, Lockout/Tagout, Hold offs