Fallen trees are the leading cause of electrical outages during storms.

A Holistic Approach to Storm Planning and Restoration

Oct. 20, 2021
Unitil perpetually fine-tunes its best practices on storm preparedness and restoration as it cultivates a holistic path toward electrical resilience.

In the world of storm preparation and restoration, 365 days a year are spent preparing for the one day a storm hits. It is in these moments — when a tree falls or a power failure occurs — utilities must rely on years of planning, preparation and training to put an action plan together to restore power and minimize disruptions for customers. At Unitil Corp., a holistic approach to storm preparedness is central to its mission to deliver energy safely and reliably to customers. By approaching a significant weather event from all angles before, during and after, Unitil ensures a more resilient electrical system for those it serves.

There are two key pieces of storm preparedness and restoration:

  • The first aspect is preparing and responding to specific storms and emergencies. This includes immediate, short-term advance planning for predicted weather events
    and the use of well-established internal procedures and guidelines for managing restoration efforts, if necessary. In these instances, Unitil is guided by the nationally lauded, comprehensive emergency response framework known as the incident command system (ICS).
  • The second aspect is taking year-round proactive measures to mitigate damage caused by storms.This process has evolved through the execution of routine training and biannual drills (both gas and electric) that present realistic scenarios for employees to address as a team. Additionally, Unitil has created a storm resiliency program (SRP) to help reduce tree-related incidents, customer interruptions and impacts on municipalities along critical portions of targeted lines caused by major weather events — before they occur.

When it comes to storm planning and outage management, a utility is only as good as its last storm response. Through careful planning, drills and continuous improvements, Unitil perpetually fine-tunes its best practices and works to cultivate a holistic path toward electrical resilience.

Early ICS Adopter

Unitil was an early adopter of the ICS, a comprehensive emergency response framework that addresses potential incidents resulting from storms or other natural disasters, electric or gas system incidents, and civil emergencies not related to utility operations. The electric utility guide for ICS was a joint effort by members of the Edison Electric Institute (EEI), American Public Power Association (APPA) and National Rural Electric Cooperative Association (NRECA), which represent a large majority of the U.S.’s electric utilities (investor owned, public and cooperatives).

Adopted by Unitil in 2010, the ICS is a flexible framework that enables organizations to scale their response based on the severity and complexity of an incident. When activating the ICS, a utility’s response is coordinated from the top down in a centralized structure, headed by an incident commander. This organizational structure allows for absolute clarity as to who the decision makers are in any given situation, so response teams receive clear, consistent direction on an operational level. This framework enables Unitil to adapt or escalate its response to any size event or resource requirement.

From a public-facing perspective, the ICS manages communications to create a single source of information — tightly funneled from the incident commander outward — for accurate, consistent and timely communication to all stakeholders. Accurate information from a trusted source is critical during electric and gas emergencies, both from an operational and logistical standpoint and to mitigate public worry and confusion. Unitil’s two-way, top-down communication allows all parties to service stakeholders more effectively.

Employees are trained throughout the year in a secondary emergency role that activates during an incident. For example, in the event of an electrical emergency, gas employees are redeployed to serve as wire-down guards to protect the public. Depth also is a critical part of the ICS woven into the organizational structure; every role has a backup, ensuring preparedness under any circumstance.

The Same Language

Emergencies require utilities to work closely with municipal first responders. Because of its efficacy, the ICS organizational structure has been adopted by the Federal Emergency Management Agency (FEMA), National Park Service and U.S Department of Health and Human Services among other agencies as well as first-responder organizations across the country. By speaking the same structural language as first responders, utilities like Unitil can communicate seamlessly and work more efficiently in emergency situations.

To help community leaders prepare for an extended outage or upcoming weather event, Unitil proactively communicates safety- and emergency-related information and provides town- or region-specific information to municipal contacts to assist in emergency response planning and preparation. Under the ICS, multiple agencies can work in conjunction with one another following a single, comprehensive plan that is scalable and flexible.

Additionally, Unitil provides materials like zone maps, critical infrastructure listings, municipal forms, and other safety and procedural information to maintain communication and strategic partnerships with municipal leaders during emergencies or periods with extended outages. The utility also holds twice-a-day conference calls with municipal leaders, so they can receive real-time updates and provide concerns or issues to ensure an effective use of resources and community-wide response.

At the inception of the ICS, the EEI, APPA and NRECA aimed to develop a single guidance document for electric utilities to use when implementing various aspects of the system into their own unique response organizations. The intent was to further promote adoption of the national incident management system (NIMS) within the utility industry and enhance mutual-aid protocols by providing common terminology, hierarchy and standard-response procedures suitable for
any type of emergency.

As an early adopter of ICS, Unitil participated in this initiative to assist other electric utilities by providing feedback and content for the guidance document based on lessons learned throughout many previous storm responses. The initiative took more than two years of meetings — slowed by COVID-19 — but it should empower utilities not yet using the ICS to implement aspects of it.

Proactive Thinking

In the spirit of a truly holistic approach to storm preparation and restoration, Unitil takes preventive measures year-round to help ease the impact to customers come storm time. Fallen trees are the leading cause of electrical outages during storms. SRP is a proprietary vegetation management system developed by Unitil and oriented around the proactive prevention of electrical outages caused by fallen trees. To put it into perspective, routine tree pruning is intended to protect against regular New England weather conditions, such as snow, heavy winds and thunderstorms. The SRP helps to mitigate the damage caused by blizzards, tropical storms and other atypical weather events.

The SRP identifies key corridors, circuits and lines bringing electricity to critical infrastructures (for example, hospitals, gas stations and schools, which often are used as emergency shelters) that are at risk for service interruption during a storm because of surrounding trees. Working closely with communities, tree wardens and homeowners, Unitil methodically goes property by property to identify trees at risk of falling and causing a greater outage. Most of the trees the utility removes are dead, dying, defective or diseased and likely would not survive harsh weather conditions. To remain environmentally friendly, the SRP also involves replanting new trees in lower risk areas.

The process involves direct conversations with property owners, educating them about the benefits of the program. Customers receive several cost benefits because of the SRP. Ultimately, the cost for a utility to manage an outage — which is dependent on the time it takes, the number of crews and the equipment needed to restore power — is reflected in customer rates. By proactively reducing the number of trees that could cause electrical outages during a weather emergency, the SRP can help to mitigate the restoration cost for customers. Therefore, in addition to the inherent customer benefits of having a more resilient, reliable electrical system with shorter or no outages, customers also experience greater long-term affordability of service.

An electric system has a personality. Utility personnel who operate the system know what to expect based on the weather forecast and where the weak areas in its system are. Unitil has found that, because of the efficacy of the SRP, the personality of its system is changing. In regions where the SRP has been implemented, the system has grown far more resilient.

Unitil is in the final year of its 10-year SRP program. However, because of its success, the utility plans to continue expanding the program.

Continuous Improvement

The systems Unitil has in place are perpetually scrutinized and improved to become as efficient as possible. Because each storm is unique, it presents an opportunity to learn new things that can be incorporate into best practices — whether it stems from a customer question, logistical problem or something else. Unitil frequently participates in tabletop discussions and after-action reports to debrief storm responses and exercises to continually improve Unitil’s emergency response plan, which guides its response to major electrical threats and interruptions.

The COVID-19 pandemic caused the utility industry, along with most industries, to engage in creative problem solving and adjustments that would work in a socially distanced world. Each region Unitil serves has an emergency operations center (EOC) staffed with personnel who closely coordinate to develop response plans and manage response operations. With COVID, Unitil had to pivot that plan to identify which team members needed to physically report to the EOC and who could perform their role remotely. The utility found this was a beneficial exercise for future storm planning because it demonstrated more employees could remain in the safety of their homes during harsh weather events, when possible.

Unitil also continues to develop its technology stack. After a storm, assessors are dispatched to survey damage made to the electrical system. Traditionally, they are equipped with a notepad and map. After a full day of assessing damage, their handwritten data is returned and compiled to make a full report. To improve this process, Unitil will be deploying technology so damage assessors can go into the field with tablets or smartphones to better improve situational awareness and aid response planning. Once live, this application will improve restoration times by providing real-time damage assessment from the field and allow for improved decision making on resource allocation.

Implementing ADMS

Energy systems are continually evolving, and utilities should be adjusting their best practices based not only on what happened in the past but what will happen in the future. The need for electricity continues to grow. Today, humans manage and control the electric system — from power flow to voltage on the system — to ensure it is running optimally. All of this will change with grid modernization and distributed generation, fundamentally shifting the structure of the grid from a one-way power flow to multidirectional power generation.

Distributed generation will make the system much more complex, and there is still a lot of learning to do about what that means. Unitil is currently implementing an advanced distribution management system (ADMS) that will make the system more autonomous. The ADMS will allow for software with lots of sensors in the field, providing data on how to optimize voltage and save money for customers — all while making the system more efficient and effective.

During a storm event, the ADMS will restore customers automatically. The sensors will be able to locate and isolate what failed in the field — whether it be a tree that hit a wire or a piece of equipment that failed. Unitil will be able to sectionalize repair to ensure the least amount of people are affected. With the ADMS, the utility will eventually get to a point where it knows a customer’s lights are off and can dispatch a repair crew before the customer calls.

These constant technological advancements are a reminder of how critical it is to have a holistic approach to storm preparation and response. As the industry continues to learn and adapt, Unitil continues to prioritize creating a more resilient response to energy incidents during storms and events.

Editor’s Note: For a more in-depth article on the SRP proprietary vegetation management system, see the July 2021 issue of T&D World: Unitil Ramps Up Reliability.” 

Ray Letourneau is vice president of electric operations at Unitil, where he has worked since 1996. He is responsible for the utility’s electric field operations and labor relations. Letourneau has BSEE degree from Clarkson University, an MBA degree from Southern New Hampshire University and a certificate in electric power systems engineering from Power Technologies Inc. He also is a 2003 graduate of Leadership Seacoast and a former member of its board of trustees.

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