Weathering the storm - GMP's Zero Outage Initiative coming to Thetford

Thetford residents still remember the December storm of 2022 when heavy wet snow and ice brought down trees, power lines, and utility poles, blocking roads and confining people to their homes. The experience was epitomized in one resident's email "With the power outage for two days, and phone/internet out for three days, there was no way to get email messages ... or find out anything .... We were OK with a wood stove, but at least one set of elderly neighbors had no heat backup."

Green Mountain Power is trying to avoid a repeat of this scenario. The Town of Thetford recently received a message from Kevin Matte, GMP's Operations Supervisor. Kevin gave a heads-up that "GMP is proposing storm hardening the electric grid in your area" and that several large GMP projects are in the works for Thetford. GMP Distribution Designer Ryan Kreis will soon be contacting the Town about burying electrical power lines in the road right-of-way. "We have chosen some of the worst areas to repair, update and make very dependable."

This, of course, is not limited to Thetford, but is part of GMP's Zero Outage Initiative, a first-in-the-nation push to put in place "a comprehensive, data-driven plan that creates layers of resiliency across Vermont by building on GMP’s successful and proactive undergrounding and storm-hardening of lines, as well as deployment of energy storage through batteries and microgrids." The expectation is that this approach will lower overall costs while keeping communities and customers connected. 

The initiative was launched in October of 2023 following the devastating experience of the 2023 floods. GMP President Mari McClure declared, "We must move faster ... to  combat climate change and create a Vermont that is sustainable and affordable." 

 It won't be cheap; for the first leg of the initiative GMP asked regulators for an investment of up to $280 million to cover 2024-2025. Out of that, $250 million is going toward burying lines or "storm-hardening" them, and  $30 million is going toward energy storage. The second leg will need another infusion of funding from regulators to speed up and expand the effort beyond 2026. It is anticipated that repair costs for power outages will have started to decrease by then. 

While it seems a lot, keep in mind that from 2013-2023 major storms resulted in $115 million in damage across GMP's service area, with the last two years incurring 40% of those costs. The year of October 2022- October 2023 brought the three worst storms in the history of GMP and the most expensive yet, at $45 million in repairs. Those repairs only restored the status quo and did nothing to prevent future outages.

Research shows that investments in disaster preparedness and mitigation pay for themselves several-fold in reduced repair and recovery costs. They also decrease the exposure of both repair workers and residents to unsafe conditions and health hazards. Electric line workers are often required to work during storms or in the aftermath and to work quickly. They risk electrocution from downed power lines, falls on slippery surfaces, hits from falling debris, exposure to extreme cold and high wind gusts while climbing poles, and poor visibility in debris-filled areas. 

The majority of outages are caused by fallen trees and branches. Thus for most communities GMP will  "harden" major feeder lines from electric substations by making them very strong and well-insulated. In more remote areas, electric lines serving small numbers of customers will be buried, as proposed for Thetford. 

GMP has installed over 50 miles of underground lines. It is also incorporating energy storage. Customers in remote areas would be provided with batteries, with the eventual goal of energy storage for all customers. Indeed VT regulators have relaxed the enrollment restriction for home battery programs, allowing all interested customers to sign up for cost-effective home batteries. 

There are also more advanced approaches under the Zero Outages Initiative, based on two things. One is "circuit-level grid resiliency" which involves analysing the power grid in terms of smaller individual circuits that make up the grid, and redesigning and operating them as units to minimize outages and allow rapid restoration of power. GMP's grid contains 300 such circuits. This can be combined with information on an area's community / social vulnerability data, such as poverty, lack of transportation, and crowded housing, that are obtained from the Centers for Disease Control (CDC) to evaluate the needs of each circuit.

Based on social vulnerability data, GMP is establishing Resiliency Zones equipped with solar panels and the all-important storage batteries. These projects are taking place in Brattleboro, Grafton, and Rochester. The latter town was famously cut off completely from power and road access for many days following Tropical Storm Irene in 2011. 

The other innovation is the "microgrid." An example of a GMP microgrid now exists in Panton, VT. In a nutshell, it is a grid section that can disconnect from the larger grid and be self-sustaining by making and storing its own electricity. In Panton a large array of solar panels charges a bank of batteries that store 4,000 kilowatt-hours of electricity. That's enough to power eight homes for a month. When the grid experiences a power outage, the microgrid's computerized controls switch over seamlessly to batteries. At present it serves 55 customers and can expand to 900 or more. There are other examples, for instance a South Burlington neighborhood where a planned 155 homes are being equipped with rooftop solar plus storage batteries. They will also be linked to a community microgrid with utility scale batteries.

We've chosen to inhabit a beautiful place. However the scenic features we love, like steep river valleys, streams, and trees, make us very susceptible to the increasingly severe effects of climate change. While GMP's groundbreaking model of resilience may not hold up in an extended catastrophe, in most scenarios it will go a long way towards benefitting most Vermonters.