Utilities prepare for rolling blackouts
As winter officially begins Tuesday, concerns have been growing in New England about the impact a particularly cold season could have on the regional grid system, and the potential for a rare rolling blackout.
While Gordon van Welie, ISO-New England’s president and chief executive officer, downplayed the potential need for a rolling blackout as a “low probability event,” it was still presented as a worst-case scenario during a media briefing this month. For that to happen, officials said, there would need to be an extended period of cold weather combined with a lack of available natural or liquid gas to fuel the power plants.
The reason for the change can be found in recent history, according to Peter Brandien, ISO-NE’s vice president, system operations and market administration.
“Texas changed everything,” Brandien said, referring to the 17-day period last February when Texas was plunged into bitter cold and darkness because a massive failure of the power generation and electric. “We know we’re operating close to the edge. This problem is not going to go away and it’s going to gradually get worse.”
The closest New England has come to needing a rolling blackout in recent memory was a two-week stretch of historically cold weather that began on the day after Christmas 2017 and ended Jan. 8, 2018.
During that period, New England’s major cities had average temperatures below normal for at least 13 consecutive days, including 10 days when the temperature was more than 10 degrees below normal.
The region was also hit with multiple snowstorms, which complicated the delivery of oil — the second-most widely used fuel for power plants — into the region. With oil inventories low, and replenishment timelines unknown due to the storm conditions, ISO-NE officials took the unprecedented step of postponing the operations of oil-fired plants for later in the day or week and using other generating resources instead as a means of conserving fuel, Brandien said in April 2018.
So what exactly is a rolling blackout and what happens if one is required? Hearst Connecticut Media interviewed officials with ISO-NE and Connecticut’s two largest electric distribution companies to provide some of those answers.
What is the purpose of a rolling blackout?
“Controlled power outages are needed when there is not enough electricity to meet consumer demand and system operators have exhausted all other options to re-calibrate the balance of supply and demand,” said Matthew Kakley, an ISONE spokesperson. “This could be caused by a number of different things, including unexpectedly high demand or the sudden, unexpected loss of generators or transmission lines.”
Kakley said the grid operators particular concerns this winter are that generators will not have adequate fuel to operate during a prolonged period of very cold weather.
What is a “controlled outage?”
Officials with ISO-NE and the electric distribution companies are careful to differentiate between a controlled outage, which is often used interchangeably with “a rolling blackout,” or “load-shedding,” and a fullscale blackout.
A controlled outage is an event in which regional electric grid operators and electric distribution companies deliberately shut down power to a portion of their customers for a specific period of time to protect the integrity of the grid. A full-scale blackout occurs when weather conditions or a system failure renders the generation and electricity delivery system inoperable across a widespread area.
“Implementing controlled power outages would be a last resort to prevent a complete collapse of the region’s power system, which would take days or weeks to repair,” Kakley said. “By reducing demand in a controlled manner, system operators are able to restore that demand safely once the underlying problem is resolved. Uncontrolled outages can cause damage to grid infrastructure, which must then be physically repaired before power can be restored.”
The largest example of a full-scale blackout in North America occurred on Aug. 14, 2003 when a high voltage power line in Ohio came in contact with overgrown trees and set off a cascading shutdown of regional power grids that spread across eight states and left 50 million people without power for up to two days. The event contributed to at least 11 deaths and cost an estimated $6 billion.
Who decides a rolling blackout is needed?
Gage Frank, a spokesperson for United Illuminating, said ISO-New England makes that determination and will instruct utility companies to begin taking measures to balance the supply and demand. UI serves 17 communities, including New Haven and Bridgeport as well as surrounding municipalities.
“Depending on the situation, a controlled outage event would be first initiated only after less impactful measures have been taken,” Frank said. “For example, ISO-NE and the utilities calling for customers to reduce their energy use.”
Kakley said another option ISO-NE can use before calling for a controlled outage event also includes importing emergency power from other regions and from Canada.
How much advance notice will utility customers get before a rolling blackout?
Brandien said weather forecasts and conditions will allow the grid operator enough time to give consumers advance notice of the need for a rolling blackout.
“If we have enough time, we want to educate consumers that we’re going to need conservation (of power) to head that off,” he said. “The more conservation that we get. the less extreme actions we're going to have to take. We're going to ask consumers to use the same sort of measures they would during a hot summer day.”
UI’s Frank said the utility will provide “large-scale and localized messaging to customers, members of the press and state and local officials.”
“UI customers are encouraged to follow our social media accounts for additional updates,” he said.
Modifica said “if an energy emergency would require rotating outages over several days, we would provide affected customers with as much advance notice as possible.”