September 15, 2021
  • September 15, 2021

Why Hurricane Ida crippled New Orleans’ power grid

By on September 4, 2021 0

September 4 (Reuters) – 150 mph winds from Hurricane Ida crippled a Louisiana power grid already vulnerable to aging transmission lines, power bottlenecks and $ 2 billion in damage from three hurricanes that hit last year.

Ida’s landing on Sunday left a trail of destruction and suffering. More than a million customers were without power immediately after the storm – a ordeal that, for some, could last for weeks.

Entergy Corp (ETR.N), Louisiana’s largest utility, faces tough questions about whether it has done enough to harden the power system, which has lost eight major transmission lines feeding the metro area. of New Orleans.

Entergy was in the midst of system-wide upgrades following Hurricane Laura in 2020. From 2017 to 2019, the Entergy Louisiana subsidiary spent approximately $ 1.2 billion on numerous projects to improve its transmission system.

A critical question now for Entergy and its consumers is how well these capital improvements have survived the wrath of the hurricane compared to the company’s old infrastructure. Entergy declined to detail the age of the eight failed New Orleans transmission lines.

“The reason the lights are out isn’t because we’re not building a resilient system,” said Rod West, president of the Entergy group of utility operations. “The lights are out because Mother Nature is still the undisputed and undefeated heavyweight champion of the world.”

Hurricane Laura in southwest Louisiana showed how Entergy operates a transmission network with two different design standards to resist wind damage. Transmission lines and infrastructure built in recent years are designed to withstand winds of 140 mph and in some cases gusts of up to 150 mph, according to Entergy’s disclosures with utility regulators at the Louisiana.

But large sections of the Entergy system in Louisiana were designed to withstand wind speeds well below those provided by Ida. About one-sixth of Entergy’s transmission system in Louisiana, covering about 900 miles, consists of 69-kilovolt lines, the majority of which are only rated at 95 mph, according to Entergy’s disclosures to regulators.

The 1970s design standard, which was used to build part of the grid that powers New Orleans, is a holdover from when Gulf States Utilities operated the transmission system, Entergy discloses to regulators. of Louisiana.

Many structures in the legacy system were destroyed last year during Hurricane Laura, according to testimony submitted by Entergy executives this year to the Louisiana Civil Service Commission. The company has asked regulators to approve more than $ 500 million to repair and rebuild transmission lines damaged by the 2020 hurricanes, a cost that would be borne by taxpayers in their monthly electricity bills.

Three years after Entergy’s merger with the Gulf States in 1994, the company implemented a more robust design for the transmission network that met or exceeded the National Electrical Safety Code (NESC) standard. But the network still includes lines built to the old lower standard, as they met NESC codes at the time of construction.

This makes the network more vulnerable to outages, said Praveen Malhotra, an engineer and disaster risk expert who has studied the effects of hurricanes on transmission systems.

“The whole system is only as strong as the weakest link,” said Malhotra.

Entergy said in a statement that much of the damage Ida caused was related to high winds, causing several lines to detach from their structures. The eight transmission lines that have been rendered inoperative are vital as they connect the integrated transmission system of the greater New Orleans area to the larger national grid.

MORE POWERFUL STORMS

Just weeks before Ida’s coup, Entergy and construction company Burns & McDonnell began deploying helicopters and swamp gear to rebuild and upgrade an old 16-mile transmission line that provides power. electricity from the Waterford 3 nuclear reactor in Killona, ​​Louisiana, to a substation on the outskirts of New Orleans. The transmission line was disconnected from the grid on Friday and the Waterford plant was listed as not producing electricity, according to the website of the United States Nuclear Regulatory Commission.

This is the second time in a year that a $ 52 million transmission line upgrade has been foiled by a hurricane. When Hurricane Laura struck in August 2020, Entergy and Burns & McDonnell removed crews from upgrade work so they could work to restore power to more than 200 storm-damaged transmission lines. . They also moved transmission towers planned for the Waterford Line to areas damaged by Laura, according to a July 13 press release from Burns & McDonnell touting the restart of the project upgrade.

When Ida made landfall, Entergy was spending $ 86 million in the parish of Lafourche, which includes Port Fourchon, to rebuild a line originally built in 1964. This project was due to be completed next year, according to the website. from Entergy.

Hurricane Laura, which hit the Lake Charles area in southwest Louisiana, mainly damaged Entergy’s weaker legacy infrastructure. Michelle Bourg, vice president of Entergy, said in testimony submitted to the Louisiana Civil Service Commission in April that legacy systems had been damaged or destroyed by this storm while more modern work was “largely” unaffected “by Laura.

Old line outages left the town of Lake Charles without power for 13 days.

Some customers affected by Ida may be without power for a similar period or longer, particularly in outlying areas. When Ida struck, Jim King, 75, was one of the only people in Grand Isle, a small seaside community where most of the houses are built on stilts at least 15 feet high. He said he expects to be without power for months.

The total number of homes and businesses without power in the state fell to around 823,000 on Friday, after Entergy said it restored service to around 225,000 customers. Entergy estimated on Friday that most communities should have power restored by September 8.

In the wake of the destruction, utility companies are under intense pressure and scrutiny to quickly repair lines and infrastructure to avoid the prolonged suffering of their residential and commercial customers.

The company “is required to spend large sums of money very quickly,” Phillip May, managing director of Entergy Louisiana LLC, said in recent testimony to regulators, adding that the company must also be concerned about its liquidity and of its credit rating because it issues more debt to finance the restoration.

EXTREME STORM

The challenge for Entergy in the New Orleans area is to bypass several bodies of water that limit the corridor for more transmission lines that could take over the distribution of electricity in the wake of another powerful storm. Lake Pontchartrain is to the north; the Gulf of Mexico lies to the east; and the Mississippi River winds through the city.

Logan Burke, executive director of the nonprofit Alliance for Affordable Energy in New Orleans, said Entergy is trying to solve the city’s transmission problem by boosting generation capacity in the area. But the company isn’t doing enough, she said, to ease the electricity bottleneck to New Orleans.

New Orleans’ dense population and surrounding water bodies provide a limited number of transmission line corridors. Without sufficient capacity, transmission lines cannot supply all the available energy generated outside the city. Part of Entergy’s solution was to build generating capacity that is physically located in the New Orleans area while rebuilding and redesigning sections of the transportation network.

Louisiana has access, via Entergy, to several nuclear power plants, said Eric Smith, associate director of the Tulane Energy Institute, adding that New Orleans is partially supplied with power by a nuclear facility in Arkansas. “But if you can’t supply the city with electricity, it doesn’t matter.”

In the meantime, severe weather phenomena are more and more frequent. Experts from ICF, a global consulting firm based in Virginia, estimate that U.S. utilities will need to spend $ 500 billion to address vulnerabilities caused by more frequent and severe weather conditions caused by climate change. The ICF said in a recent report that the United States experienced $ 119 billion in disasters in the 2010s, up from a total of 111 in the previous two decades.

This is a problem for companies that still use legacy systems that date back to the 1950s and 1960s.

“I feel like this hurricane had extreme conditions, even by extreme hurricane standards,” said Larry Gasteiger, executive director of WIRES, a business group that advocates investment in the necessary transmission. “You may not be able to build a system that can withstand absolutely anything.”

Reporting by Tim McLaughlin and Stephanie Kelly; additional reporting by Devika Krishna Kumar in Grand Isle, Louisiana; edited by David Gaffen and xxx

Our standards: Thomson Reuters Trust Principles.


Source link