Insight: Why Hurricane Ida crippled the New Orleans power grid

ICF International

04/09/2021 12:00

By Tim McLaughlin and Stephanie Kelly
    Sept 4 (Reuters) - Hurricane Ida's 150-mph winds crippled a
Louisiana electric grid already vulnerable from aging
transmission lines, electricity bottlenecks and $2 billion worth
of damage caused by three hurricanes that hit last year.
    Ida’s landfall on Sunday left a wake of destruction and
suffering. More than 1 million customers were without
electricity immediately after the storm - a hardship that, for
some, could last weeks.
    Entergy Corp  ETR.N , the largest Louisiana utility, is
facing tough questions on whether it had done enough to harden
the electric system, which lost eight major transmission lines
delivering power to the New Orleans metropolitan area.
    Entergy was in the midst of upgrades throughout its system
after Hurricane Laura in 2020. From 2017 to 2019, Entergy's
Louisiana subsidiary spent about $1.2 billion on numerous
projects to improve its transmission system.
    A pivotal question now for Entergy and its consumers is how
well those capital improvements survived the hurricane’s wrath
compared to the company's older infrastructure. Entergy declined
to detail the age of the eight New Orleans-area transmission
lines that failed.
    “The reason the lights are out is not because we aren’t
building a resilient system,” said Rod West, Entergy’s group
president of utility operations. “The lights are out because
Mother Nature is still the undisputed, undefeated heavyweight
champion of the world."
    Hurricane Laura in southwest Louisiana highlighted how
Entergy operates a transmission network with two different
design standards for resisting wind damage. Transmission lines
and infrastructure built in recent years are rated to withstand
140-mph winds, and in some cases up to 150 mph gusts, according
to Entergy disclosures with Louisiana utility regulators.
    But large sections of Entergy’s Louisiana network were
designed to withstand wind speeds far below what Ida delivered.
About one-sixth of Entergy Louisiana's transmission system,
covering about 900 miles, consists of 69-kilovolt lines, the
majority of which are only rated at 95 mph, according to Entergy
disclosures to regulators.
    The 1970s-era design standard, which was used in building
part of the network that feeds New Orleans, is a holdover from
when Gulf States Utilities operated the transmission system,
according to Entergy disclosures to Louisiana regulators. 
    Many structures on the legacy system were destroyed last
year during Hurricane Laura, according to testimony submitted by
Entergy executives this year to the Louisiana Public Service
Commission. The company has asked regulators to approve more
than $500 million to repair and rebuild damaged transmission
lines from 2020 hurricanes, a cost that would be shouldered by
ratepayers in their monthly electric bills.
    Three years after Entergy merged with 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 older, lower standard because they
complied with NESC codes at the time they were constructed.
    That leaves the network more vulnerable to outages, said
Praveen Malhotra, an engineer and expert on catastrophe risk who
has studied hurricane effects on transmission systems.
    “The whole system is only as strong as the weakest link,”
Malhotra said. 
    Entergy said in a statement that much of the damage from Ida
was related to the high winds, causing several lines to become
detached from their structures. The eight transmission tie lines
that were rendered inoperable are vital because they connect the
integrated transmission system in the greater New Orleans area
to the larger national grid.
    
    MORE POWERFUL STORMS
    Just weeks before Ida hit, Entergy and construction firm
Burns & McDonnell began rolling out helicopters and swamp
equipment to rebuild and upgrade an old 16-mile transmission
line that delivers electricity from the Waterford 3 nuclear
reactor in Killona, La. to a substation on the outskirts of New
Orleans. As of Friday, the transmission line was disconnected
from the grid and the Waterford plant was listed as producing no
power, according to the U.S. Nuclear Regulatory Commission
website. 
    It’s the second time in a year the $52 million transmission
line upgrade has been foiled by a hurricane. When Hurricane
Laura hit in August 2020, Entergy and Burns & McDonnell pulled
crews off the upgrade job so they could work on restoring power
to more than 200 transmission lines damaged by the storm. They
also moved transmission towers slated for the Waterford line to
areas damaged by Laura, according to a July 13 Burns & McDonnell
news release touting the re-start of the project upgrade. 
    When Ida made landfall, Entergy was in the midst of spending
$86 million in Lafourche Parish, which includes Port Fourchon,
to rebuild a line originally constructed in 1964. That project
was due to be completed next year, according to Entergy’s
website. 
    Hurricane Laura, which hit the Lake Charles area in
southwest Louisiana, mostly damaged Entergy’s weaker legacy
infrastructure. Michelle Bourg, an Entergy vice president, said
in testimony submitted to the Louisiana Public Service
Commission in April that legacy systems were damaged or
destroyed by that storm while more modern work was "largely
unaffected" by Laura.
    The failures of older lines still left the city of Lake
Charles without power for 13 days. 
    Some customers affected by Ida could 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 beach community where most homes 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 about 823,000 on Friday, after Entergy said it
had restored service to about 225,000 customers. Entergy
estimated Friday that most communities should have power
restored by Sept. 8.
    In the wake of the destruction, utility companies are under
intense pressure and scrutiny to repair lines and infrastructure
quickly to avoid prolonged suffering by their residential and
business customers. 
    The company "is required to expend large sums very quickly,"
Entergy Louisiana LLC Chief Executive Phillip May said in recent
testimony to regulators, adding that the company has to also
worry about its liquidity and credit rating as it issues more
debt to fund restoration. 
    
    EXTREME STORM        
    The challenge for Entergy in the New Orleans area is
circumventing multiple bodies of water that limit the corridor
for more transmission lines that could take on power
distribution 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 meanders through the city.
    Logan Burke, executive director of nonprofit Alliance for
Affordable Energy in New Orleans, said Entergy is trying to
solve the city’s transmission problem by building more
generation capacity in the area. But the company is not doing
enough, she said, to relieve the electricity bottleneck leading
into greater New Orleans.
    New Orleans' dense population and surrounding bodies of
water provide a limited number of transmission line corridors.
Without sufficient capacity, the transmission lines cannot
deliver all the available power generated outside the city. Part
of Entergy's solution has been to build generation capacity that
is physically within the New Orleans area while rebuilding and
redesigning sections of the transmission network.
    Louisiana has access, through Entergy, to multiple nuclear
plants, said Eric Smith, associate director of the Tulane Energy
Institute, adding that New Orleans partially receives power from
a nuclear facility in Arkansas. "But if you can't get power to
the city then it doesn't matter."
    In the meantime, severe weather events are becoming more
frequent. Experts at ICF, a global consulting firm based in
Virginia, estimate that U.S. utilities will have to spend $500
billion to address vulnerabilities from more frequent and severe
weather patterns caused by climate change. ICF said in a recent
report that the U.S. experienced 119 billion-dollar disasters in
the 2010s, compared with 111 total from the previous two
decades. 
    That's a problem for companies still dealing with legacy
systems that date to the 1950s and 1960s.
    “My sense is this hurricane had extreme conditions even by
extreme hurricane standards," said Larry Gasteiger, executive
director of WIRES, a trade group that advocates for investment
in needed 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;
editing by David Gaffen and xxx)
 ((tim.mclaughlin@thomsonreuters.com; +1 617-856-4409; Reuters
Messaging: Tim.McLaughlin.thomsonreuters.com@reuters.net))