I don’t often get an email
from a colleague in Scotland asking how I’m weathering the power cuts in
Texas. But I did last Friday, after the
worst was over.
For much of last week,
millions of Texans had to endure the loss of electric power, and all that entails,
during some of the coldest weather on record.
Early Monday morning, Feb. 15,
the Electric Reliability Council of Texas (ERCOT), the nonprofit organization
that operates the Texas power grid, ran out of power. That is to say, the soaring demand due to
millions of heating units working overtime exceeded the dropping supply due to
equipment failures caused by the same cold weather. In order to avoid an uncontrolled system crash
that would take weeks to recover from, ERCOT commanded its grid customers
(operating companies that distribute the power and collect power bills) to
implement rolling blackouts, handing out percentages of their load they had to
shed. How they shed it was up to them,
but shed they must.
This put increasing numbers of
electric customers in the dark, both physically and informationally. Although many people could access news and websites
through their phones, there wasn’t that much to learn about how the power cuts
were being decided or how long they would last.
Here in San Marcos, our house had power all day Monday. That evening I
was on a Zoom conference with some people in Austin, who’d been told that the
rolling blackouts would last only an hour or so. Instead, it seemed that almost everybody in
Austin lost power and stayed in the dark except for a lucky few who happened to
be on a “critical feeder” that powered a hospital or fire station.
In the middle of the Zoom
call, our power went out. My laptop
battery kept my computer going, though, and I managed to power our modem and
wireless network with an emergency battery powerpack and inverter, and I got
online long enough to complete the call.
But then I went to bed at 8:30, as it was getting cold in the house. We had an hour or two of power every so often
for the next two days, but it was mostly off until Wednesday afternoon. Many people in Austin and other parts of
Central Texas fared much worse, losing power for two or three days straight,
and when their pipes froze they had to seek out an emergency shelter or stay
Like many engineering failures,
this one had multiple causes. On Friday,
the IEEE (Institute of Electrical and Electronics Engineers) Smart Grid Initiative
sponsored a webinar panel discussion on the crisis, and much of what follows is
taken from the information presented in that webinar.
As you may know, Texas has its
own power grid that operates independently of the grids in the rest of the
country. A “grid” is defined
by a region where all the power is synchronized to 60 Hz and can be fairly
easily shipped back and forth as the need arises. For historical reasons having to do with the
criticality of Texas infrastructure during World War II (and a bit of Texas
stubborn independence), most of Texas is covered by the grid supervised by
ERCOT. There are a few power interties
between Texas and other grids, but they require special equipment and cannot
provide significant amounts of power transfer.
So when an extraordinarily
cold air mass charged through Texas beginning on Sunday, ERCOT was going to
have to handle it by itself. On paper,
they were prepared. About half of the 80+
gigawatts (billions of watts, abbreviated GW) of nominal capacity for the grid
is natural-gas generation. ERCOT has
over 500 generating stations of various kinds to draw from, and some are more
reliable than others. Coal and nuclear
plants are the most reliable kind, but coal plants are being shut down these
days and no new nuclear plants are being built.
A quarter of Texas’ installed capacity is wind, but wind generators are
notoriously unreliable, and once the cold air arrived it stopped moving, idling
most of the wind turbines and freezing up many of them.
The usual alternative in such
a situation is to turn on gas-fired turbine generators, which in principle can
be started up in minutes to augment the grid’s energy sources. But the same weather that caused demand to
soar also crippled the natural-gas infrastructure, freezing well heads and
control valves and causing other problems that eventually eliminated some 26 GW
of gas-fired generators that could have otherwise been used. Although at the peak of the crisis, the grid
was producing some 62 GW of power, ERCOT would have had to come up with another
10 GW to meet the extraordinary demand produced by single-digit temperatures in
Houston and other normally balmy parts of central Texas. Hence the rolling blackouts that quit rolling
and just sat there until pipes froze and people had to seek warmer shelter.
How could this have been avoided? The panel experts proposed a number of
One was much better
interconnections to other grids, both from Texas to other grids and across
North America. This is an expensive
long-term solution, costing many billions of dollars over many years, and it
would increase the robustness of electric power nationwide. But as one expert pointed out, the grid
covering much of the Midwest, just north of ERCOT’s grid, was experiencing its
own rolling blackouts of less severity, and had no power to spare. So even if Texas had not been electrically
independent, we still would have had blackouts, but perhaps not as severe.
Another idea that has been
widely adopted in places like Italy is “demand response.” This is a smart-grid technology that allows
the power company to adjust the demand from individual consumers. For example, in exchange for a discount on
your power bill, you might allow your electric utility the right to reduce your
thermostat setting or cut off your electric dryer in power emergencies such as
the one Texas just experienced. If demand
response had been tested and widely deployed in Texas, the blackouts might have
been less severe, but they would probably still have been needed.
Fortunately, there were not
many fatalities directly attributable to the power outages, and so as crises go,
this one was greatly inconvenient but not deadly. Better enforcement of winterization protection
for natural-gas plants is the most urgent thing to do that will keep something
like this from happening again, but the final call is up to Mother Nature.
webinar called “The Texas Energy Crisis” available to IEEE members
and hosted by Peter Wung, IEEE Smart Grid chair, is the source of much of the
information in this blog. A more
politically oriented report that gets the technical matters mostly right was
written by Texan Kevin Williamson and was posted on the National Review
website at https://www.nationalreview.com/2021/02/understanding-the-texas-blackouts/.