Mid term project

2021 Texas Power Outages:

Facts and Initial Thoughts

Hao Zhu

Assistant Professor

Department of ECE

The University of Texas at Austin

Acknowledgements: Dr. Ross Baldick, Power-Globe Discussions

February 22, 2021

Winter Storm 02/13-17

➢ Record long freezing temperature and level of snowfall

➢ >4.5 million Texas homes and business without power during the peak outage time

➢ Water outages and quality issues

➢ Gas shortages and price spikes

➢ State of emergency declared

2

Outage map on 10-11am, 02/16 TexasTribune

Pre-storm timeline

➢ 02/08-02/11: ERCOT issued Notice, Advisory, and Watch for the expected extreme cold weather on 02/11-02/16

➢ 02/11: ERCOT announced expecting record electric use due to extreme cold weather; predicted peak demand at Monday (02/15) morning

▪ “Generators have been asked to take necessary steps to prepare their facilities for the expected cold weather, which includes reviewing fuel supplies and planned outages and implementing winter weatherization procedures.”

➢ 02/11: Electric utilities experienced local circuit outages

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02/1402/08 02/10 02/11

Post-storm timeline

➢ 02/14: ERCOT requested energy conservation 02/14-02/16

6-7pm: set winter peak demand at 69,150 MW (summer peak 74,820 MW)

➢ 02/15: entered Energy Emergency Alert (EEA) at midnight (00:17)

01:25: EEA3, rotating outages, “10,500 MW load shed... Extreme weather conditions caused many generating units – across fuel types – to trip offline and become unavailable... ~34,000 MW of generation forced off the system”

➢ 02/18: majority of customers restored

➢ 02/19: ended emergency conditions

4

02/1902/14 02/15 02/18

5

➢ Why winter peak? Half

of Texas homes use

electricity for heating

➢ Projected peak of 75GW

in the morning of 02/15

➢ Actual demand 44 GW

due to controlled

outages

Viewing it as a car

➢ Peak demand = climb a hill

➢ Offline generation = two out of four tires

flat, or losing half of the horsepower

▪ 34 GW out of 75 GW

➢ We keep one backup tire that can

temporally relieve an emergency

➢ But unable to handle two flat tires

➢ Especially if the backup tire is also flat

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Why generation offline?

➢ Generation plants not prepared for extreme cold

weather (lowest temp. below 0F)

➢ Gas supply (frozen pipelines and other priorities)

➢ Thermal (coal, gas) plants: 28GW ~37% capacity

▪ Nuclear: 1.3GW at South Texas Nuclear Power

➢ Renewable wind & solar: 18GW (26GW total)

▪ However, only 10GW in ERCOT winter peak planning

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[Financial Times, NY Times]

http://www.ercot.com/content/wcm/lists/197391/ERCOT_Fact_Sheet_3.20.20.pdf

https://t.co/KNtbWIyzKz?amp=1

http://www.ercot.com/content/wcm/lists/197378/SARA-FinalWinter2020-2021.pdf

A closer look

➢ ~50% ERCOT capacity/ energy from natural gas

➢ ERCOT planned for 85GW peak capacity in winter

▪ 87% thermal (~76GW)

▪ 9.7% wind (9.3GW)

▪ 1% solar (0.7GW)

➢ Expected low renewable outputs and 100% thermal availability in winter

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Gas ↓ 15GW

Coal ↓ 3GW

Nuclear ↓ 1GW

Wind ↓ 4GW

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https://www.eia.gov/beta/electricity/gridmonitor/dashboard/electric_overview/regional/REG-TEX

ERCOT to be blamed?

➢ ERCOT is a system operator: balance supply- demand and control the flow of electricity

▪ Covers 90% of Texan electric load; 75% of land

▪ > 46,500 miles of transmission lines

➢ ERCOT doesn’t own the generation units

▪ Cannot mandate generation to weatherize

➢ Successfully handled the 69GW peak demand on 02/14, no reported transmission issues

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[Synthetic ERCOT grid, TAMU]

What about electricity market?

➢ Wholesale prices -> $9k/MWh (price cap)

▪ 300 times of the normal rate $30/MWh

➢ Scarcity market: aiming to incentivize generators to self-invest in emergency mitigation solutions

➢ Some believe a capacity market is better, but unlikely to cope with 1/3 loss

▪ back to the car example, it is like paying for some generators to be the backup tire

➢ Market economics may fall short of incentivizing long-term investment!

11

Hogan, William. "Electricity scarcity pricing

through operating reserves: An ERCOT window

of opportunity." Harvard University. Cambridge

(MA) (2012).

www.spglobal.com

Interconnection is better?

12

➢ Many blame an independent Texas grid from Texas pride & independence tradition in general

➢ ERCOT formed in 1970 as an ISO

▪ comply with NERC (NA Electric Reliability Corp.) requirements

▪ not subject to FERC (fed energy regulator)

➢ Encourages efficiency/reliability, yet costly and vulnerable to external failures (domino effects)

▪ 2003 US/Canada Northeast blackout

▪ 2011 Southwest blackout

https://www.texastribune.org/2011/02/08/texplainer-why-does-texas-have-its-own-power-grid/

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Demand

exceeds

supply

Supply

maxed

out

~4-6GW

reserve

Demand

exceeds

supply

All our neighbors (hit by same storm) were almost maxed out, if not under- supply

[IEEE Smart Grid Webinar, 02/19/21]

ERCOT is connected to East/Mexico

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[ERCOT DC-Ties Operations, 2014]

➢ HVDC tie-lines ~1100MW

➢ Import (in neg. values) declined as our neighbors maxed out

But wait, what about fed regulations?

➢ US Congress only authorized FERC to do annual or seasonal assessments on generation adequacy.

▪ Like the ERCOT winter planning table earlier

➢ NERC requires N-1 reliability (losing one line/ unit), far from enough for this event

▪ ERCOT is actually better than N-1, capable to cover the outages of 2 nuclear plants (~4GW)

➢ Each state regulator, public utility commission (PUC) Texas in our case, determines other types of generation adequacy assessments

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[FERC Planning Resource Adequacy Assessment Reliability Standard, 02/18/21]

Looking back at 2011 Texas Blackout

➢ 02/02/2011, extreme cold led to a spike in electricity use, and coal/natural gas plants and electric utilities couldn’t maintain service.

➢ Rolling blackouts across the state, from 20 minutes to over eight hours.

▪ “Generators were generally reactive as opposed to being proactive in their approach to winterization and preparedness. The single largest problem during the cold weather event was the freezing of instrumentation and equipment.”

▪ “Balancing authorities, Reliability Coordinators, Transmission Operators and Generation Owner/Operators in ERCOT … should consider preparation for the winter season as critical as preparation for the summer peak season.”

➢ Not aware of any states having this type of regulation

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FERC/NERC “Outages and Curtailments During the Southwest Cold Weather Event of February 1–5, 2011

Why system-wide failure?

➢ Immediate cause is the extreme cold weather

➢ Fundamentally, power grids, like most other civilian infrastructure, are designed to withstand random, local, small-scale failures

▪ cars, airplanes, buildings, transportation/water/gas networks

▪ based on cost-benefit analysis using a stochastic risk

➢ But overlooking factors of global impact can cause catastrophic outcomes

▪ Common-mode failures, or high-impact low-frequency (HILF) events

▪ Natural disasters: winter storms, hurricanes, earthquakes, solar storms, wildfires

▪ Malicious compromises: cyber attacks, EMP attacks

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How to future proof?

➢ Enhancing resilience against extreme weather disasters

▪ we have witnessed more frequent occurrence of natural disasters

▪ proactively studying for these events, using more updated data/analysis

▪ designing systems with emergency controls in mind

▪ hardening the grid infrastructure (G/T/D) and across systems (gas/water)

➢ System-wide actions for ERCOT

▪ changing climate scenarios studies

▪ gas-electricity coupling

▪ weather-aware capacity model

▪ energy storage or flexible resources

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Modernizing the local utility systems

➢ Sectionalizing circuits for flexible network configuration

▪ Austin Energy had to put ALL non- critical circuits without power for days

▪ Many commercial/residential users on critical circuits (with government, hospitals, ect.) were not impacted

▪ Could have implemented a rolling blackout among all non-critical users

➢ Automatic load control, aka demand response programs

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[ucsusa]

Hao Zhu [email protected]

http://sites.utexas.edu/haozhu/ @HaoZhu6

Thank you!

“It may appear that we are going in circles but,

at least, the circles are moving forward.”

- A PJM Committee Member

Indirectly from Ron Chu