Texas: Energy Powerhouse vs. Severe Winter Storm


A guest article by Tom Murphy, Director, Penn State Marcellus Center for Outreach and Research.

During the week of February 15th, an intense winter snow and ice storm hit some parts of northern Mexico and the southwestern U.S. region, with particularly cold air for much of the week. Although this region on occasion receives blasts of cold winter weather, this storm impacted 29 million Texan residents with an onslaught of conditions which took much of the power grid offline, and at the same time, impacted other components of the energy infrastructure in a manner which strained capacities in a similar way that a summer heatwave might. The main difference was the very cold conditions froze many components of the energy systems which normally would run closer to their designed peak loads. 

There are, and will continue to be, many legislative and regulatory inquiries as to its cause and how to prevent a similar future mishap.  But early forensic and engineering analysis has identified three main areas of deficiency:
 
Frozen Systems

The reality on the ground is that much of the energy infrastructure in Texas is not constructed to account for extreme winter weather and literally froze due to cold pipes.  This included upstream fuel supply, with approximately 20% of natural gas wells temporarily offline in the state due to formation of hydrates.  One of the four nuclear reactor units in the state suffered the same fate due to cold, as it went offline for a brief time.  And, amid the coldest extended weather seen in decades, wind turbines in numerous regions of the state also were not able to function due to ice build up on their large blades – this was compounded by low wind speeds at the time.

All of this contributed to a significant drop in power generation capacity and natural gas deliveries when demand for both was quickly rising.  Similar energy infrastructure in regions of North America which normally have colder winters have fail-stop systems in place to prevent this type of calamity. Now, with the weather back to normal and the power and gas grids meeting demand, attention has turned to preventing this in the future with concerns of climate impacting new energy policy directives.
 
Renewables vs. Fossil Energy Contributions During the Weather Event

Much has been actively debated about whether this emergency, in a state which is the largest net producer of energy in the U.S., was driven by a failure of large-scale renewables introduced into the electrical grid, or instead by the mainly fossil energy baseload, which is comprised of significant volumes of natural gas-fired capacity, with additional numbers of large coal plants.  In reality, all systems were impacted. On the wind energy side, with frozen turbine blades and low wind conditions, the 25,000 MW of installed capacity dropped to 3,000 MW and then down to just 20% of that amount during brief periods.  Solar suffered a similar fate, with panels covered with ice and snow.  On the fossil fuel side, natural gas comprises the largest share of baseload power capacity in the state.  Also, it is the vast majority the incremental reserve capacity.  During the height of this energy emergency, natural gas generation dropped by 31,000 MW. Power generation from coal, while forming a declining share of the Texas electrical market, dropped below 40% of its normal running capacity in similar situations. Much of the drop on the fossil side was due to frozen water pipes used for cooling, supply lines freezing, or a combination of both.
 
Regulatory Challenges

Texas has a somewhat unique power grid regulatory system in place called the Electric Reliability Council of Texas (ERCOT).  This council functions as the manager of the electrical grid in the state, not the power generator.  In their role they have been advising the in-state power generation industry to “harden” their abilities to withstand the type of cold conditions experienced most recently.  But those directives are voluntary and have largely not been heeded, primarily due to weatherization costs and demand for low priced power.  Texas also has a grid which functions more like an electrical island in the U.S., meaning it has very few interconnections to the rest of the large regional grids surrounding the state. All this at a time when over 60% of the state’s residential heat is now powered by electricity-based systems, which caused an additional surge in demand.  It is worth noting that many of the surrounding states did not have enough additional capacity at the critical time to cover the full lost generation in Texas, even if the interconnections had been in place.

As an outcome of this event, much of the ERCOT council leadership is resigning, political inquiries are moving forward on many fronts, and a range of lawsuits are already being announced.  And although failure to protect the systems was paramount, it cannot be forgotten that many lives were not only severely disrupted by this event, but many were also tragically lost. 

For additional information, contact Tom at tmurphy@psu.edu

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