The Texas Interconnection, which covers 213 of Texas’ 254 counties, is managed by the Electric Reliability Council of Texas (ERCOT). Counties NOT included: Bailey, Bowie, Camp, Cass, Cochran, Dallam, El Paso, Gaines, Gregg, Hansford, Hardin, Harrison, Hartley, Hemphill, Hockley, Hudspeth, Hutchinson, Jasper, Jefferson, Lamb, Liberty, Lipscomb, Lubbock, Marion, Moore, Morris, Newton, Ochiltree, Orange, Panola, Polk, Sabine, San Augustine, San Jacinto, Shelby, Sherman, Terry, Trinity, Tyler, Upshur and Yoakum. (Total = 41)
By now, you’ve likely read or heard numerous stories of Texans’ suffering because of electrical power outages, that are now becoming rolling blackouts.
And, perhaps as well you’ve read that deregulation has been a significantly influential part of the problem.
And then, you may have also read or heard that failure to properly insulate and protect against wintry weather conditions has been the preliminary finding of a root cause analysis.
But you may also wonder why other states or nations which regularly experience much colder temperature extremes don’t have the same kinds of problems that Texas has.
Scandinavian countries, Minnesotans, Michiganders and Mainers all regularly have much cooler temperatures and wind power, but their windmills and electrical power grids don’t stop operating like the ones in Texas did. And Germany, Switzerland, Austria, Hungary, and other European nations also regularly have cold weather that doesn’t shut down their power grid. So, what gives?
The weather-related failures of Texas’ natural gas (NatGas) infrastructure that has resulted in this present and most unfortunate crisis, are because NatGas pipelines froze in the very time of year and season in which they are most heavily relied upon.
Again, states and nations with much colder climes don’t seem to have the kinds of problems that Texas is experiencing. And there remains at least 42 signatory nations with permanent, year-round research stations in the Antarctic, which also have electricity. So again, why exactly did natural gas pipelines freeze in Texas? Water is the primary thing that freezes, right?
With single-digit temperatures, Texas’ Natural Gas pipelines froze up because there was moisture in the gas. Like moisture on the exterior of an iced beverage glass, cold temperatures cause moisture to condensate, and once liquefied, then exposed to freezing temperatures, gas pipelines were literally blocked with ice, and in some cases, the compressors lost power. It’s common for Natural Gas to be stored underground, which is also where it originates. So in its “raw” state, or untreated condition, it is not uncommon for water – either as liquid, or vapor – to be present in the unrefined gas, which in turn, must be “dried out,” or dehumidified to certain levels in order to be salable and usable.
In response, pumps which were used to deliver Natural Gas then slowed down. The Diesel engines which were used to power the pumps refused to start. And from there, it was a cascade of failures – a “domino effect” – one power plant after another went offline. Even 1 of Texas’ 2 nuclear reactors went dark, hampered by inoperable equipment. And to be certain, the nuclear power plant wasn’t “crippled” in the sense that it was incapable of operations, but a decision – in the interest of safety – was made to shut down the plant because a critical component – a sensor – was not working because of the cold temperatures. Further complicating matters, the NatGas that was available was prioritized for heating residences and businesses, rather than for generating electricity.
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“The measurement of moisture in natural gas is an important parameter for the processing, storage and transportation of natural gas globally. Natural gas is dehydrated prior to introduction into the pipeline and distribution network. However, attempts to reduce dehydration result in a reduction in “gas quality” and an increase in maintenance costs and transportation as well as potential safety issues.. Consequently, to strike the right balance, it is important that the water component of natural gas is measured precisely and reliably. Moreover, in custody transfer of natural gas between existing and future owners maximum allowable levels are set by tariff, normally expressed in terms of absolute humidity (mg/m3 or lbs/mmscfh) or dew point temperature.
“Prior to transportation, water is separated from raw natural gas. However some water still remains present in the gaseous state as water vapor. If the gas cools or comes in contact with any surface that is colder that the prevailing dew point temperature of the gas, water will condense in the form of liquid or ice. Under pressure, water also has the unique property of being able to form a lattice structure around hydrocarbons such as methane to form solid hydrates. Ice or solid hydrates can cause blockage in pipelines. In addition, water combines with gases such as Hydrogen Sulfide (H2S) and Carbon Dioxide (CO2) to form corrosive acids. Water in natural gas also increases the cost of transportation in pipelines by adding mass and as water vapor has no calorific or heating value it also adds to the expense of compression and transportation. When natural gas is sold, there are contractual requirements to limit the concentration of water vapor. In the United States the limit or tariff is expressed in absolute humidity in units of pounds per million standard cubic feet (lbs/mmscf). The maximum absolute humidity for interstate transfer is set at 7lbs/mmscf. In Europe, bodies such as EASEE-gas make recommendations on the maximum permissible amount of water vapor in the gas. EASEE-gas has approved a limit of -8°C Dew Point, referenced to a gas pressure of 70 Bar(a). This recommended limit is generally being adhered to in the gas industry across Europe.”
–– “Moisture Measurement Technologies for Natural Gas,” By Gerard McKeogh, Regional Product Manager, GE Measurement & Control
“Water content of high pressure natural gas: Data, prediction and experience from field,” by Kjersti Omdahl Christensen, Torbjørn Vegard Løkken, Even Solbraa, Cecilie Fjeld Nygaard, Anita Bersås;
Equinor, a Stavanger, Norway-based international energy company, engaged in exploration, development and production of oil and gas, including wind and solar power. They sell crude oil and are a major supplier of natural gas, with activities in processing, refining, and trading.
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