WHAT IS HAPPENING IN THE ENERGY CAPITAL?
February 18, 2021 § 14 Comments
Texas prides itself on being the energy capital. The capital (as opposed to the Capitol of the infamous January 6 insurrection) is under siege. Nature is asserting its might. Unpreparedness sure helps.
Few know that Texas has its own grid. The country is divided into three grids: The Eastern Interconnection, the Western Interconnection, and drum roll here, Texas. Conspiracy theorists may connect this to secessionist tendencies. Certainly, recent utterances attributed to the former governor Rick Perry don’t help. He is quoted as saying, “Texans would be without electricity for longer than three days to keep the federal government out of their business,”. He is referring to the fact that because the Texas grid does not conduct interstate commerce, it is not governed by the rules of the Federal Energy Regulatory Commission. This from a guy who just a month ago held federal office as the US Secretary of Energy.
In a Fox channel interview Governor Abbott of Texas blamed solar and wind for the problem. Small problem: solar is just 1 – 3% of the total and wind is around 20%. Then his own folks at ERCOT, which stands for Electric Reliability Council of Texas (the reliability in the name is ironic) said it was primarily due to natural gas supply drop. This makes more sense because gas generators comprise 47% of the electricity produced. Abbott later walked back the claims and said he meant that renewables could not be the dominant source. Tell that to Germany, which gets 40% from renewables. Then Congresswoman AOC trolled Abbott by Tweeting that Texas electricity was 80 – 90% from fossil fuel. That is not accurate either (coal plus gas come in at about 65%, according to ERCOT). Just when you think the election silly season is over, you have politicians using their favorite political points scoring issue whenever there is a remote opening for it.
By all accounts, every source of electricity was hampered by the extreme cold, even the nuclear plants. But, according to the ERCOT leadership, the biggest culprit was natural gas. Delivered natural gas nearly halved at the most severe stages due to frozen lines. We know that methane (the dominant component of natural gas) does not freeze till a frigid -182 C. So, why are natural gas pipelines (these are the main supply lines, not the little ones going to your house) freezing?
I was not able to find any explanation, so I am going to hazard a hypothesis based on other oilfield knowledge. Almost all supplies of natural gas will be water wet to some degree. If films of water form, at pipeline pressures of 800 psi or so, temperatures approaching water freezing can cause hydrate crystals to nucleate on the walls. Again, with the right conditions, these could grow to plug the line. This routinely happens in undersea gas pipelines. Those pipelines have a device known as a “pig” which can be made to traverse the line and mechanically clear out the growing crystals. The other means is to drizzle in methanol, which lowers the freezing point; basically an antifreeze such as ethylene glycol in your car radiator (which too can be used in this application).
Gas hydrates are large crystals of ice with methane in the interstices. The overall crystal structure looks like a soccer ball. Richard Smalley, who co-discovered this structure in carbon (a sixty-atom molecule version), got the Nobel Prize for it, in part because finding a brand-new crystal structure of a common element is rare, and in part because carbon in this form has proven to have compelling value in the form of nano materials. Gas hydrates in the subsurface were once believed to be the next big thing in natural gas sourcing because they are ubiquitous and, according to the US Geological Survey, the total resource exceeds all other carbonaceous fuels combined. Some probably still are believers. In my opinion plentiful shale gas has shot down those dreams. Gas hydrates are also a neat party trick. Take a block of it in a shallow bowl and the seemingly innocuous ice will light up with a match.
We can conclude from all that we have seen in Texas that industry, especially a loosely regulated one, operates on probabilities. ERCOT modeling probably predicted such freezes to be infrequent and more geographically scattered, allowing the management with a minimum of disruption. Not the way it turned out. Last year a high proportion of the devastating wildfires in California were known to have been triggered by downed power lines. A cost-effective solution is yet to be identified. The Lone Star is not alone after all.
February 18, 2021