Power Production And The Texas Outage Of 2021
When it comes to producing electrical power, being an independent producer is quite beneficial. It is like a nation having the means to provide for producing their own electricity, from source to distribution. It can surely cut dependence on outside entities, commercial or otherwise, and boost the local economy (e.g. employment). The cost of electricity also comes cheaper because of less imports as inputs to production. This model is ideal, until disaster strikes. Unfortunately, that was what happened to the state of Texas.
The “Lone Star” Power Grid
Texas has its own state and private electrical grid networks that has made them independent from the rest of the US in terms of power production. The state’s grid is managed by ERCOT (Electric Reliability Council Of Texas), which oversees the majority of the state’s electrical power production and distribution. Texas (except for a few counties) is like an island isolated from the rest of the country when it comes to their power grid. That means that all power in Texas is distributed within the state only, there are no interconnections to power grid networks outside of the state.
The Texas power grid under ERCOT, consists of 46,500 miles of transmission lines and more than 650 power generation facilities (Per Texas government data). There are also private energy companies that provide electricity, but ERCOT is the main grid. The US Department of Energy lists Texas power consumption at 365.1 TWh (10% total U.S.), while producing 429.8 TWh (11% total U.S.) per annum. Not all energy is consumed, as a certain portion of power generation is lost to heat.
Texas Energy Sources
According to ERCOT (based on 2020 data), Texas has 4 primary sources of energy used for producing electricity.
- 46% Natural Gas
- 23% Wind
- 18% Coal
- 11% Nuclear
- 2% Other
Most of the state’s energy comes from fossil fuels (e.g coal and natural gas), but there is also a significant amount coming from wind, a renewable resource.
In terms of natural gas production in the US, Texas is the leader (as of this posting) with 23.9% of production. The state does not need to import natural gas, so the abundance of the resource can help produce electricity. Texas also holds 1/4 of the US natural gas reserves, so this resource is quite plentiful.
Texas was also able to harness power from the wind. Wind turbines convert the force of the wind into electricity through power generation from the speed of the wind. Stronger winds are ideal, and Texas has plenty of areas where the wind can provide sustainable energy needs. Wind has overtaken coal, as the move towards less carbon emissions takes over the consciousness of some policy makers.
While many would consider Texas to be a sunny state, solar power has not contributed any significance as an energy source. It will fall under the 2% other sources, which also includes biomass and hydro.
All together, these sources help produce the 429.8 TWh of power the state needs to provide among many things, the electricity to its residents.
The Polar Vortex
The Texas grid was the “achilles heel” that was struck during the polar vortex that occurred in early 2021 (mid-February) in the US. Extreme snowy and wintry weather is uncommon in Texas, though there have been incidents before(e.g. 1989 and 2011). The events from the past could have been a signal to prepare for the future. In this case, since events like these are rare, there were not many if any preparations for most of the state’s power production facilities. The extreme cold led to so many problems, the state’s electrical services could not handle the demand.
Coal plant stocks began to freeze. One of Texas’ nuclear power plants went off line due to the extreme weather. Several wind turbines stopped working due to the severe cold. The biggest system failure was with the natural gas power plants, as water vapor content in the gas froze preventing it from heating to produce energy. These sources were vital for meeting the state’s electrical power needs. The polar vortex crippled most of the state’s power generation facilities and distribution as well (e.g. power line damage). As the weather worsened, the power grid was affected as blackouts left millions of Texans without power. The state was just a few moments away from catastrophic power failure.
The Grid Failure
According to Insider:
If grid operators hadn’t acted quickly, parts of the state could have been without power for months.
That would be the catastrophe no one had anticipated. The blackouts could have been much worse in Texas, but mitigation efforts to fix the problem had a coordinated response.
The way to prevent power failure that could last for weeks to months was to begin rolling blackouts. The power grid operators need to do this in order to keep the power distribution network in synch. If a certain distribution center is not transmitting current at 60 Hz through the power lines, it can have consequences to the load applied on the circuit. Certain appliances would not function or even malfunction. If the line voltage drops, it will not provide normal electrical services to consumers.
When a drop off point is reached on the grid, operators will have to begin implementing rolling blackouts. The grid must maintain a certain level to provide electricity. The speed and frequency of an AC generator must match that of the other facilities in order to transmit electricity. When this is not the case, the grid operators need to shut off parts of the system to prevent a total blackout. There must always be a source ready to provide and distribute power on the grid. If the demand exceeds the supply of power, it can lead to a shutdown wherein no power is being generated.
Power plants and production facilities need to maintain inertia on the network. The entire grid must be synchronized to transmit power at 60 Hz for normal operation in Texas and the rest of the US. By implementing rolling blackouts, parts of the grid can operate without getting affected by more demand. It is a way to manage the supply of electricity without having to shut down the entire grid. It is all about maintaining reliability so that once a power distribution center has been restored, the system can be synchronized back to the network. It would be much worse if the grid operators allowed their remaining power to be depleted, so they had to shut off portions of the grid where supply could not meet the demand.
Weather proofing power production and distribution centers in Texas is going to be a vital task. Since Texas is isolated from the national grid, it has to take measures of its own to safeguard their facilities. It is still possible to produce electricity despite cold weather. In Alaska and Antarctica they are able to do so, yet it failed in Texas. The systems need to have some form of defense against ice formation and have a mechanism to address low temperatures. It has happened before in Texas, so the question is why was there no effort to implement weather proofing? Perhaps the answer takes on more complexity, but now it is apparent that something has to be done.
Another question is should Texas remain isolated from the rest of the grid? Oklahoma experienced the same weather phenomenon, but they were saved by neighboring states that provided their grid power when needed most. The same thing could have happened in Texas, but their grid has no interconnections to neighboring states. This is another question that has no easy answer. Instead there are proposals that can be made to help with these concerns.
A VPP (Virtual Power Plant) solution is one type of design that could help deal with power demands. If we look at the Texas power grid architecture, it is highly centralized and controlled by one entity. A decentralized power grid network that consists of many operators can create a macro-grid that functions as a virtual power plant. It is a system based on intelligent software (e.g. SDN smart grids) that distributes electricity across the network, by monitoring where demand is needed most. It forms what is called a negawatt market, which is a secondary market for electric power allocation. The business model is another story, but it can provide what I consider a backup solution.
In a VPP scenario, if Austin’ demand for power exceeds that of Houston, the Houston grid could distribute power to the Austin grid. The power comes from stored energy in battery units that can then provide backup power in the event of an emergency. In a centralized grid, although Houston and Austin are interconnected, the issue is that you cannot just transfer power if the source of the electricity is coming from the same facility. A VPP can be used as a backup to the existing power grid, not necessarily to replace it.
The lesson learned in this is that being prepared is the most important thing in any disaster. Being energy independent and having sources of renewable energy did not prevent the grid’s failure. Isolation does not help when the problem is statewide and renewable sources are intermittent and not immune to the weather. Instead, the approach should be about contingency measures and how to maintain normal operations in the face of a weather calamity. This time around the state and their grid operators have time to prepare until the next one comes along.