It has now been a year since discussions of the Texas Electricity Grid grabbed headlines as Winter Storm Uri bore down on Texas. In our debut episode, we introduced the interactive Texas Generation Model, which allows users to choose the generation mix for the state of Texas and determines how that portfolio performs when compared to electricity demand. The “what-if” analysis capability of this model allows us to discuss outputs and their importance in shaping the future of energy. In this episode, the model uncovers challenges and capacity demand that regulators, utility executives, and customer advocacy groups should consider as coal phases out and renewable resources become king.
Renewable energy has been gaining momentum and is expected to grow to 42% of the U.S. electricity generation mix in 2050 according to the 2021 U.S. Energy Information Administration Annual Energy Outlook. As we continue to see renewable resources, primarily wind and solar, replace carbon-emitting resources like coal, operating characteristics, such as ramp-up electric production speed from their baseload counterparts, raises new challenges and questions of adequacy.
For example, if we run the model in “carbon-free” mode, we see the urgency behind replacing the current frontrunner in Texas generation—natural gas. We can also consider other renewable resources, such as hydroelectric generation, but the long lead times for project development for new hydroelectric generation led us to use it as-is for the model. So, what is the answer?
To make up for the energy shortfall in the “carbon-free” scenario, first, try doubling the current level of wind and solar generation resources. The gap between electricity demand and energy produced gets considerably smaller, and we start to see instances of excess energy in the March and April 2021 timeframe. When analyzing the hourly breakdown of energy generation, wind and solar resources produce less energy in the evenings, so another dispatchable resource needs to ramp up and close the demand and supply gap. For example, look at a single day, like November 2, 2020, where there is more than enough output except for a few hours in the afternoon where the electricity output falls short of demand. Under today’s generation mix, the resource making up for the shortfall in electricity supply is typically natural gas “peaker” plants. Utility-scale battery storage energy is one solution, and the possibility of advanced nuclear is another (we will discuss both topics in upcoming episodes).
Now, try a generation portfolio scenario where there is four times the amount of wind and solar resources. As shown by the model results, the demand and supply gap decreases—on most days, the demand is met or exceeded. However, there are times when demand falls short of the energy supplied. February (the time of Winter Storm Uri) is not the only instance of a significant demand and supply gap. For instance, September 2020 was a time of sustained low winds where ERCOT sent notices asking Texans to consume less electricity.
One of the significant challenges with renewable energy development, especially wind—is surface area. When wind and solar resources are quadrupled in the Texas market, the surface area required for that development is equivalent to an additional 111 Washington DCs or 5,500+ square miles. When deciding where to put a generation facility, factors such as transmission access, grid capacity, resource availability (is it a windy or sunny spot?), and nearby neighbors need to be considered.
The availability of wind and solar (i.e., energy production) will vary each hour. An important aspect of increased solar and wind generation is what the model notes as “excess energy.” In our view, each area of excess energy that shows up on the model is an opportunity. As more renewable resources become available on the grid, the associated excess energy production can support new and growing electric applications.
For instance, co-generation. Why not use the power to generate another resource such as hydrogen? Another opportunity is diverting it toward mining cryptocurrency. ScottMadden has supported clients with business cases for both options.
Excess energy can support many other opportunities, such as charging electric cars or fleets. One solution to help level the demand-supply curve is utility-scale storage. With large storage facilities under development, will this help even out the peaks and valleys on the graph? Stay tuned for our next episode, where we dive into long-duration storage.
Additional Contributing Authors: Bill Hosken, Morgan Schadegg, and Chris Vlahoplus.
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