According to recent analysis, a’macrogrid’ that boosts the amount of energy travelling between America’s Eastern and Western interconnections, two of the world’s largest power grids, would more than pay for itself.
Seven little threads link two of the world’s most powerful electricity systems.
Those seven threads (officially, back-to-back, high-voltage, direct-current connections) link America’s Eastern and Western interconnections and have a total capacity of 1,320 megawatts. (The seam that divides the grids extends approximately from eastern Montana to the western borders of South Dakota, Nebraska, and Kansas, as well as the western boundaries of the Oklahoma and Texas panhandles.) Texas is primarily outside the two major grids since it has its own grid.)
The eastern grid has a producing capacity of 700,000 megawatts, whereas the western system has a capacity of 250,000 megawatts. So there isn’t much power going between the two at up to 1,320 megawatts.
But what if the links between the two grids were stronger? What if there was more electricity flowing back and forth? Could Iowa wind power, Southwest solar power, and Eastern off-shore wind power be moved from coast to coast as a result of this? Is it possible for the West to assist the East in meeting peak demand, and vice versa? Would more connections improve grid resiliency, adaptation, and reliability? Would the advantages outweigh the disadvantages?
Yes, in a nutshell
According to the Interconnections Seam Research, a two-year, $1.5 million study initiated as part of the US Department of Energy’s $220 million Grid Modernization Initiative announced in January 2016.
Early results were discussed at a 2018 conference at Iowa State University, and the newest findings were published in two articles released this summer and autumn by IEEE, the Institute of Electrical and Electronics Engineers.
Grid improvements in modeling
Engineers from Iowa State provided their computer modeling skills to the project, creating a capacity expansion model that replicates 15 years of power production and transmission upgrades. The model contains four cross-seam transmission designs and eight generating scenarios with varying transmission costs, renewable energy output, gas prices, and power plant retirements.
The grid-improvement procedure was projected to last until 2038 in the Iowa State models. The 2038 data was utilized by researchers at the National Renewable Energy Laboratory in Colorado to create an hour-by-hour model of one year of power-sharing across the seam.
According to a summary of the latest paper, “the results show benefit-to-cost ratios as high as 2.5, indicating significant value to increasing transmission capacity between the interconnections under the cases considered, realized through sharing generation resources and flexibility across regions.”
“You receive up to $2.50 back for every dollar invested,” said James McCalley, an Iowa State Anson Marston Distinguished Professor in Engineering, the Jack London Chair in Power Systems Engineering, and a co-author of the articles.
How much money would you need to put up?
According to McCalley, building a “macrogrid” of large transmission lines that circle around the Midwest and West, with branches filling in the center and connecting to Texas and the Southeast, would cost around $50 billion.
Determining the worth
According to the researchers’ article released this summer, the more transmission across the seam, the better.
“The B/C (benefit-to-cost) ratio follows cross-seam transmission capacity: the conditions with the greatest B/C ratio are the ones with the highest cross-seam transmission capacity,” the researchers said.
“Cross-seam transmission pays for itself: This shows that under conditions associated with a high-renewable future greater than 40%, cross-seam transmission benefits exceed costs, based only on a 35-year period to assess savings generated by generation investments and operational efficiencies,” according to one of the study’s key findings.
According to McCalley, the macrogrid pays for itself in three ways:
1. Various sections of the nation experience peak demand at different times throughout the day. Different areas may work together to reach their daily peaks using a macrogrid.
2. As coal and gas-fired power facilities are decommissioned, a macrogrid enables for the sharing of wind and solar-power resources throughout the nation. “We manufacture wind energy in the Midwest,” McCalley said. “The Midwest, on the other hand, has a smaller population. As a result, we must shift that energy.”
3. Utilities must now construct more capacity to satisfy the year’s peak demand. A macrogrid may assist various sections of the nation in meeting each other’s peak demand, reducing the amount of peak capacity that must be developed in any one location.
What about storms like the derecho that hit Iowa in August 2020 or the ice storm that knocked out electricity in Texas in February 2021? Could a macrogrid be useful in such situations?
“Being able to cope with these kinds of resilience concerns is another advantage of the macrogrid,” McCalley added. “You might easily get electrical help from other areas. Iowa and other states would be linked to other regions.”
While studies are starting to evaluate the utility of an American macrogrid, McCalley believes there are several obstacles to its construction. There is, without a doubt, a cost. There will be policy and political choices to make. There are also others who oppose transmission lines, wind turbines, or solar panels near their homes.
What does he have to say to them?
“My attitude has been that there are disadvantages to any kind of energy,” McCalley stated. “Tell me if there’s a better option.”
