1 Introduction

1.1 The current grid…

Before going into some of the most amazing specifics about the U.S. energy grid, it is vital to comprehend how it works on an elementary level. The United States electric power system has assimilated several generations of new technology and improved its performance accordingly. Changes in federal transmission siting policy and power system design and operation will be necessary to efficiently sustain increased generation from large-scale variable energy resources (VERs), principally wind and solar power plants.

There are hundreds of power plants settled throughout the country that produce electricity. These are connected to transformers that step up the current voltage to be transmitted; high-voltage transmission lines connect these and then carry the electricity long distances across the country. There are over 450,000 miles of these energy lines today, as well as 160,000 miles of overhead transmission lines. [1]. After the electricity has moved a long distance, it is connected to a neighbourhood transformer. This steps down the voltage and conducts the energy through smaller, lower voltage lines. The energy is then allocated to poles which step it down again and ultimately send a safe amount of electricity into American homes.

The costs of distribution and transmission networks are mainly independent of usage in the short run, but they are generally recovered through volumetric charges. In the US, the cybersecurity of the bulk power system is inscribed in standards developed by the North American Electric Reliability Corporation (NERC)—it is not trivial that a single federal agency is given responsibility for cybersecurity throughout the grid, along with the necessary regulatory authority. The grid of 2030 will be much more automated and data-intensive than it is today, but the result of turning on a lamp will remain unchanged.

The U.S. does not actually have a national grid. Instead, it is split into three regions—the western interconnection, the eastern interconnection, and Texas—that primarily operate independently and exchange very little power. Power experts have known for years that this is a barrier preventing all sorts of efficiencies [2].

1.2 …and why it isn’t fully interconnected

A national U.S. power grid would make electricity cheaper and cleaner. A continent-wide super grid would let Pacific Northwest hydropower flow to Chicago and let Texas wind power find its way to Mississippi, Massachusetts, and Montana. It would allow managers to transmit the tens of gigawatts of wind-generated power from the Great Plains to cities on both coasts too. The paybacks, measured in financial and reliability terms, would be fantastic. And yet, even with many studies and several attempts to create such a grid, it has never been achieved. The technology, but mostly the political will have been lacking.

Although electricity networks are a valuable economic resource for electric utilities, developing an institutional structure that can encourage the creation of efficient networks has been elusive. The economic benefits and the control problems of electricity networks have repeatedly created situations where public policy has intervened in the industry’s structure, often resulting from unintended consequences arising from the interaction of previous policy and the desirability of more extensive electricity networks.

AC introduced the possibility of electricity networks, and the benefit of those networks prompted the entire industry to adopt this technology. The rise of these networks, albeit small, helped create the conditions that led to state regulation. That system, in turn, inhibited the development of larger and more economical networks. The growing recognition of the benefits of those networks, combined with the impediments of state regulation, helps create the holding company system. Problems with the holding company system resulted in proposals to radically restructure the industry.

Increased Federal Power Commission regulatory authority would partly offset the greater difficulty associated with unitary ownership of networks. The fact that State regulatory commissions saw this as a threat to their power resulted in the passage of a law inhibiting the more efficient deployment of electricity resources in the nation, creating an environment likely to produce more difficulties with the organization of U.S. electricity networks.

Figure 2. Power lines near Pinal, Arizona. Source: “Rural electricity” by Kevin Dooley is licensed under CC BY 2.0.

1.3 A proto-super grid

The benefits of broader electricity networks were recognized as early as the 1920s, resulting in two well-publicized proposals advocating significant modifications in the layout of power stations in the northeastern United States. Despite their similar designations (“Superpower” and “Giant Power”), the two plans had fundamentally different goals.

The Superpower proposal was a richer demonstration of both the potential rewards of a larger, fully-integrated electricity network and the fact that industry observers recognized those advantages at the time. It also shows how formal regulatory frameworks may obstruct the efficient restructuring of the electric power industry. William S. Murray, an electrical engineer and qualified consultant authored the Superpower proposal [3]. His enthusiasm led him to advocate a large-scale study to measure the benefits of an electricity network in the industrial Northeast, the region between Washington, D.C. and Boston, which was named the Superpower zone.

The “Superpower Report” was published in 1921, and the objective of the engineering team was to design a power network that was entirely integrated and in full operation by 1930. Railway companies were considered significant customers, and engineers anticipated that all railroads in the area would operate jointly. A secondary study of industrial demand was conducted to see how much money might be saved by switching from isolated plants to network supply. For that aim, a special tabulation of the Census of Manufactures was created. A study of the electric utilities in the Superpower zone was undertaken to assess the condition of generating and transmission infrastructure in 1919.

The engineering staff estimated the costs of electricity supply both with and without integration. The initial investment would be about $90.6 million annually for the first five years and $48 million annually for the next five years. The higher initial costs stemmed from the new transmission lines. By contrast, the capital needs of the unintegrated system were estimated at $85.6 million annually for the entire ten years. The report compared the sums of these two investment streams and concluded that the Superpower system would save $163 million. The predicted savings in annual total costs were even more dramatic. The net yearly cost advantage of the Superpower system was estimated at $151 million by 1925 and $239 million by 1930.

The Superpower Report’s major achievement was to measure clearly the benefits from an integrated network. The careful engineering work on the physical description of the proposed network contrasts with the absence of discussion of its business organization. Apparently, a new entity separate from the existing utilities would own the new generating stations and transmission lines—this was never stated. To achieve industry acceptance, the plan required two missing features: a workable business and financial organization for the network and a transition plan ensuring that the parties involved, particularly the existing electric utilities, would individually benefit from both the transition and the eventually integrated network. Implementation of the Superpower plan ultimately failed because existing utilities could not reach a joint agreement.

The tendency to concentrate ownership within the industry provided a significant stimulus for another integrated network proposal during the 1920s, the Giant Power plan [4]. Unlike the Superpower plan, the Giant Power proposal was a Pennsylvania state legislative proposal backed by the governor and applied only locally. Although western Pennsylvania was a central coal-producing region, the heavily industrialized eastern portion of the state, a major component of the Superpower zone, was a promising area for an integrated electricity supply network. Giant Power proponents intended Pennsylvania as a model for the national industry.

The most exciting feature of the Giant Power plan was its proposed industry structure, which attempted to simultaneously check the growth of monopoly power, improve public regulation, and support the development of a fully integrated network. Eventually, existing utilities were of one mind about Giant Power: strong opposition. William S. Murray referred to the plan as “communistic.” Despite a long political battle, the Pennsylvania legislature never accepted the proposal.

2 Latest Advances

2.1 Tres Amigas

Some years ago, engineers made a major stride: an ambitious project known as Tres Amigas was finally getting underway. Eventually, it would link the three largest North American grids: the Texas Interconnection, the Eastern Interconnection, and the Western Interconnection, which together cover the lower 48 states plus 8 Canadian provinces. The long-delayed Tres Amigas facility, located in eastern New Mexico, where the three grids converge, would be a transmission “superstation,” able to carry up to 20 gigawatts of electricity in almost any direction [5].

Figure 3. Site for the Tres Amigas superstation outside Clovis, New Mexico. Source: https://spectrum.ieee.org/will-the-us-finally-get-a-unified-power-grid

In November 2016, construction workers began erecting the first piece of the first phase of the project: a 56-kilometre carrying line to connect three new wind farms to the superstation hub and then to a substation called Blackwater, which connects to the Western grid. The 345-kilovolt line was then electrified, and Blackwater would also have to be upgraded to handle the extra capacity of up to 500 megawatts of wind power. With an estimated placeholder of US $1.6 billion, the ultimate plan was to construct three more lines to substations in Texas, one of which connected to the ERCOT (the Electric Reliability Council of Texas), and the other two connecting to the Eastern grid.

The four arrays of transmission lines would converge at Tres Amigas, a 58-square-kilometre site where the utility will install high-voltage DC converters for converting AC to DC and back again, plus an unpretentious 5 MW of storage for regulating voltage and frequency—additional converters and storage may be added as new partners sign on. Other plans suggest an electricity-market hub to let traders take advantage of the differences in fees between regions; capitalizing on such disparities should lower rates for customers and stimulate more investment.

A high-voltage DC node that connects AC networks—a configuration labelled as an HVDC overlay—will make the whole grid more stable and responsive to outages and faults. Extensive, unified AC systems tend to get unstable. With its ability to move much power quickly, an HVDC overlay will provide a considerable reliability enhancement as the electricity grid grows. For instance, China and India are installing transmission grids based entirely on HVDC [6].

In February 2017, The Associated Press reported statements from Tres Amigas officials, saying technology leaps and changes in the project’s business model had reduced the amount of money and land required for the project. The facility would just be connecting the western and eastern grids initially. Officials stated that the company’s focus continued to connect independently operated electrical grids and move renewable energy generated in the rural spots of Eastern New Mexico to western U.S. population centres. Word of the project fell silent after that.

Today, five years later, the Tres Amigas is not a reality. The superstation that never came to be might have helped this year (2021) with Texas/New Mexico blackouts inspired by subzero temperatures, but it likely would not have prevented them. It is said that the Tres Amigas project failed to come to fruition was because ERCOT, the Texas power grid, would not agree to connect [7]. Regarding a project like this ever coming to completion, that will depend mainly on energy industry policy and economics.

2.2 The Macro Grid Initiative

In the mid-2020, The Americans for a Clean Energy Grid (ACEG) and the American Council on Renewable Energy (ACORE) launched the Macro Grid Initiative to build support for expanding and upgrading the nation’s transmission network. According to them, a modern Macro Grid will deliver jobs and economic development, a cleaner environment, and lower costs for consumers [8].

The need to improve America’s outdated and fragmented electricity transmission system both to tackle the climate crisis properly and to compete effectively in the 21st-century economy was the primary motivation for ACORE executives. A Macro Grid will allow for better integration of low-cost renewable resources, resulting in a more resilient, competent grid and a dramatic reduction in carbon emissions.

Figure 4. An estimated 2030 balance of power supply and demand for each region of the country. Source: https://www.vox.com/energy-and-environment/2020/6/20/21293952/renewable-energy-power-national-grid-transmission-microgrids

Upgrading the U.S. transmission system is a cost-effective way to alleviate transmission congestion and better integrate new generation. Renewable energy growth accelerates due to competitive prices, higher demand from corporate and residential consumers, and aggressive state renewable energy programs. The initiative will undertake wide-ranging educational efforts in support of transmission expansion to connect areas with low-cost renewable resources to centres of high electric demand. This can be accomplished by connecting grid regions like MISO (Midcontinent Independent System Operator), PJM and SPP (Southwest Power Pool).

Experts in charge believe every supporter of clean energy should support a more robust backbone transmission grid. ACEG looks forward to working with ACORE to explain to the public and policymakers why that is the case and build support for its development. Working out the Macro Grid vision will require new federal, regional, and state policies that recognize the valuable nationwide benefits of an interregional connected transmission network.

3 Conclusion

Electricity is the fuel of the future. And as more and more of daily life is electrified—buildings and transportation are already on their way—the electricity grid will face growing demands and will need to evolve to meet them. One branch of that evolution is “bigger”. The US does not actually have a national grid. It is instead split into three regions—the western interconnection, the eastern interconnection, and Texas—that largely operate independently and exchange very little power.

Several recent studies have already shown the tremendous benefits of expanding the country’s transmission grid. For example:

  • Upgrading and expanding interregional transmission lines would help corporate and institutional buyers, electric utilities, and other consumers meet carbon goals by inexpensively and reliably integrating low-cost renewable energy inputs. Improved transmission will also facilitate increased electrification and ensure grid reliability in the face of new electricity demand patterns.
  • Increasing transmission development at the interfaces between regions could save consumers money and return for every dollar invested by operators.
  • A nationwide HVDC network optimized for the nation’s best solar and wind resources could deliver substantial carbon emission reductions from the grid by 2030.

4 References

To all knowledge