Increasing Demand on the US Electricity Grid
Electricity demand in the U.S. is surging, leading to more frequent failures in the system as it nears its physical limits. The number and seriousness of these issues are likely to grow if things continue as they are.
Although there’s been a lot of discussion about how we need more power generation, it’s worth noting that without a strong network of transmission lines connecting generators to local distribution systems, that power can’t effectively reach the billions of devices that rely on it.
The current system is quite a jumble, with overlapping jurisdictions and competing state interests complicating the management of our 21st-century electrical economy. The approval processes involve numerous redundant decision-makers, based on outdated laws that were established when interstate electricity transmission was still developing. This leads to decisions made locally that often overlook the best new technologies that could enhance economies of scale and improve overall interconnections.
For instance, high voltage direct current (DC) systems have the potential to overlay alternating current (AC) grids, vastly improving the transmission capabilities over long distances. Nevertheless, optimizing these high voltage DC systems requires a comprehensive understanding of the entire electrical network.
Additionally, the average power line is between 40 and 50 years old. Getting a new project approved can take years, and proposals aimed at meeting basic reliability standards are frequently shot down for political reasons or dropped altogether by backers as costs rise and delays accumulate. Given that the grid is approaching its physical limits, the delivery capabilities of AC systems are hindered, leaving areas in need even if low-cost generators are functioning at peak performance.
Recently, during a stressful heat wave, the Northeast was near a critical tipping point where generation from surrounding areas couldn’t be utilized to ease the burden. According to a report from the North American Electric Reliability Corporation (NERC) for 2024, an additional 35 GW of transfer capacity is necessary across the national grid.
Electricity doesn’t flow like water in pipes; it’s more complex than that. Changes in supply or demand can rapidly alter power flows throughout the East (600 GW), West (160 GW), and Texas (95 GW) AC interconnections, governed by the inherent laws of electricity.
This rapid-response requirement means that supply must consistently match demand, maintaining a frequency of 60 Hz and ensuring that transmitted energy doesn’t exceed the capacity of individual transmission lines. Every second, sophisticated computer systems analyze sources, lines, and usage to pinpoint limitations caused by any changes, helping operators respond effectively.
Since adjustments impact the entire AC network, thorough long-term research is necessary to incorporate new systems, which is a slower process than it should be.
This isn’t merely a U.S. issue; other countries, particularly in Europe and Asia, have been addressing similar challenges for some time.
For example, starting in 2005, China began implementing high voltage DC systems to overlay its 1300 GW AC grids. This effort has produced a hybrid grid with 55 HVDC lines, totaling 170 GW in transfer capacity, with additional lines currently being built. Some of these HVDC lines stretch over 1,500 miles, and a new 12 GW line even exceeds 2,100 miles, comparable to linking California with the Mid-Atlantic regions.
In Europe, a coalition called “Friends of the Supergrid” was formed in 2006 to explore a high voltage DC supergrid alongside a 540 GW AC grid. Europe has also established ENTSO-E, a group that includes all transmission owners collaborating on mass transmission needs and coordinating plans with the European Union.
However, the U.S. is not fully capitalizing on high voltage DC technology or other advancements. A study from 2016 by Alexander MacDonald, based on a decade of NOAA supercomputer analyses, indicated that for every dollar invested in high voltage DC, there could be a return of three dollars, while significantly reducing carbon emissions.
There are chances to enhance existing conductors through the use of composite core materials, which can boost line capacity. Meanwhile, a new technology called grid-forming inverters allows for rapid detection of system abnormalities, crucial as aging machinery reaches the end of its operational life.
If these challenges remain unaddressed, the U.S. will struggle to meet the energy demands of its growing economy, necessitating an upgrade of the National Electric Grid. This effort should focus on three essential components:
- First, akin to the development of transcontinental railroads and interstate highways, there needs to be a national network of buried high-voltage DC lines that overlay existing AC systems. This approach not only improves security and reduces environmental impacts but also allows placement along existing AC transmission routes.
- Second, enhancing the capacity of current AC networks by converting critical circuits to composite core conductors without taking lines offline is important.
- Third, the advantages of grid-forming inverters for the reliability of real-time grids are quite clear. Prioritizing their installation is crucial.
The increasing demand for energy is approaching quickly, and, frankly, we’re not adequately prepared. By focusing on these three priorities, we can help ensure there’s sufficient reliable energy to support the growth of the U.S. economy.
