Development of new high-voltage transmission lines could provide myriad benefits for the U.S. electricity system, including improved reliability, greater sharing of resources across regions and a means for states to achieve environmental policy goals, FERC said in a recent report to Congress.

But such a transmission buildout also faces significant obstacles, given the patchwork of federal and state regulations developers must navigate to develop projects, including in existing rights of way.

The report is a product of the 2020 Further Consolidated Appropriations Act, which directed FERC to provide the appropriations committees of both houses of Congress with a study “outlining the barriers and opportunities” for high-voltage transmission in the U.S. Although the report was dated June, it was apparently sent to Congress last week.

While the report offers no concrete steps for policymakers to take, its findings offer a boon to renewable advocates, buttressing the case for building transmission to tap resources in remote areas with an argument favoring the accompanying reliability benefits.

“High-voltage transmission can improve the reliability and resilience of the transmission system by allowing utilities to share generating resources, enhance the stability of the existing transmission system, aid with restoration and recovery after an event, and improve frequency response and ancillary services throughout the existing system [while also] providing greater access to location-constrained resources in support of renewable resource goals,” the report says.

“Americans for a Clean Energy Grid is excited to see the strong endorsement of large-scale regional and interregional transmission,” said Rob Gramlich, the organization’s executive director and president of Grid Strategies. “The report begins an important national discussion about making much greater use of highway and rail corridors as a way around some of the well known barriers to transmission.”

Reliability and Resilience

FERC’s study defines “high-voltage” transmission as AC lines 345 kV or above and DC lines of at least 100 kV, including overhead and underground networks. It notes the land-use efficiency of transmitting power at higher voltages, which reduces line losses, ensuring that a greater volume of power generated will reach its destination.

“For example, one 765-kV line on a 200-foot-wide right of way can carry the same amount of power as 15 double-circuit 138-kV lines with a combined right-of-way width of 1,500 feet,” the report says.

The report addresses four key reliability and resilience benefits of high-voltage transmission:

• Sharing of resources across regions by improving interregional power transfer capability. FERC points out that high-voltage transmission can allow a region to access additional generation when local resources become unavailable. The report notes that during the 2014 and 2019 polar vortex events, the East and Midwest experienced high generator unavailability in concert with demand spikes. During the 2019 event, imports served 9% of load, compared with 3% during the 2014 event. But FERC cautions that “the potential benefits provided by proposed and existing high-voltage transmission are not uniform and need to be studied and verified with detailed simulation modeling of the transmission grid prior to integrating any proposed high-voltage transmission solution.”
• Aiding with restoration and recovery after an event. FERC said that during a wide-area blackout, system restoration can benefit from neighboring in-service transmission facilities to restore generation, lines and electrical service, especially in cases where local black start units become unavailable.
• Improving frequency response. The report notes that HVDC lines between neighboring interconnections can provide frequency support in cases of a large loss of generation.
• Enhancing the stability of the interconnection transmission system. Citing the operation of the Pacific DC Intertie linking the Pacific Northwest with Los Angeles, FERC notes that active modulation of the line has been used effectively to maintain system stability in the Western Interconnection “by dampening interarea modes of oscillation.”

The report also cites the recent CapX2050 study by 10 Midwestern utilities, which found that “retirements of dispatchable generation and the movement toward non-dispatchable wind and solar generation will change transmission congestion patterns and introduce more variability in power flows, thus requiring new solutions to mitigate congestion and ensure reliability.” (See CapX2050 Calls for More Tx, Dispatchability in Midwest.)

Opportunities, Obstacles

The “opportunities” section of the report points to trends that could fuel the development of new high-voltage transmission, including states’ renewable portfolio standards.

“These regulatory mandates and voluntary targets are contributing to the buildup of renewable energy resources (e.g., solar, wind, hydropower and geothermal) that are often located in remote areas far from population centers. Transmission developers have proposed numerous high-voltage transmission projects in the United States that could integrate renewable energy resources onto the grid and connect them to regions with high electricity demand,” the report says.

The report also points out that high-voltage transmission developers could benefit from the effort of states and localities to increasingly electrify transportation and building heating to reduce carbon emissions. It cites a 2019 Brattle Group study that finds “the U.S. will need an average investment of $3 billion to $7 billion per year through 2030, in addition to investments needed to maintain existing transmission systems and integrate renewable energy generation to meet existing load, to meet the changing needs of the system due to electrification.”

Another upshot of increased transmission buildout: improved competitiveness in wholesale markets through reduced congestion and the increased ability of low-cost resources to participate. To support the claim, FERC cited 2017 and 2019 reports from ISO-NE showing how new transmission could help New England integrate low-cost resources, decrease congestion and uplift costs, and reduce renewable energy curtailments.

The report delves into how transmission development could benefit from the existence of federal and state laws that support co-location of lines along transportation corridors, including highways, pipelines, railroads (both existing and retired) and canals.

“In some cases, the co-location of transmission in transportation corridors could reduce both the negative effects caused by a project and the cost of project development. Siting transmission in transportation corridors could minimize the creation of new rights of way on undisturbed lands, which could result in reduced effects on private landowners and environmental, cultural and visual resources,” the report says.

The report additionally points to FERC’s own efforts to encourage interregional transmission development, including issuing Order 1000 in 2011, which aimed to address deficiencies in the transmission planning and cost allocation requirements, including participation by nonincumbent developers in regional planning processes, interregional coordination, and methods to allocate the costs of new regional and interregional transmission facilities.

But FERC acknowledged that transmission development still faces significant barriers in the post-Order 1000 world, especially the number of new projects being developed outside the competitive processes envisioned in the order. Those include the continued ability of incumbent transmission owners to maintain a federal right of first refusal for local projects and upgrades, as well as the existence of threshold limits (such as costs and voltage levels) and other exceptions to Order 1000 requirements in regional planning processes.

“Some entities have suggested that incumbent transmission owner utilities may have a preference for developing projects outside of regional competitive transmission planning processes, which may obviate the need for longer-term solutions that might qualify for these processes,” the report says. “Others argue that the transmission development occurring post-Order No. 1000 is focused on reliability and local needs, with only a modest increase in regional projects to address market efficiency and public policy needs.”

The report also addresses barriers to development in co-location corridors. FERC points to the example of development along highways, where the Federal Highway Administration (FHWA) and state transportation agencies share joint authority. The state agencies develop the standards they will use to approve applications from utilities, which FHWA must review to ensure consistency with federal guidelines.

“Some states’ utility accommodation policies expressly prohibit transmission and other longitudinal utility facilities in highway rights of way. Others restrict the co-location of transmission in highway rights of way based on various factors (e.g., transmission voltage or specific highway features),” the report notes.

Siting of high-voltage transmission in other areas generally falls under state jurisdiction, requiring developers to negotiate multiple state processes, as well as those at the federal and local levels — and all this after navigating regional transmission planning procedures, FERC notes.

“The time required to develop a high-voltage transmission facility that meets mandatory reliability standards, maximizes system benefits and strikes a balance among interested stakeholders (including states) can be in excess of a decade,” the report says.