The U.S. Department of Energy has unveiled a comprehensive transmission planning study, an intriguing blueprint that outlines a framework for interregional transmission development. It’s particularly notable for highlighting “high opportunity” interfaces on the grid, poised to facilitate transformative connectivity between disparate regions.
This newly minted National Transmission Planning Study is a valuable asset for utilities and grid planners, as noted by Maria Robinson, the director of DOE’s Grid Deployment Office. “Think of it not as a rigid blueprint but rather a versatile toolbox,” Robinson articulated during a media briefing, emphasizing its role in allowing individual regions to tailor their own transmission solutions based on unique requirements and circumstances.
Crafted through a collaboration between DOE’s renewable energy and Pacific Northwest national laboratories, the study meticulously examines 96 diverse scenarios, integrating a plethora of sensitivities such as evolving electric demand, ambitious carbon emission targets, and cutting-edge transmission technologies. With an eye toward 2050, this expansive modeling dives deep, venturing to a nodal level of analysis—an advancement over earlier studies, as Robinson points out, extending its analytical reach through 2035.
Currently, the U.S. suffers from a conspicuous void in interregional transmission planning. This study intends to bridge that chasm, laying out potential pathways for grid planners eager to explore new options. At the heart of the study are the so-called HOT interfaces, identified as high-opportunity transmission points capable of delivering widespread benefits across various scenarios. These interfaces could become prime candidates for further exploration and might catalyze a new wave of accelerated transmission expansion.
Encompassing a mix of alternating current (AC) projects, point-to-point schemes, and versatile multiterminal high-voltage direct current (HVDC) projects, these HOT interfaces represent a spectrum of opportunities. The study elucidates that while HVDC is advantageous for long-distance power transfers, particularly between interconnections, AC network expansion will continue to dominate transmission infrastructure enhancements for many regions.
The implications of this research are substantial. The report forecasts significant economic benefits from dramatically building out interregional transmission capabilities. For instance, by 2050, implementing an AC buildout could yield a staggering savings of $270 billion, while point-to-point and HVDC expansions might reach savings of $380 billion and $490 billion, respectively, based on a hypothetical mid-demand scenario that targets a steep 90% reduction in power-sector carbon emissions by 2035.
Robinson highlights the necessity of balancing immediate costs with long-term benefits: “It’s crucial for electric consumers to think about costs, often more from a short-term perspective than a long-term one. This study allows us to keep our eyes on the future.” The findings suggest that for every dollar invested in transmission, a return of $1.60 to $1.80 in system cost savings is likely, thanks to broader access to affordable electricity and resource collaboration across regions.
Looking ahead, the Grid Deployment Office is committed to disseminating this study’s insights and analytical tools to a wide array of stakeholders—grid planning entities, operators, utilities, states, and tribal authorities—to drive forward interregional transmission planning at every conceivable level.
This initiative coincides with the North American Electric Reliability Corp.’s efforts to prepare a complementary study that will assess the capacity for power transfers between regions. As mandated by Congress, this pivotal report is set to be submitted to the Federal Energy Regulatory Commission by December 2, marking another step in reshaping America’s electrical landscape.