National Transmission Planning Study

The National Transmission Planning Study (NTP Study) sought to understand the transformation needed to ensure the U.S. transmission system continues to reliably serve the nation’s electricity customers.

The NTP Study was led by the U.S. Department of Energy’s Grid Deployment Office and conducted in partnership with NREL and Pacific Northwest National Laboratory. The study aimed to better understand the scope of interregional transmission needs as the power sector continues to evolve and transition to cleaner resources.

During the study (2022–2024), the team conducted extensive stakeholder engagement and developed a novel approach that links long- and short-term power systems models. Additionally, the team developed national grid-scale planning tools and practices necessary to address those interregional transmission needs. The NTP Study, including six chapters and an executive summary, was released in October 2024.

Transmission Scenarios

The NTP Study modeled and analyzed nearly 100 future transmission scenarios with a range of economic, reliability, and resilience conditions. These transmission options are not typically considered in current planning practices and can inform future planning processes. View one of the scenarios below and click to access all the scenarios. Analysis of the transmission scenarios can be found in the NTP Study's Chapter 2: Long-Term U.S. Planning Scenarios.

To download the data, visit the National Transmission Planning Study OpenEI page. If you have trouble accessing the data, contact Anne Hamilton.

Interregional Renewable Energy Zones

As part of the NTP Study, NREL conducted other analyses and developed tools that led to additional interregional planning studies, reports, and white papers. That includes two NREL technical reports on interregional renewable energy zones and barriers and opportunities for interregional transmission (listed below).

NREL studied the economics of long-distance, high-voltage transmission lines that are anchored to interregional renewable energy zones, or areas with very high concentrations of the lowest-cost developable renewable energy potential. The report, Interregional Renewable Energy Zones, seeks to:

1. Bridge the Gap: The analysis acts as a bridge between the technical modeling in the NTP Study’s national transmission scenarios and the practical decision-making processes at the state and regional levels. By aligning with national results, an interregional renewable energy zones corridor becomes a tangible example of achieving the benefits outlined in the national analysis.

2. Inform State Decision-Making: The study offers a preliminary analysis to assist state decision makers in determining whether to delve into more detailed examinations of relevant interregional renewable energy zones corridors. While this report may not encompass all case-specific details influencing transmission projects, it provides a foundation. If a corridor examined here showcases a high benefit-to-cost ratio primarily based on energy cost savings, further studies can expand the economic analysis to include local factors.

Barriers and Opportunities for Interregional Transmission

NREL examined issues that prevent existing transmission facilities from delivering maximum potential value and developed a suite of options that power system stakeholders can pursue to overcome those challenges. The report, Barriers and Opportunities to Realize the System Value of Interregional Transmission, groups barriers and opportunities for interregional transmission among all regions, between non-market or a mix of market and non-market areas, and between market areas.

NREL also identified transformative actions that could be applied to all regions to increase the value of interregional transmission. Together, the suite of strategies can help improve the efficiency and efficacy of today’s transmission system, increase grid reliability, and lead to cost savings that are then passed onto customers.

In the News

NREL’s contributions to the NTP Study are featured in the news. Read some of the recent articles and publications that highlight the study.

National Transmission Analysis Maps the Next Chapter of U.S. Grid Evolution, NREL News (2024)

A Look at the Future of Transmission: Getting Clean Electrons to Where They Need To Be, NREL News (2024)

How to Realize the Maximum Value of Interregional Transmission, NREL News (2024)

Can We Connect Renewable Energy Hubs With Electricity Consumption Hubs? NREL News (2024)

Analysis Details Scenarios for Interregional Renewable Energy Zones, American Public Power Association (2024)

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