Macro Grid Initiative

The Macro Grid Initiative promotes investment in a 21st century transmission network that will drive job growth, reduce pollution, and save American consumers money.

A transmission worker looks up at the night sky and transmission lines above him


Antiquated transmission infrastructure and a balkanized electric grid are limiting America’s ability to meet changing demands on the electric system.

Investment in more interregional transmission through a U.S. Macro Grid that better connects our largest population centers with our lowest-cost renewable energy resources will enhance grid reliability and resiliency, save consumers billions of dollars, deliver significant job creation, and dramatically reduce carbon emissions. 

There are many polarizing issues dividing America today, but support for reliable electricity is not among them. No one is in favor of power outages, and no one should be left in the dark.

Ted Thomas

Former Arkansas PSC Chair

Power system operators confirm that a larger geographic footprint for the nation’s power grids decreases variability in energy supply and demand while also improving system performance. As extreme weather events increase in frequency and severity, more interregional transmission lines will be critical to prevent deadly power outages and grid failures. More interregional lines would also help enable the transfer of the lowest-cost power during normal operating conditions.

A map of the U.S. highlighting the lack of existing transmission capacity
Based on the EPA Integrated Planning Model, the analysis of existing electricity transmission transfer capacity between adjacent FERC Order 1000 planning regions. Percent [%] reflects the interconnection capacity of connected regions as a percentage of the peak load of the larger region. Arrow colors indicate levels, red ≤ 5%, yellow 6-14%, green ≥ 15%

The research is clear: the U.S. urgently needs a macro grid.

  • 1 B The U.S could reduce emissions by 1 billion tons annually by 2030 if transmission expansion is more than doubled.

  • $ 1 B ERCOT and the Southeast could have saved nearly $1 billion for each additional gigawatt of transmission ties.

  • $ 40 B The U.S. would save more than $40 billion a year by building a nationally connected high-voltage transmission network.

  • 200000 Additional transmission could have kept the lights on in 200,000 Texas homes during Winter Storm Uri in February 2021.

It's not a partisan issue because everybody needs access to power, and transmission is essential for every energy source.

Rep. Scott Peters


Vision Statement
A transmission tower at sunset

Vision Statement

Macro Grid Initiative

“Expanding and upgrading the nation’s transmission network will deliver jobs and economic development, a cleaner environment, and lower costs for consumers.”

The vision of the Macro Grid Initiative is right on point by aligning transmission development with economic, environmental, and consumer outcomes.

Devin Hartman

Director of Energy and Environmental Policy, R Street Institute

Latest Reports

Latest Reports

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Energy Assurance Depends on a Resilient Transmission Grid

  • Fact Sheets
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Billions in Benefits: A Path for Expanding Transmission Between MISO and PJM

  • Reports
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The Need for Intertie Optimization: Reducing Customer Costs, Improving Grid Resilience, and Encouraging Interregional Transmission

  • Reports
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Newsletter Transmission Resources

Transmission Resources

ACORE’s Macro Grid Initiative, coalition partners, ally groups, and academic and government institutions have developed groundbreaking resources highlighting the benefits of expanding and upgrading the nation’s transmission grid, as well as the regulatory challenges that are blocking progress to those upgrades. These resources, organized by topic, are listed below.

Fact Sheets

Upgrading and Expanding the U.S. Transmission Grid

Energy Assurance Depends on a Resilient Transmission Grid

Benefits of Transmission

Upgrading And Expanding High-Voltage Transmission Creates Jobs

Transmission and Climate Change

The Benefits of High-Voltage Transmission In A Global Economy

Benefits of a Macro or Nationally Connected Grid

Interconnections Seam Study – NREL (September 2021)

Transmission Planning for 100% Clean Electricity – ESIG (February 2021)

The Value of Inter-Regional Coordination and Transmission in Decarbonizing the US Electricity System – MIT (January 2021)

Net-Zero America: Potential Pathways, Infrastructure, and Impacts – Princeton University (December 2020)

Grid Vision: The Electric Highway to a 21st Century Economy – American Wind Energy Association (May 2019)

North American Supergrid: Transforming Electricity Transmission – Climate Institute (2017)

Future Cost-Competitive Electricity Systems and Their Impact on US CO2 Emissions – NOAA, University of Colorado, Boulder (January 2016)

International Competitiveness

Electricity Transmission is Key to Unlock the Full Potential of the Inflation Reduction Act – Princeton University (September 2022)

Macro Grids in the Mainstream: An International Survey of Plans and Progress – Iowa State University, ACEG, ACORE (November 2020)

Interregional Transmission

Interregional Transmission for Resilience: Using Regional Diversity to Prioritize Additional Interregional Transmission – ESIG (June 2024)

Barriers and Opportunities To Realize the System Value of Interregional Transmission – NREL (June 2024)

Billions in Benefits: A Path for Expanding Transmission Between MISO and PJM – Grid Strategies, ACORE (November 2023)

National Transmission Needs Study – U.S. DOE (October 2023)

The Need for Intertie Optimization: Reducing Customer Costs, Improving Grid Resilience, and Encouraging Interregional Transmission – Brattle, Invenergy, Grid United, ACORE, et al. (October 2023)

The Operational and Market Benefits of HVDC to System Operators – Brattle, DNV, Grid United, ACORE, et al. (September 2023)

The Value of Transmission During Winter Storm Elliott – Grid Strategies, ACORE (February 2023)

The Latest Market Data Show that the Potential Savings of New Electric Transmission was Higher Last Year than at Any Point in the Last Decade – Lawrence Berkeley National Laboratory (February 2023)

HVDC Transmission: A National Security and Energy Resilience Imperative – Converge Strategies, Invenergy Transmission (December 2022)

Economic, Reliability, and Resiliency Benefits of Interregional Transmission Capacity – General Electric International, NRDC (October 2022)

Potential Customer Benefits of Interregional Transmission – General Electric International, ACORE (November 2021)

Transmission Makes the Power System Resilient to Extreme Weather – Grid Strategies, ACORE (July 2021)

Consumer, Employment, and Environmental Benefits of Electricity Transmission Expansion in the Eastern U.S. – Vibrant Clean Energy, Grid Strategies, ACEG (October 2020)

Eastern Interconnection Planning Collaborative – DOE (December 2011)

Offshore Transmission

Making Offshore Wind Transmission Work for Communities – Regional Plan Association, Karp Strategies (June 2023)

The Benefit and Urgency of Planned Offshore Transmission: Reducing the Costs of and Barriers to Achieving U.S. Clean Energy Goals – Brattle, NRDC, ACORE, et al. (January 2023)

The Benefit and Cost of Preserving the Option to Create a Meshed Offshore Grid for New York – Brattle, NYSERDA (November 2021)

Offshore Wind Transmission – BNOW, Grid Strategies (October 2020)

Paying for Transmission

Just & Reasonable? Transmission Upgrades Charged to Interconnecting Generators Are Delivering System-Wide Benefits – ICF Resources, ACORE (September 2021)

Investment Tax Credit for Regionally Significant Transmission Lines: A Description and Analysis – Grid Strategies, ACORE (May 2021)

Transmission Projects Ready to Go: Plugging into America’s Untapped Renewable Resources – Grid Strategies, ACEG (April 2021)

Disconnected: The Need for a New Generator Interconnection Policy – Grid Strategies, ACEG (January 2021)

Permitting Transmission

Evidence-Based Recommendations for Overcoming Barriers to Federal Transmission Permitting – Niskanen Center and Clean Air Task Force (April 2024)

NEPA Litigation Over Large Energy and Transport Infrastructure Projects – Stanford University (October 2023)

Transmission Planning

Transmission Planning for PJM’s Future Load and Generation Version 1 – Grid Strategies, David Gardiner and Associates, ACEG (June 2024)

Transmission Expansion for National Defense – Association of Defense Communities and Converge Strategies (April 2024)

Transmission Planning and Development Regional Report Card – Grid Strategies, ACEG (June 2023)

Enabling Low-Cost Clean Energy and Reliable Service Through Better Transmission Benefits Analysis: A Case Study of MISO’s Long Range Transmission Planning – Grid Strategies, ACORE (August 2022)

Multi-Value Transmission Planning for a Clean Energy Future – ESIG (June 2022)

Transmission Planning for the 21st Century: Proven Practices that Increase Value and Reduce Costs – Brattle, Grid Strategies, ACORE, et al. (October 2021)

How Are We Going to Build All That Clean Energy Infrastructure? – Niskanen Center, CATF (August 2021)

How Transmission Planning & Cost Allocation Processes Are Inhibiting Wind & Solar Development in SPP, MISO, & PJM – Concentric Energy Advisors, ACORE, et al. (March 2021)

Planning For The Future: FERC’s Opportunity To Spur More Cost-Effective Transmission Infrastructure – Grid Strategies, ACEG, ACORE (January 2021)

Report On Barriers and Opportunities for High Voltage Transmission – FERC (June 2020)

Upgrading Transmission Within the Existing Grid Footprint

Pathways to Commercial Liftoff: Innovative Grid Deployment – U.S. DOE (April 2024)

The 2035 Report: Reconductoring With Advanced Conductors Can Accelerate the Rapid Transmission Expansion Required for a Clean Grid – University of California Berkeley and GridLab (April 2024)

GETting Interconnected in PJM – RMI (February 2024)

Accelerating Transmission Expansion by Using Advanced Conductors in Existing Right-of-Way – University of California, Berkeley (February 2024)

Transmission Congestion Costs Rise Again in U.S. RTOs – Grid Strategies (July 2023)

Building a Better Grid: How Grid-Enhancing Technologies Complement Transmission Buildouts – Brattle, WATT Coalition (April 2023)

Advanced Conductors on Existing Transmission Corridors to Accelerate Low Cost Decarbonization – Grid Strategies, CTC Global, ACORE, et al. (March 2022)

Grid-Enhancing Technologies: A Case Study on Ratepayer Impact – U.S. DOE (February 2022)

Unlocking the Queue with Grid-Enhancing Technologies – Brattle, WATT Coalition (February 2021)