Spurred by the widespread adoption of clean energy goals by many U.S. states and businesses — and now the Biden administration’s goal of 100 percent clean electricity by 2035 and net-zero emissions across the economy by 2050— the need for wide-scale transmission infrastructure in the United States is clear. In fall 2020, ESIG convened more than 50 U.S. and international electricity experts to refine a conceptual design for a national macro grid, key infrastructure that will allow the sharing of renewable energy between states and regions, making the decarbonization of the electricity system more rapid, reliable, and affordable.
A decade of energy system studies of how to decarbonize the U.S. electricity system and economy have found that significant transmission expansion is essential to realize effective low-carbon energy systems at lowest cost. Since many of the richest wind and solar resources are located far from the urban load centers where most of the country’s energy is consumed, the nation’s transmission infrastructure must at least double to accommodate the exponential growth of wind and solar that will accompany decarbonization. Without the addition of significant multi-regional transmission, system planners will need to overbuild local renewable resources in order to manage weather patterns and meet demand, resulting in extreme curtailment of local wind and solar resources, even if high levels of storage capacity are available, and carrying a high price tag.
Interregional transmission dramatically lowers the cost of achieving 100 percent clean electricity by reducing the amount of wind, solar, storage, and other capacity that must be built. This white paper reviews key research studies that assessed different pathways to achieving a low-carbon electricity grid, and presents the three components of the ESIG macro grid concept:
National transmission planning: The United States should establish a national transmission planning authority and initiate an ongoing national transmission planning process.
Renewable energy zones: Apart from energy efficiency, wind and solar energy are currently the lowest-cost sources of zero-carbon energy. The United States should designate renewable energy zones for large-scale wind and solar resource development and build large-scale transmission to those regions to expedite coordinated generation and transmission expansion.
Macro grid concept: The United States should develop and implement a national transmission network (the macro grid) of multi-regional high-voltage transmission that unites the country’s power systems.
The white paper outlines the characteristics of a well-designed macro grid, describes its three stages of development, and offers clear recommendations to guide a diverse group of stakeholders in designing and building an interregional macro grid for the United States.
The full Transmission Planning for 100% Clean Electricity white paper can be downloaded below.