NREL study highlights challenges of 20 percent wind by 2024

The study focuses on the U.S. Eastern Interconnection electrical system and says that 20 percent wind energy by 2024 is feasible, but will require substantial expansion of energy transmission systems.

The U.S. Department of Energy's (DOE) National Renewable Energy Laboratory (NREL) on Jan. 20 released the Eastern Wind Integration and Transmission Study (EWITS). This unprecedented two-and-a-half year technical study of future high-penetration wind scenarios was designed to analyze the economic, operational, and technical implications of shifting 20 percent or more of the Eastern Interconnection's electrical load to wind energy by the year 2024.

"Twenty percent wind is an ambitious goal, but this study shows that there are multiple scenarios through which it can be achieved," said David Corbus, NREL project manager for the study. "Whether we're talking about using land-based wind in the Midwest, offshore wind in the East or any combination of wind power resources, any plausible scenario requires transmission infrastructure upgrades and we need to start planning for that immediately."

The study identified operational best practices and analyzed wind resources, future wind deployment scenarios, and transmission options. Among its key findings are:

  1. The integration of 20 percent wind energy is technically feasible, but will require significant expansion of the transmission infrastructure and system operational changes in order for it to be realized
  2. Without transmission enhancements, substantial curtailment of wind generation would be required for all 20 percent wind scenarios studied
  3. The relative cost of aggressively expanding the existing transmission grid represents only a small portion of the total annualized costs in any of the scenarios studied
  4. Drawing wind energy from a larger geographic area makes it both less expensive and a more reliable energy source — increasing the geographic diversity of wind power projects in a given operating pool makes the aggregated wind power output more predictable and less variable
  5. Wind energy development is a highly cost-effective way to reduce carbon emissions — as more wind energy comes online, less energy from fossil-fuel burning plants is required, reducing greenhouse gas emissions
  6. Carbon emissions are reduced by similar amounts in all scenarios, indicating that transmission helps to optimize the electrical system and does not result in coal power being shipped from the Midwest to New England States
  7. Reduced fossil fuel expenditures more than pay for the increased costs of additional transmission in all high wind scenarios.
"To put the scale of this study in perspective, consider that just over 70 percent of the U.S. population gets its power from the Eastern Interconnect. Incorporating high amounts of wind power in the Eastern grid goes a long way towards clean power for the whole country," said Corbus. "We can bring more wind power online, but if we don't have the proper infrastructure to move that power around, it's like buying a hybrid car and leaving it in the garage."

The EWITS Executive Summary and the full study can be downloaded for free at and includes exploration of wind energy development scenarios, approximate costs for each scenario, transmission system potential changes, and other data.