The ‘Eastern Wind Integration and Transmission Study’ was launched in 2008 to examine what effect "20% to 30% wind energy penetration" would have on the Eastern Interconnect electricity network, which supplies 70% of the US’ population’s power needs.
The study found the ambitious target was possible. To have a chance of reaching this figure, the NREL believes billions must be spent on building wind farms on land and offshore together with around 22,000 miles of new power lines.
Reaching the 20% penetration target in the eastern electric grid by 2024 would require a substatial increase in wind generation in the region. This would equate to a 10-fold increase on current capacity, the study said.
Speaking about the report, NREL project manager David Corbus said: "20% wind is an ambitious goal, but this study shows that there are multiple scenarios through which it can be achieved.
"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."
Key findings from the report include:
• High penetrations of wind generation—20% to 30% of the electrical energy requirements of the Eastern Interconnection—are technically feasible with significant expansion of the transmission infrastructure.
• New transmission will be required for all the future wind scenarios in the Eastern Interconnection, including the Reference Case. Planning for this transmission, then, is imperative because it takes longer to build new transmission capacity than it does to build new wind plants.
• Without transmission enhancements, substantial curtailment (shutting down) of wind generation would be required for all the 20% scenarios.
• Interconnection-wide costs for integrating large amounts of wind generation are manageable with large regional operating pools and significant market, tariff, and operational changes.
• Transmission helps reduce the impacts of the variability of the wind, which reduces wind integration costs, increases reliability of the electrical grid, and helps make more efficient use of the available generation resources. Although costs for aggressive expansions of the existing grid are significant, they make up a relatively small portion of the total annualized costs in any of the scenarios studied. 14
• Carbon emission reductions in the three 20% wind scenarios do not vary by much, indicating that wind displaces coal in all scenarios and that coal generation is not significantly exported from the Midwest to the eastern United States; carbon emissions are reduced at an increased rate in the 30% wind scenario as more gas generation is used to accommodate wind variability. Wind generation displaces carbon-based fuels, directly reducing carbon dioxide (CO2) emissions. Emissions continue to decline as more wind is added to the supply picture. Increasing the cost of carbon in the analysis results in higher total production costs.