other technologies through 2030, has estimated that the 20 percent wind scenario would result in an increase in net present value (NPV) total electricity-sector costs of $43 billion (in 2006 dollars) over the no-new-wind case.
Overall, increases in wind power generation costs (capital and operation and maintenance expenses) are partially offset by lower capital, operation and maintenance, and fuel costs for other electricity sources (DOE, 2008a). The impact on the energy mix is largest for natural gas, with the 20 percent wind scenario displacing about 50 percent of electricity-utility natural gas consumption (DOE, 2008a). The need for imported liquefied natural gas would also be greatly reduced. However, maintaining electricity system reliability would require additional capacity from natural gas combustion turbines, which can respond quickly to low-wind conditions.
The total wind power capital cost under this scenario is $236 billion NPV, and the total operation and maintenance cost is $51 billion NPV. Though many studies have shown the feasibility of incorporating significant amounts of wind power into the electricity grid (Zavadil et al., 2004; GE Energy Consulting, 2005; DeMeo et al., 2005; UWIG, 2006; Parsons et al., 2006), integrating 20 percent wind power into the electricity system would require significant investments in the electric grid and other parts of the system. The DOE study estimates the cost of such an expansion of transmission capabilities at $23 billion, though it recognizes the significant barriers to installing new transmission in general. Separately, American Electric Power (AEP) developed a conceptual interstate transmission plan for integrating in excess of 300 GW from wind power and reducing existing transmission bottlenecks. AEP estimates that such a system would include 19,000 miles of new high-voltage (765-kV) transmission corridors and would require investments on the order of $60 billion (AEP, 2007).
The 20 percent wind scenario study has spurred related studies focused specifically on regional integration of a large fraction of intermittent renewable electricity. Ongoing large-scale studies on the regional integration of 20 percent and more of renewables into the electricity system include the Eastern Wind Integration and Transmission Study/Joint Coordinated System Planning Study (described at www.jcspstudy.org/) and the Western Wind and Solar Integration Study (JCSP, 2009; described at wind.nrel.gov/public/WWIS/). The JCSP study, as with the DOE’s 20% wind energy study, included multiple stakeholders in a collaborative that held numerous public workshop meetings. JCSP (2009) looked at two scenarios: one a reference case with 5 percent market penetration by wind and the second with 20 percent wind. For the 5 percent wind scenario, the study estimated