New National Wind Potential Estimates for 

Modern and Near-Future Turbine Technologies

J.O. Roberts • National Renewable Energy Laboratory (NREL) • Golden, Colorado

NREL is a national laboratory of the U.S. Department of Energy, Office of Energy Efficiency and Renewable Energy, operated by the Alliance for Sustainable Energy, LLC.

2014 WIND PROJECT SITING SEMINAR | January 2930, 2014| New Orleans, LA | NREL/PO-5000-60979

The Southeast Region: An Example

Figure 4 shows areas with a GCF of > 40% (net capacity factor ~34% 

with15% losses) assuming Nordex N117-2.4 at 140 m hub height. The 

taller hub heights in this assumption are mainly due to many areas in the 

region having very high wind shear, which increases the cost 

effectiveness of taller towers and the available wind resource. 

Siting Considerations, New Dataset Advantages, and the Need for Outreach

• Siting considerations for new areas:

• There is a high potential for turbines to be deployed in states and communities where wind has never been considered or 

discussed on a utility scale. 

• The potential for interactions with new species of wildlife is likely and will necessitate new siting considerations.

• The current Federal Aviation Administration’s permitting process for turbine tip heights greater than 500 feet is currently limiting 

tower turbine heights in the United States and uncertainty in approval times is a driving factor behind the use of shorter towers.

• Key dataset improvements:

• The approach used to generate the data herein utilizes hourly wind speed data to compute hourly turbine production for each 200-

m cell. This increases the accuracy of the model used to determine the levelized cost of energy (LCOE) of new potential projects.

• The new data process uses modern large rotor machines selected for each International Electrotechnical Commission wind 

regime using altitude-adjusted wind speed to compute annual energy production.

• Future and ongoing analysis:

• NREL to release new CF maps and capacity curves for each state to engage stakeholders

• This data is being utilized in the upcoming DOE wind vision study to reflect the increased potential in lower wind speed regimes

• Ongoing research will be conducted to reduce LCOE specifically through taller hub heights.

• Other advantages for deployment: 

• This new potential for deploying wind in previously undevelopable areas lessens the requirement for additional transmission for 

deployments of equivalent LCOE by allowing siting of wind projects closer to load centers.

Image by Donna Heimiller, NREL

Areas of New Potential Turbine Deployment

Figure 3. Buffalo Mountain Wind Farm near Oak Ridge, Tennessee, the only operating commercial 

wind farm in the southeastern United States. Photo by Owen Roberts, NREL

Figure 1. This image 

shows areas with a 

Gross Capacity 

Factor (GCF) of > 

30% assuming a 2-

MW 80-m rotor 

turbine at an 80-m 

hub height. These 

estimates were used 

in the original 2008 

20% Wind by 2030

U.S. Department of 

Energy (DOE)/NREL 

report assuming the 

aforementioned 

technology for all 

locations and wind 

regimes. 

Image by Donna Heimiller, NREL

Figure 2. This image 

shows new areas with 

GCF > 30% assuming 

modern GE 1.6100, 

82.5, and 77-m rotors 

depending on the 

altitude-adjusted 

annual average wind 

speed. The shading 

shows raw 

developable area at a 

resolution of roughly 

400 km2 with the 

intensity of shading 

being proportional to 

the density of 

developable area 

within each cell.

Capacity factor is not necessarily the appropriate 

measure of project viability, but these images serve 

as an illustration of the new areas that may be more 

cost effective for wind energy deployment as turbine 

technology accelerates or energy prices increase. 

The wind industry has already begun deploying 

utility-scale projects, which utilize large rotors, at 

sites with hub-height annual average wind speeds 

as low as 6.0 m/s. Newer machines with even larger 

rotors are currently being deployed cost effectively 

at lower wind speed sites. As areas of higher wind 

resource are developed and constraints such as 

transmission capacity decrease the total potential 

developable area at higher wind speed sites, lower 

wind speed sites will become more attractive for 

development. Turbine technology is likely to follow 

this trend, but much development is needed to 

lower the costs of taller towers and longer blades. 

Image by Donna Heimiller, NREL

Acceleration in turbine technology in the past ~5 years has created much higher capacity factors using much larger rotors per MW. Assuming the same capacity factor threshold, the results of 

applying modern turbine technology to the same wind data results in large increases in raw area that may be suitable for deployment. The figures below illustrate the magnitude of this change. NREL's 

contribution to this poster was funded by the Wind and Water Power Program, Office of Energy Efficiency and Renewable Energy of the U.S. Department of Energy under Contract No. DE-AC02-

05CH11231.

Figure 3 shows new areas with a GCF of > 30% when 

compared with previous NREL estimates. Total new 

potential in deployable area has a 50.6% increase over 

previous estimates. The total new capacity potential is 

3,907 GW of installed capacity assuming 3 MW/km2. 

Machines with taller hub heights and larger rotors 

specifically designed for lower average and appropriate 

extreme wind speeds may increase this overall potential. 

The shading shows raw developable area at a resolution 

of roughly 400 km2 with the intensity of shading being 

proportional to the density of developable area within 

each cell. 

The total potential for the southeastern states using sites with a > 40% CF is 134 GW of 

installed capacity (Louisiana: > 50GW; Missouri and Tennessee: > 25 GW) with the 

assumptions from Figure 1 for hub height and the capacity factor from Figure 4. These 

estimates assume 2.6 MW per square kilometer; machines with larger rotors specifically 

designed for lower average and extreme wind speeds may increase this potential. The 

uncertainty in the data at 140 m above ground level is high as few validation points exist 

currently. However, wind project development in some of these areas is ongoing as proposed 

projects near construction.

Image by Donna Heimiller, NREL

Figure 1 Figure 2

Figure 3

Figure 4