National Renewable Energy Laboratory 

Innovation for Our Energy Future 

A national laboratory of the U.S. Department of Energy

Office of Energy Efficiency & Renewable Energy

NREL is operated by Midwest Research Institute ● Battelle Contract No. DE-AC36-99-GO10337 

Necessity and Requirements of a 

Collaborative Effort to Develop a 

Large Wind Turbine Blade Test 

Facility in North America 

J. Cotrell, W. Musial, and S. Hughes 

Technical Report 

NREL/TP-500-38044 

May 2006 
Necessity and Requirements of a 

Collaborative Effort to Develop a 

Large Wind Turbine Blade Test 

Facility in North America 

J. Cotrell, W. Musial, and S. Hughes 

Prepared under Task No. WER6 3301 

Technical Report 

NREL/TP-500-38044 

May 2006 

National Renewable Energy Laboratory 

1617 Cole Boulevard, Golden, Colorado 80401-3393 

303-275-3000 • www.nrel.gov 

Operated for the U.S. Department of Energy 

Office of Energy Efficiency and Renewable Energy 

by Midwest Research Institute • Battelle 

Contract No. DE-AC36-99-GO10337
NOTICE

This report was prepared as an account of work sponsored by an agency of the United States government. 

Neither the United States government nor any agency thereof, nor any of their employees, makes any 

warranty, express or implied, or assumes any legal liability or responsibility for the accuracy, completeness, or 

usefulness of any information, apparatus, product, or process disclosed, or represents that its use would not 

infringe privately owned rights. Reference herein to any specific commercial product, process, or service by 

trade name, trademark, manufacturer, or otherwise does not necessarily constitute or imply its endorsement, 

recommendation, or favoring by the United States government or any agency thereof. The views and 

opinions of authors expressed herein do not necessarily state or reflect those of the United States 

government or any agency thereof. 

Available electronically at http://www.osti.gov/bridge

Available for a processing fee to U.S. Department of Energy 

and its contractors, in paper, from: 

U.S. Department of Energy 

Office of Scientific and Technical Information 

P.O. Box 62 

Oak Ridge, TN 37831-0062 

phone: 865.576.8401 

fax: 865.576.5728 

email: mailto:reports@adonis.osti.gov

Available for sale to the public, in paper, from: 

U.S. Department of Commerce 

National Technical Information Service 

5285 Port Royal Road 

Springfield, VA 22161 

phone: 800.553.6847 

fax: 703.605.6900 

email: orders@ntis.fedworld.gov

online ordering: http://www.ntis.gov/ordering.htm

Printed on paper containing at least 50% wastepaper, including 20% postconsumer waste
iii

Executive Summary

Introduction

The wind power industry in North America has an immediate need for larger blade test facilities to ensure 

the survival of the industry. Blade testing is necessary to meet certification and investor requirements and 

is critical to achieving the reliability and blade life needed for the wind turbine industry to succeed. The 

U.S. Department of Energy’s (DOE’s) Wind Program is exploring options for collaborating with 

government, private, or academic entities in a partnership to build larger blade test facilities in North 

America capable of testing blades up to at least 70 m in length. 

The National Renewable Energy Laboratory (NREL) prepared this report for DOE to describe the 

immediate need to pursue larger blade test facilities in North America, categorize the numerous 

prospective partners for a North American collaboration, and document the requirements for a North 

American test facility. 

The Problem 

Rapid growth in wind turbine size over the past two decades has outstripped the capacity of blade test 

facilities at NREL, hindering the North American wind turbine and component manufacturers’ 

opportunities to participate in what is predicted to be more than $80 billion of annual global business by 

2020. There are significant barriers to North American wind turbine and component manufacturers 

independently developing their own facilities, including: 

• Construction of a blade test facility capable of fatigue testing 70-m blades requires a large initial 

capital investment of at least $5 million to $11 million. 

• Fatigue testing requires a dedicated staff of at least four people. 

• The costs to construct and operate a large blade test facility make the return on investment 

unattractive for private testing companies. 

• The inconsistency of the production tax credit has resulted in an uncertain U.S. market for wind 

turbines, making the investment in a large facility risky for the wind industry and private testing 

companies. 

• Most North American blade and turbine manufacturers have insufficient testing demand to fully 

occupy their own, company-specific, large blade test facility, and most other manufacturers would 

deem it unacceptable to rely on a competitor to provide this service. 

• A private facility does not provide third party objectivity required for certification and validation 

testing. 

The Solution

The preferred solution is for a neutral third party like DOE to facilitate the development of a joint industry 

collaboration that can provide the needed facilities to all members of the wind industry on a fee-forservice basis. The exact nature of the collaboration may vary, but the objective would be to provide fair 

access to the needed services. Primary benefits resulting from construction of a large blade test facility are 

to: 

• Directly support the President’s Advanced Energy Initiative goal and Departmental priorities of 

expanding access to wind energy through technology

• Allow wind turbine manufactures to meet certification and investor requirements for wind turbine 

blades
iv

• Provide a development path for new products and technologies used in large land-based and 

offshore wind turbines

• Help understand the failure mechanisms for technologies used to manufacture very large wind 

turbine blades, thereby reducing the risk and cost of manufacturing, servicing, and warranting 

large turbines and reducing the cost of electricity from wind turbines

• Maintain the competitiveness of U.S. wind turbine manufacturers with European companies and 

help ensure U.S. participation in what is predicted to be more than $80 billion of annual global 

business by 2020 

• Provide an economic magnet for similar businesses to relocate to a particular region. 

Current Program funding levels and the impact of congressionally directed activities at this time require 

that development of a facility be conducted with significant industry participation and cost share. A 

number of international, federal, academic, state, municipal, and private entities may be interested in 

collaborating with DOE on a blade test facility in North America. The primary elements required for a 

successful blade test facility are land and a building near a seaport, two or more test stands, test equipment, 

and trained facility staff. DOE may be able to provide some of these items and offer some commitment to 

testing. NREL, a DOE laboratory operated by the Midwest Research Institute and Battelle, is well-suited 

to provide the technical expertise and/or staff to develop and operate the facility. Additional funds, inkind services, and testing commitments are required from other collaboration partners for a successful 

effort. 
v

Table of Contents

Executive Summary ..................................................................................................................................... iii 

Table of Contents...........................................................................................................................................v 

List of Figures.............................................................................................................................................. vi 

List of Tables ............................................................................................................................................... vi 

1 Introduction............................................................................................................................................1 

1.1 Report Objectives...........................................................................................................................1 

1.2 Scope of the Report........................................................................................................................1 

2 Motivations for Pursuing a Large Blade Test Facility Collaboration in North America.......................2 

2.1 Testing Trends................................................................................................................................2 

2.1.1 Increased Emphasis on Blade Testing....................................................................................2 

2.1.2 Larger Turbines......................................................................................................................3 

2.2 North American Industries Have No Large Blade Test Facility Access .......................................4 

2.2.1 NWTC Blade Test Facility Limitations.................................................................................5 

2.2.2 Barriers to Construction of New Test Facilities in North America without Government 

Assistance...............................................................................................................................7 

2.2.3 Barriers to Using European Blade Test Facilities..................................................................7 

3 Requirements and Costs of a Large Blade Test Facility........................................................................9 

3.1 Testing Capabilities......................................................................................................................10 

3.1.1 Basic Testing........................................................................................................................10 

3.1.2 Multiple Test Stands ............................................................................................................11 

3.1.3 100-m Blade Test Facility....................................................................................................11 

3.2 Building Requirements ................................................................................................................12 

3.3 Revenue Model ............................................................................................................................13 

4 Collaboration Structure ........................................................................................................................15 

4.1 Collaboration Partners..................................................................................................................15 

4.2 Partner Contributions...................................................................................................................15 

4.2.1 NREL Contributions............................................................................................................16 

4.2.2 DOE Contributions ..............................................................................................................17 

4.2.3 Federal, State, Municipal, or Academic Contributions........................................................17 

4.2.4 Industry Contributions .........................................................................................................17 

4.3 Ownership and Operating Models for a Collaborative Facility...................................................18 

4.3.1 Ownership of European Test Facilities................................................................................18 

4.3.2 Ownership and Operation of a Collaborative Facility in North America ............................18 

5 Summary ..............................................................................................................................................21 

Appendix 1: Overview of European Blade Test Facilities...........................................................................23 

Appendix 2: Detailed Requirements for a Large Blade Test Facility..........................................................28 

Appendix 3: Approximate Costs for Large Blade Test Facility Options.....................................................30 

Appendix 4: Approximate Net Revenue for a Large Blade Test Facility....................................................31 
vi

List of Figures

Figure 1: Design lifetime requirements of industries comparable to the wind industry................................3 

Figure 2: Blade and NWTC test facility growth from 1988 to 2006 .............................................................4 

Figure 3: Maximum blade length capacities for blade test facilities worldwide ...........................................5 

Figure 4: 50-m blade test stand outside of the NWTC blade test facility......................................................6 

Figure 5: European blade test facility locations and capacities.....................................................................8 

Figure 6: Bell crank system (painted yellow) used in the 34-m NWTC Blade Test Facility for edgewise 

fatigue testing................................................................................................................................11 

Figure 7: Ultimate strength of the blade root relative to the blade length ...................................................12 

Figure 8: Installation of the NWTC B-REX fatigue testing system ............................................................17 

Figure 9: European blade test facility locations and capacities...................................................................23 

Figure 10: Maximum blade length capacities for blade test facilities worldwide .......................................24 

Figure 11: The WMC blade test facility ......................................................................................................26 

Figure 12: LM Glasfiber blade test facility..................................................................................................26 

Figure 13: NaREC blade test facility ...........................................................................................................27 

List of Tables

Table 1: Key Facility Requirements for a Large Blade Test Facility ............................................................9 

Table 2: Summary of Cost Estimates for a Large Blade Test Facility ($ in Thousands) ............................10 

Table 3: Approximate Maximum Annual Net Revenue from a Blade Test Facility ...................................14 

Table 4: Key Requirements for a Blade Test Facility and Possible Contributions of Collaboration 

Members........................................................................................................................................16 

Table 5: European Ownership Models.........................................................................................................18 

Table 6: Summary of North American Blade Test Facility Collaboration Ownership Models...................19 

Table 7: Overview of European Blade Test Facilities.................................................................................25 

Table 8: Requirements for a Large Blade Test Facility ...............................................................................28 

Table 9: Approximate Capital Costs for Blade Test Facilities ....................................................................30 

Table 10: Approximate Revenues from Blade Test Facilities.....................................................................31 
1

 

1 Introduction 

All new designs of large wind turbine blades must be static and fatigue tested to verify their ability to 

withstand operating loads. The tests reduce financial risk and are necessary to meet certification and 

investor requirements. The U.S. Department of Energy’s (DOE’s) National Renewable Energy Laboratory 

(NREL) operates the only blade test facility in North America capable of performing full-scale testing of 

megawatt-size wind turbine blades. Recent increases in turbine size have outstripped the capabilities of 

this blade test facility. 

In 2001, the DOE Wind Program began plans to construct an 8-MW dynamometer and 70-m blade test 

facilities at the National Wind Technology Center (NWTC) to support the Wind Program’s public/private 

partnerships to develop larger turbines. The project passed the first set of DOE facility approvals, but 

progress stopped before the next step (a conceptual design report) was initiated. The facility was not 

included in the DOE Office of Energy Efficiency and Renewable Energy's FY06 Budget Request to 

Congress, and full DOE funding to build larger test facilities is not expected to become available. 

The DOE Wind Program is exploring options for collaborating with government, private, or academic 

entities in a public/private partnership to build larger blade test facilities. The Program’s motivation in the 

collaboration is to provide testing capabilities of sufficient size and availability to support the U.S. wind 

industry’s growth and development, and the deployment of large land-based and offshore wind turbines. 

This effort directly supports the President’s National Energy Policy and Advanced Energy Initiative and 

Departmental priorities for increasing the viability and deployment of renewable energy.1

1.1 Report Objectives 

The objectives of this strategy paper are to: 

1. Summarize and consolidate the DOE Wind Program’s efforts and ideas about pursuing a blade test 

facility collaboration 

2. Examine the need for non-private involvement in a collaboration to build larger blade test facilities 

3. Explore the size, cost, and technical requirements for a blade test facility necessary to meet North 

American wind industry needs 

4. Examine potential ownership and operational options for a collaborative blade test facility. 

1.2 Scope of the Report 

Collaboration could take many different forms with a variety of partners. The scope of this paper is 

limited to blade test facilities, one of the wind industry’s immediate needs. However, a blade test facility 

may be part of a larger facility that supports certification and permitting assistance, drivetrain testing, 

land-based and offshore wind turbine testing, wave energy testing, marine current testing, environmental 

testing, and acoustic testing. 

1 Wind Energy Program Multi-Year Program Plan 2007-2011 Revision 3.09 
2

2 Motivations for Pursuing a Large Blade Test Facility Collaboration in North America 

This section examines the motivations for pursuing a large blade test facility in North America. The 

important points described in this section are summarized below. 

• Rapid increases in turbine size have outstripped the capabilities of NREL’s blade test facility at 

the NWTC. 

• Full DOE funding to build larger test facilities is not expected to become available in the near 

future. 

• The size of offshore turbines is expected to increase. 

• All new wind turbine blade designs must be static and fatigue tested. 

• Larger blade test facilities in North America are required to maintain and foster a competitive 

North American wind industry. 

• Blade test facilities capable of fatigue testing are too expensive for most North American wind 

industry members to construct and operate independently. 

• Europe has developed several large blade test facilities, giving European manufacturers a 

competitive edge. 

• Concerns about intellectual property, scheduling priorities, and shipping costs make the North 

American wind industry’s dependence on European test facilities problematic. 

• A number of Federal, academic, state, and municipal entities may be willing to participate in a 

blade test facility collaboration. 

2.1 Testing Trends 

Two primary factors drive the need for larger blade test facilities worldwide: 1) Blades are tested more 

thoroughly to meet new wind turbine design standards, reduce machine cost, and reduce the financial risk 

of deploying between hundreds to thousands of a particular wind turbine model; and 2) Turbine size has 

increased rapidly in the past two decades and will continue to increase as the offshore turbine industry 

develops. 

2.1.1 Increased Emphasis on Blade Testing 

Wind turbine blades are designed to withstand 20 years of high operating loads. This life is far beyond the 

service life of any large composite structures subjected to high strains (Figure 1). For this reason, 

established engineering practices and knowledge from other industries cannot be relied on to validate 

blade designs. Controlled testing in a blade test facility yields the only reliable validation of individual 

full-scale designs. 
Figure 1: Design lifetime requirements of industries comparable to the wind industry

Blades must be tested more thoroughly to meet new wind turbine design standards, reduce machine cost, 

and reduce the financial risk of deploying as many as thousands of large wind turbines. U.S. 

manufacturers have privately stated that they will not use a blade design without fatigue testing because of 

the high risk that a potential failure invites.2

 Moreover, the International Electrotechnical Commission 

(IEC), the recognized international body for standards development, requires static and modal testing of 

wind turbine blades for new design or manufacturing process changes and is expected to require fatigue 

testing by 2009. In addition, the consensus of the IEC full-scale blade test committee members is that the 

common practice of testing only one article to qualify design and production quality is a bare-minimum 

requirement. This practice is due primarily to a lack of test facilities and time-to-market requirements. A 

multiple test stand facility would provide a means to cost effectively conduct multiple tests, thereby 

greatly increasing the statistical significance and allowing further optimization of design. 

2.1.2 Larger Turbines 

Figure 2 illustrates the rapid growth in wind turbine size over the past two decades. This growth has 

historically been difficult to predict and has repeatedly exceeded manufacturer predictions. The growth 

has been driven by factors such as lower balance of station and operations and maintenance costs, access 

to increased wind speeds at higher elevations, materials and technology improvements, a better 

understanding of wind turbine loads and design, manufacturing capabilities, and the construction of large 

offshore machines. 

 

3

2

 U.S. DOE Wind and Hydropower Technologies Program FY2005 DOE Wind Program Strategic Planning Meeting; 

Washington, D.C.; February 23-24, 2005 
0

10

20

30

40

50

60

70

1985 1990 1995 2000 2005 2010

Blade Length (m)

NWTC IUF Blade Test Facility 

built for blades up to 34m

NWTC Blade Test Facility 

modified for limited testing of 

blades up to 50m

.1 MW

.5 MW

.75 MW 

3.6 MW

5 MW

1.5 MW

NWTC testing begins 

for blades up to 19m

Figure 2: Blade and NWTC test facility growth from 1988 to 2006 

The continued development of offshore turbines will motivate the trend to larger machines and will 

require construction of larger blade test facilities worldwide. More than 800 MW of offshore wind energy 

capacity operate in shallow waters off the shores of several European countries, and some of these 

countries plan a major expansion of offshore wind power. The United States has a huge offshore potential 

(currently estimated to be more than 1000 gigawatts) that provides the opportunity for offshore wind 

energy to respond to current and future U.S. energy needs. 3

Presently, the largest offshore machine is rated at 5 MW and uses a 61.5-m blade. Additionally several 

turbines in the 3.5-MW range, using blades longer than 50 m, are now commercially available. It is 

widely expected that the turbine size will increase to offset the high cost of offshore foundations and to 

take advantage of relaxed transportation size constraints offshore. As with land-based turbines, the growth 

in turbine size will be difficult to predict accurately. Nevertheless, if one extrapolates the exponential 

growth depicted in Figure 2, offshore machines could conceivably exceed 10 MW in size by 2012 as no 

technical limits exist to prevent this. 

2.2 North American Industries Have No Large Blade Test Facility Access 

A large blade test facility could serve many North American wind industry members. In addition to 

enabling larger companies to test blades, smaller companies would also have access to the facility and 

have the opportunity to develop innovative blade technologies. 

 

4

3

 Wind Energy Program Multi-Year Program Plan 2007-2011 Revision 3.09 
Currently, North American wind turbine manufacturers do not have the ability to test blades longer than 

50 m in North America. The lack of facilities in North America puts the North American wind industry at 

a competitive disadvantage compared to European companies. North American companies will be forced 

to construct and maintain their own costly test facilities or test in Europe, which is problematic due to 

concerns about intellectual property (IP), scheduling, shipping, and cost. 

This disadvantage could potentially result in a missed opportunity for North American companies to 

participate in a rapidly growing business. The Global Wind Energy Council estimates that the annual 

global market for wind turbines could reach $80 billion by 2020.4

 In addition, the lack of facilities 

jeopardizes the success of programs such as the DOE Low Wind Speed Technology (LWST) and offshore 

programs to reduce the cost of energy of land-based and offshore machines to levels competitive with 

fossil fuels. 

2.2.1 NWTC Blade Test Facility Limitations 

The NWTC is limited to testing blades less than 50 m in length (3 MW) and is small compared to the 

existing European facilities (Figure 3). 

0

20

40

60

80

100

120

Vestas NWTC RISØ

Spaerker

WMC NaREC CENER LMGlasfiberBLAEST

Max. Blade Length (m)

Figure 3: Maximum blade length capacities for blade test facilities worldwide 

 

4

 Wind Force 12 http://www.ewea.org/fileadmin/ewea_documents/documents/publications/reports/wf12-2005.pdf 
Wind turbines have grown rapidly in size since testing began at the NWTC in 1990. The Industrial User 

Facility was commissioned in 1997 to test blades up to 34 m. In 2005, a test stand was constructed outside 

of the facility to allow static and fatigue testing of blades up to 50 m to bridge the gap to the development 

of a larger facility. Static testing is conducted outdoors on the inclined face because there is insufficient 

clearance inside the building. Modal and fatigue testing are conducted indoors using the adjacent, vertical 

face that allows the blades to extend into the building through a large door (Figure 4). 

Figure 4: 50-m blade test stand outside of the NWTC blade test facility 

In 2001, the Wind Program began plans to construct an 8-MW dynamometer and 70-m blade test facilities 

at the NWTC to support the growing turbine platforms developed in the LWST Program. The combined 

cost of the facilities was anticipated to be approximately $24 million. According to the DOE Order 413.3, 

Program and Project Management for the Acquisition of Capital Assets, DOE projects costing more than 

$5 million require four critical decisions before a project proceeds. The first decision, Mission Critical 

Need Statement (CD-0), was approved in June 2004, but progress stopped before a Conceptual Design 

Report could be completed because the facility was not included in the DOE Office of Energy Efficiency 

and Renewable Energy's FY06 Budget Request to Congress. At the time of this writing, there are no plans 

to pursue test facilities that are fully funded by DOE. 

Two additional limitations of the facility are the lack of a blade preparation area and the absence of an 

additional large test stand. These two limitations dramatically reduce testing throughput and often result 

in testing backlogs. The lack of a sheltered blade preparation area extends the overall test time by 

requiring that the blades be installed in the test area for approximately 1 month while strain gauges and 

other instrumentation are applied. Long lead times, manufacturing complexities, and unexpected delays in 

manufacturing and testing blades make accommodating the varying schedules of many blade 

manufacturers difficult with only one test stand and can result in delayed development schedules or 

insufficient testing. 

6

Other limitations are related to blade movement and positioning. The blade test facility bridge crane can 

not reach the new 50-m stand. Until this modification is made, relatively expensive mobile cranes must be 

hired to position the blades on the stand. The NWTC also lacks blade-moving and blade-positioning 

equipment for blades longer than 34 m. In addition, the NWTC roadways are not sized for movement of 

blades longer than 34 m. 
7

 

2.2.2 Barriers to Construction of New Test Facilities in North America without Government 

Assistance 

A common perception exists: The North American wind industry is of sufficient size to provide its own 

blade testing or attract private testing companies to conduct testing. However, there are several barriers to 

wind industry members or a private testing company constructing private blade test facilities independent 

of government assistance. These barriers are summarized here. 

Large capital investment —Construction of a blade test facility capable of fatigue testing 70-m blades 

requires a large initial capital investment of at least $5 million to $11 million. One primary reason 

industry has not constructed a large blade test facility is the large capital and operating costs. Some 

manufacturers can perform static proof load testing on their blades, but fatigue testing is significantly 

more difficult and expensive. Fatigue testing facilities require a large investment in hydraulic systems and 

loading devices. The hydraulics, load devices, and instrumentation required for fatigue testing account for 

roughly 25% of the cost for a blade test facility and dramatically increase the building size requirements. 

Dedicated technical staff required —Fatigue testing requires a dedicated staff of at least four technical 

experts. In addition to requiring more equipment, fatigue testing is significantly more complex than static 

testing, and therefore, requires a technical staff dedicated to blade testing. The complexity is inherent in 

the long test durations, monitoring requirements, and inevitable unexpected events involved with fatigue 

testing. In addition, fatigue testing technology is still a research area in many respects. New fatigue test 

methods, loading techniques, data acquisition, and failure theories are being developed. For example, the 

test engineers and technicians at the NWTC blade test center each have dedicated more than a decade to 

developing their blade testing skills and knowledge. 

Unattractive ROI —The costs to construct and operate a large blade test facility make the return on 

investment unattractive for private testing companies. Blade preparation, modal, fatigue, and static blade 

testing require roughly 3 to 4 months of facility time under normal conditions. Most North American 

blade or turbine manufacturers do not have sufficient revenue or testing demand to justify constructing 

and staffing a facility capable of fatigue testing large blades. For example, the Danish company LMGlasfiber is one of only a few blade manufacturers in the world that also performs fatigue testing. As a 

global supplier of blades to many companies, LM is very large relative to U.S. blade companies, with 

more than $350 million in revenue in 2004 and 2,430 employees5

. In contrast, the largest U.S. blade 

manufacturer, TPI Composites, reports 300+ employees—many of whom work in the transportation or 

military divisions 6

. 

Unstable U.S. market—The inconsistency of the production tax credit (PTC) has resulted in an uncertain 

U.S. market for wind turbines that has discouraged long-term investments in the infrastructure. As such, 

investment in a large blade test facility is considered risky by private companies as the market conditions 

may change before it could be utilized. 

Insufficient testing demand—Most North American blade and turbine manufacturers have insufficient 

testing demand to fully occupy their own, company-specific, large blade test facility. 

2.2.3 Barriers to Using European Blade Test Facilities 

A number of European large blade test facilities have been constructed in the past 5 years. 

Figure 5 displays the locations and capacities of these facilities. An overview of these facilities is 

provided in Appendix 1: Overview of European Blade Test Facilities. 

5

 LM Glasfiber Holding A/S Financial Highlights: First Half of 2005; http://212.97.129.207/upload/lm_fin_2005_q2_uk.pdf 6

 TPI Composites Home Page: About TPI; http://www.tpicomposites.com/index.php?id=1067 
Risoe Sparkær

50m

LM Glasfiber

42m, 62m, & 80m

WMC Group 

60m

New and Renewable 

Energy Center (NaREC)

70m

CENER 70m (2006)

Spain

France

Germany

Den.

United 

Kingdom Neth.

Ireland

Risoe/Force/DNV 

Risoe Sparkær 100m

50m

LM Glasfiber

42m, 62m, & 80m

WMC Group 

60m

New and Renewable 

Energy Center (NaREC)

70m

CENER 70m (2006)

Spain

France

Germany

Den.

United 

Kingdom Neth.

Ireland

Risoe/Force/DNV 

100m

Figure 5: European blade test facility locations and capacities 

Although it may be possible for North American companies to use European blade test facilities, concerns 

about IP, scheduling, and cost make the North American industry’s dependence on these facilities 

problematic. 

With the exception of LM Glasfiber, all blade test facilities in Europe are known to have received partial 

funding by their governments. In general, government-funded European test facilities were built to 

support the industry of the respective country. Conflicts of interest may arise when scheduling blade tests 

for North American companies that are potential competitors. In addition, European institutions may be 

much less flexible in accommodating relatively common requests by companies in North America for 

special tests or requests to accommodate delays in providing blades for testing. 

The cost and delay of shipping blades overseas for testing would be problematic for U.S. companies. The 

preferred solution, especially for longer blades, is to build the blades in the country in which they will be 

installed to reduce shipping costs and risk of damage. Although large companies are positioned to 

compete for access to blade test facilities in Europe, smaller manufacturers may be disadvantaged. In 

addition, these manufacturers would be forced to send staff on costly and time-consuming foreign travel 

to supervise testing. 

Recent growth of wind turbine manufacturers and increases in financial investments have led to more 

emphasis on safeguarding intellectual property and protecting company information on development 

schedules and plans. Innovations in blade construction and airfoil design and protected information about 

blade failures and product lines are more difficult for North American companies to protect at European 

institutions than at U.S. facilities; NREL has demonstrated the ability to safeguard protected company 

information for U.S. companies through nearly two decades of testing experience. 

8
3 Requirements and Costs of a Large Blade Test Facility 

Due to the considerable size and forces associated with large blade testing, a blade test facility has a 

number of unique requirements. These requirements are identified here to facilitate the development of 

cost estimates and strategies for pursuing a blade test facility. Table 1 and Table 2 summarize the key 

requirements and costs for a large blade test facility for land-based and offshore turbines. More detailed 

requirements and cost information are provided in Appendices 2 and 3. 

The requirements and costs are rough approximations based on previous experience and vendor quotes. 

The building costs were obtained using 2005 RSMeans Facilities Construction Data for office and factory 

floor space. The approximations are site-dependent and are sensitive to factors such as the price of steel 

and concrete. For this reason, the costs and requirements are intended only to help in strategy formulation. 

The costs and requirements will continue to be refined as the collaboration and facility plans evolve. 

Table 1: Key Facility Requirements for a Large Blade Test Facility 

Feature

Single Test 

Stand (Basic 

Testing)

Multiple Test 

Stands 

(Sustainable 

Financial 

Operation)

Additional 

Capability for 

100-m 

Capacity

Testing capabilities

Total number of test stands 1 2 to 3

Blade length capacity 70m (7MW) 70m (7MW)

100m 

(10+ MW)

Static load capacity 50 M ft-lb 50 M ft-lb 150 M ft-lb

Accredited testing laboratory x x

Flap twist off-axis static testing x

Resonant fatigue flapwise testing x x

Resonant edgewise fatigue testing x x

Force-displacement fatigue testing (using 

bell crank) x

Simultaneous two-axis fatigue testing 

(resonant flap testing and forcedisplacement edgewise testing) x

Staffing 4 4

Location

Port access x x

Outdoor storage for blades x x

Building

Indoor blade prep area x x

Total floor space for blade prep and testing 

100' wide 

300' long 

40' tall

150' to 200' 

wide 

300' long 

50' tall

+75' wide 

+100' long 

+25' tall

9
Table 2: Summary of Cost Estimates for a Large Blade Test Facility ($ in Thousands)

 Basic Testing 

 One 70-m test stand 

+ prep area 

Two 70-m test stands 

+ prep area 

 Three 70-m test stands 

+ prep area 

 Additional cost to 

upgrade one stand to 

100-m capacity 

New Building 2,100 4,422 4,422 + 630

Specialized Building Modifications (test 

stand, load attachment points, etc....) 1,350 1,875 2,400 + 1,250

Blade Movement & Positioning 

Equipment 410 785 1,270 + 710

Test Hardware 440 760 880 + 230

Hydraulics 445 730 1,065 -

Instrumentation 160 272 384 -

Total 4,905 8,844 10,421 + 2,820

 Sustainable Financial Operation 

3.1 Testing Capabilities 

The cost and size of a blade test facility depend primarily on the number of test stands and the blade 

length capacity. The requirements and costs have been developed for three scenarios (Basic Testing, 

Multiple Test Stands, and a 100-m Test Facility) to help bracket the number and capacity of the test 

stands. The scenarios were chosen to span the likely range of facility sizes and are not intended to 

constrain the development of a business plan. 

3.1.1 Basic Testing 

The Basic Testing scenario represents the minimum facility requirements to ensure adequate blade 

integrity and meet certification requirements. This scenario represents a low-cost facility, and as such, has 

several limitations. For example, the facility would not be able to provide a full range of tests, such as 

force-displacement fatigue testing, two-axis fatigue testing, or off-axis static testing of flap-twist blades. 

In addition, the facility throughput would be slow, and the facility may not be able to provide enough 

revenue to cover the operational expenses. 

A basic facility would have a single test stand with a blade length capacity of 70 m and an enclosed blade 

preparation area. The test stand shall have an overturning moment capacity of 50 million ft-lbs and can 

accept deflections to failure for both flap and edge loading. This blade length corresponds roughly to a 7-

MW machine and will enable testing of all wind turbines in production today. (The largest machine in 

production is currently the German REpower Systems 5-MW machine, which uses 61.5-m blades7

.) 

NWTC experience has shown that the long lead times, manufacturing complexities, and unexpected 

delays in manufacturing and testing blades make test scheduling challenging with a single test bay and 

can result in delayed development schedules or insufficient testing. Preparing the measurement 

instrumentation for each blade test is a time-consuming process requiring a blade preparation area. The 

facility shall also be located in proximity to a port where transport of long blades can be accommodated. 

 

10

7

 REpower 5M Brochure; www.repower.de/fileadmin/download/produkte/RE_PP_5M_uk.pdf 
3.1.2 Multiple Test Stands 

The multiple test stand scenario represents a larger facility that more effectively accommodates industry 

members’ schedules, generates more income to recover the facility operating and maintenance costs, and 

reduces risk by increasing the statistical significance with multiple tests and by providing a full range of 

testing. A financially sustainable facility with fewer scheduling conflicts would require two or three 70-m 

test stands. In addition, the facility should be capable of simultaneous two-axis (edge-wise and flapwise) 

fatigue tests, which are more accurate than separate tests8 and will increase facility throughput. Present 

blade testing methods require a $200,000 bell crank system (Figure 6) to achieve two-axis testing on a 70-

m test stand. 

Figure 6: Bell crank system (painted yellow) used in the 34-m NWTC Blade Test Facility for 

edgewise fatigue testing 

The cost of a multiple-test-stand facility is nearly double (roughly $9M) the cost of a basic test facility. 

From experience, it would be prudent to include expansion capacity into any new test facility to allow for 

1) additional test stands to be added, 2) longer blades to be tested, and 3) additional test buildings. 

Another option would be to construct a building large enough for multiple stands but add equipment as 

funding allows. 

The costs for adding an additional building and test equipment at a later time depend on the building and 

equipment purchased for the original facility. A rough estimate of these costs is included in Appendix 3. 

These expansion costs have not been thoroughly explored, but it may be possible to defer roughly $3 

million in costs for items such as the building, moment foundation, test hardware, hydraulics, and 

instrumentation. However, expanding the facility at a later date will ultimately result in higher capital 

costs and some disruption to facility operations. 

3.1.3 100-m Blade Test Facility 

Historically, predictions about wind turbine size increases have underestimated the growth in turbine size. 

Offshore wind energy is an emerging technology that has tremendous potential in the mid- to long term. 

Offshore turbine technology could result in a dramatic increase in the size of future wind turbines. 

Although no wind turbines larger than 6 MW are currently known to be under design, it is possible that 

facilities larger than 70 m will be needed in the next 5 years. For these reasons, the 100-m blade test 

facility scenario explores the cost to construct a test facility with a 100-m capacity. This scenario is only 

intended to define the upper limit of feasible possibilities. Construction of expandable facilities and 

construction of facilities between 70 m to 100 m should be further explored. 

11

 

8

 More accurate testing reduces blade uncertainty and cost and may be required by certification agents and investors. 
The additional requirements and costs of a replacing a 70-m test stand with a 100-m test stand are listed in 

the appendix. It is important to note that the foundation strength and blade loads required to test longer 

blades increase much more quickly than the blade length (Figure 7). Accordingly, a relatively small 

increase in blade length test capacity translates into a relatively large increase in test facility cost. 

-

10,000,000

20,000,000

30,000,000

40,000,000

50,000,000

60,000,000

70,000,000

0 20 40 60 80 100 1

Blade length (m)

Ultimate Strength of the Blade Root (ft-lb)

NWTC 50-m test stand

20

Figure 7: Ultimate strength of the blade root relative to the blade length9

3.2 Building Requirements 

Construction of a new building represents roughly half the cost of a blade test facility. To reduce cost, it 

may be possible to find an existing building large enough to accommodate a blade test facility. Roughly 

30,000 to 60,000 ft2

 of unobstructed floor space and at least 40 ft of vertical clearance are required for 

blade test and blade preparation area (see Table 1 for the building dimensions). If a suitable building is 

located, it is expected that the floor in the interior of the building will be removed and replaced with a slab 

to accommodate the test stand and load attachment points. 

Office space must also be available in the building or nearby. Several site-dependent improvements (such 

as road and building access, electrical improvements, etc.) may be required if an existing building is 

found or if a new building is constructed. The costs for these items included in this report assume a new 

building is constructed and do not account for any road improvements that may be necessary. 

A primary requirement for a large blade test facility is that it has seaport access to accommodate 

transportation of the large blades. It is anticipated that future offshore blades will be manufactured near 

ports to overcome land-based length and height transportation restrictions. The location must also provide 

sufficient outdoor storage area (at least 3 acres) for temporarily storing blades and equipment before and 

 

12

9

 Preliminary Draft of the Final Report for the Large Blade Test Facility Scaling Study; Darris White and Walt Musial, August 

9, 2004 
13

after testing and for maneuvering heavy equipment. Some possible locations include North American 

ship-building facilities and ports that need economic revitalization, closed Federal naval bases, and other 

facilities with coastal access. An in-depth survey of potential sites should be performed. 

3.3 Revenue Model 

A business model demonstrating sufficient revenue to recover operating expenses after the initial capital 

investment is desirable to reduce partner commitments and ensure the long-term survival of the test 

facility. To obtain self-sufficiency, the facility must provide enough revenue to operate and maintain the 

facility and equipment, compensate staff, and make repairs as needed. A crude revenue model has been 

created as an example and is shown in Table 3. The revenue model assumes that NREL operates the blade 

test facility. Thus, the overhead and labor-loading rates are consistent with NREL practices. As a 

government-owned laboratory, there is no insurance cost as the government is self-insured. In addition, 

the revenue model assumes that the building was purchased and that there is no lease or mortgage. 

The revenue of a blade test facility depends on the number and length of blades tested. The revenue 

generated by a blade test facility can be obtained from compensation for time and materials. Based on 

NWTC experience and conversations with European blade testing facilities, a full suite of testing on a 1.5-

MW (34-m) blade requires 3 to 4 months and costs roughly $300,000. As a first estimate, the cost of 

testing longer blades can be assumed to increase linearly with the length of a blade and require an 

additional month for fatigue testing. Thus, a 70-m blade will generate roughly $600,000 in revenue. Based 

on these assumptions, testing 70-m blades can theoretically result in more annual revenue than 34-m 

blades. 

The number of blades tested in a given year is variable due to factors such as premature failures, 

manufacturing delays, and demand for new land-based and offshore wind turbine designs. The demand 

for new designs depends largely on the success of wind turbine markets that are difficult to predict 

because they are largely dependent on policy factors and fossil energy prices. 

Some qualitative comments can be made about the demand to test blades at the new blade test facility. It 

is not unreasonable to expect that the demand will be about twice the demand experienced by the NWTC 

blade test facility. The rational for this expectation is based on the idea that, although more land-based 

turbines are being deployed, the number of new land-based turbine models developed by North American 

manufacturers will continue at the pace observed over the past 2 years. Additionally, a similar amount of 

test demand could be created by the involvement of North American manufacturers in the offshore market. 

Several scenarios of varying facility throughput were considered for blade test facilities of various sizes. 

However, because of the difficulty of quantitatively forecasting the demand for the blade test facility, 

Table 3 presents the results of simplified calculations that assume only 70-m blades are tested and the 

maximum facility throughput. The supporting calculations are listed in Appendix 4. 
Table 3: Approximate Maximum Annual Net Revenue from a Blade Test Facility 

One Test Stand Two Test Stands Three Test Stands

Number of 70m tests per year 3 6 9

Annual Revenue $ 1,800,000 $ 3,600,000 $ 5,400,000

Expendable Materials $ (244,398) $ (488,796) $ (733,194)

Facilities Fixed Expenses $ (1,403,714) $ (1,466,072) $ (1,528,430)

Net Revenue $ 151,888 $ 1,645,132 $ 3,138,376

The expendable materials category listed in Table 3 includes electricity for the hydraulic systems, strain 

gauge materials, and materials for constructing the saddles used to transfer loads to the blade. The fixed 

expenses category includes items such as staff compensation, facility utilities and maintenance, and 

capital equipment maintenance and replacement. The largest component of the fixed expenses is the staff 

salaries (roughly $750,000 per year). 

Based on the assumptions above, the maximum net revenue from a multiple-test-stand facility is 

dramatically higher than a single-test-stand facility. The low net revenue from a single-test-stand facility 

is an indication of the difficulty of creating a sustainable enterprise with only one test stand even when 

assuming maximum facility throughput. In fact, if the single-blade-test facility tests only two rather than 

three 70-m blades in a given year, the annual revenue loss is roughly $900,000. 

14
15

4 Collaboration Structure 

This section describes some of the potential partners, contributions, ownership options, and operational 

structures for a North American blade test facility collaboration. The collaboration could take many forms 

with a variety of partners. This section presents general ideas that would be refined once interested parties 

are identified. 

The scope of this paper is limited to a blade test facility; however, a blade test facility may be part of a 

larger facility that supports testing of offshore wind turbines, wave energy, and tidal energy technologies. 

In addition to a blade test facility, the services offered by such a center could include certification and 

permitting assistance, a drivetrain test facility, land-based and offshore wind turbine testing, wave testing, 

marine current testing, environmental testing, and acoustic testing. 

4.1 Collaboration Partners 

A number of international, federal, academic, state, municipal, and private entities could be interested in 

the development of a blade test facility collaboration in North America. Federal agencies, state entities, 

and municipalities may be interested in fostering renewable energies, stimulating local economic growth, 

or revitalizing an industrial area. Wind turbine and component manufacturers may be motivated to 

advance the collaboration in order to test their products and designs. Academic institutions and research 

laboratories may be motivated by the potential to become involved in research activities and to facilitate 

professional development of their faculty and staff. The collaboration is also in line with the mission of 

research laboratories such as NREL. For example, NREL’s mission is to develop renewable energy and 

energy efficiency technologies and practices, advance related science and engineering, and transfer 

knowledge and innovations to address the nation's energy and environmental goals. 

4.2 Partner Contributions 

The requirements for a blade test facility can be summarized into six key components. Table 4 lists the 

collaboration members who might be able to contribute these components. 
16

Table 4: Key Requirements for a Blade Test Facility and Possible Contributions of Collaboration 

Members 

Federal DOE NREL State 

Entity 

Municipal 

Entity 

Academic 

Institute or 

Laboratory 

Industry 

Partners 

Land 

(near port 

facilities) 

x x x x 

Building x x x x x x 

Test Stand x x x x x x 

Test 

Equipment 

x x x x x x x 

Facility Staff x x x x x x x 

Staff Training x 

Commitments 

to Testing 

x x 

 

4.2.1NREL Contributions 

NREL’s NWTC has the only blade test facility in the United States capable of performing full-scale 

testing of megawatt-size wind turbine blades. Since 1989, NREL has tested more than 140 blades under 

fatigue and static loading. This experience will be crucial to establishing new blade test facilities in the 

United States. NREL could transfer this technology through professional advice, training, or even staff to 

help operate the facility. 

In addition to technical expertise, NREL’s NWTC is accredited through the American Association for 

Laboratory Accreditation (A2LA). A2LA is a signatory to several bilateral and multilateral recognition 

agreements. These agreements facilitate the acceptance of test and calibration data between A2LAaccredited laboratories and 46 economies around the globe. This accreditation is critical for blade testing 

to conform to requirements of financial and certification institutions such as Germanischer Lloyd. 

Significant effort and documentation are required to maintain laboratory accreditation. NREL’s 

experience in maintaining this accreditation could facilitate the accreditation of the new blade test facility. 

Another important NREL contribution could be the licensing of the NREL blade resonance excitation 

system (B-REX) fatigue testing technology (Figure 8). This technology facilitates less expensive fatigue 

testing that is faster and more accurate. In addition, the technology is being considered for edgewise 

fatigue testing because force displacement loading with a bell crank may be impractical for blades larger 

than 50 m due to the extremely high loads involved. 
Figure 8: Installation of the NWTC B-REX fatigue testing system 

4.2.2DOE Contributions 

DOE could make several contributions to a blade test facility collaboration through leadership, funding, 

and ongoing government support. A crucial DOE contribution could be funding NREL to provide 

technical support or even staff to the facility. A second possible DOE contribution is to provide funds to 

purchase or lease a building, test equipment, or other necessary items. However, all program funds are 

currently committed. In addition, capital projects costing more than $5 million require justification 

through the DOE Critical Decision Process and Congressional approval. 

A third DOE role could be as a user to fund tests at the facility through DOE public/private partnerships 

such as the LWST and Offshore Wind Technology Programs. This commitment, which could take the 

form of a specific number of blade tests per year, would help sustain the operation of the facility. 

4.2.3Federal, State, Municipal, or Academic Contributions 

Federal, state, municipal, or academic entities could contribute land, building, funds, facility staff, or 

other contributions to the project. The costs of the test stand, test hardware, instrumentation, and blade 

movement equipment comprise approximately one-half of the facility’s cost. The building and land 

comprise the other half of the capital investment. In addition to providing capital funds for the 

collaboration, federal, state, municipal, or academic entities may have access to or be willing to purchase 

an existing building or land. Local organizations could provide assistance with zoning and other 

permitting issues while academic institutions may be able to provide staffing or research assistance 

support. Local not-for-profit organizations and academic institutions may also be able to provide business 

oversight, facilities support and receive local development funding. 

4.2.4Industry Contributions 

Industry partners may be able to make similar contributions as federal, state, municipal, or academic 

entities. In addition, a key industry partner contribution could be a commitment to testing blades at the 

facility for a specified number of years. This commitment would reduce the risk of insufficient blade 

testing revenue for sustainable operation of the facility. 

17
18

4.3 Ownership and Operating Models for a Collaborative Facility 

The numerous prospective partners and the nascent status of the collaboration result in many possible 

ownership and operating structures for a collaborative blade test facility. The European test facilities 

provide useful models. 

4.3.1 Ownership of European Test Facilities 

Table 5 summarizes the ownership structures for the blade test facilities in Europe. 

Table 5: European Ownership Models 

RISØ 

(Sparkaer)

BLAEST WMC NaREC CENER LMGlasfiberSiemens Vestas 

Governmentowned facility x x 

Not-for-profit 

enterprise 

x x 

Commercial 

consortium 

x 

Private 

manufacturer 

facility 

x x x 

All of the non-private blade test facilities in Europe received some government funding. The facilities in 

Spain (CENER) and Denmark (Risoe) are government-owned and are operated by a government-funded 

entity. Two European facilities have joint ownership. The WMC in the Netherlands is a foundation 

established by the Energy Research Center of the Netherlands (ECN) and Delft University of Technology. 

The facility was built with government support but relies on commercial work to fund operation. 

The new Danish facility (BLAEST) is a joint venture between a government-funded research institute 

(Risø), a commercial certifying body (Det Norske Veritas or DNV), and an engineering/consulting 

company (Force Technology). BLAEST now also owns Risø’s old test facility in Sparkaer. The shares are 

divided as follows: 40% Risø, 35% Force, and 25% DNV. 

The UK New and Renewable Energy Centre Limited (NaREC) is a self-standing but not-for-profit 

organization. NaREC is a company limited by guarantee—an alternative type of corporation used 

primarily for non-profit organizations that require legal personality. A guarantee company does not have 

share capital, but it has members who are guarantors instead of shareholders. NaREC obtained 

government funding for its operational core costs. Income will be achieved largely through fees for 

services, and after 5 years the company will be financially self-sustaining in terms of its operating costs.10

4.3.2 Ownership and Operation of a Collaborative Facility in North America 

 The ownership models for a collaborative blade test facility can be categorized by the building and land 

owner or lessor. Each of these categories can be subdivided by parties that could operate the facility. 

Table 6 lists four general ownership and operating options for a collaborative blade test facility in North 

America. Each ownership model is described in the following sections. 

 

10 Renewable Energy for Europe http://europa.eu.int/comm/energy/en/renewable/idae_site/deploy/prj094/prj094_5.html 
Table 6: Summary of North American Blade Test Facility Collaboration Ownership Models 

Building/Land 

Owner or Lessor 

Facility 

Operation 

Comments 

DOE 

(NREL Extension) 

MRI-Battelle DOE acceptance of donated property is difficult 

Donation of DOE property is restricted to non-profit entities 

Research overhead and labor rates are high 

Not-for-profit 

enterprise 

(state, municipal, or 

academic) 

Academic 

MRI-Battelle 

Other organization 

Commercial enterprise 

(UL) 

Commercial entity 

MRI-Battelle 

Potential problems with the return on capital investment being 

sufficient to attract investor interest 

Wind industry 

manufacturer (Clipper, 

TPI, GE, NPS ....) 

Manufacturer 

MRI-Battelle 

Potential problems with IP protection and schedule conflicts 

4.3.2.1 Facility Owned and Operated by DOE 

NREL and the NWTC are owned by DOE and operated by Midwest Research Institute (MRI) and Battelle. 

A similar ownership and operating arrangement could be used for the 70-m blade test facility at a location 

near a seaport. Although current federal budget constraints make full federal funding of the facility 

unlikely, contributions from collaboration partners could make an extension of the NREL facility feasible 

at a different location. For example, if collaboration partners could provide a building and funding to 

construct the test stand, DOE may be able to fund the remaining facility components. 

The primary advantage of a facility owned and operated by DOE is that the operation, management, and 

accreditation procedures for the laboratory could be extended to the new facility. In addition, DOE is an 

objective owner, and MRI-Battelle have demonstrated outstanding proficiency in operating the NWTC 

blade test facility. 

One potential problem with this arrangement is the difficulty of DOE to assume ownership of donated 

property or co-own property with another party. The assumption of donated property by DOE is 

uncommon due in part to the potential liability associated with property acquisitions. 

DOE is subject to political decisions. An independent enterprise may be desirable to ensure the survival of 

the blade test facility. A potential disadvantage of a DOE-owned facility is the restrictions in converting a 

DOE-owned facility into an independent enterprise. DOE property can be relatively easily transferred to 

another party if the party is non-profit and is performing research in the interest of DOE. 

A disadvantage of an NREL extension is the high labor and overhead rates associated with research 

institutes such as NREL. Alternatives to the typical laboratory overhead and labor structures should be 

sought if these rates prohibit sustainable financial operation of the facility. 

4.3.2.2 Facility Owned by a Not-for-Profit Entity 

This ownership model is similar to the above approach but differs in that a not-for-profit entity (such as a 

university, state, or municipal organization) would own or lease the building and land. Operation of the 

facility could be performed by an organization such as a university or by MRI-Battelle as a subcontract or 

as part of a cooperative research and development agreement (CRADA). 
20

 

A CRADA could also be a convenient vehicle for DOE to contribute test equipment, operate the facility, 

or contract tests with industry through Work for Others agreements.11 Alternatively, it may be possible to 

donate test equipment to the not-for-profit organization. 

There are advantages to this approach. It is commonly used in other research settings and follows 

demonstrated models used to operate European blade test facilities. In addition, the facility is amenable to 

the formation of a non-profit or commercial enterprise as the limited involvement of DOE lessens some of 

the property ownership restrictions. 

4.3.2.3 Facility Owned by One or More Commercial Entities 

This ownership model is similar to the new Danish joint venture (BLAEST) among a government-funded 

research institute (Risø), a commercial certifying body (DNV), and an engineering/consulting company 

(Force Technology). Ownership and operation of the facility in this scenario would be by one or more 

commercial entities. It could also be possible for MRI-Battelle to operate the facility. The objective would 

be to form a commercial enterprise for profit. One challenge of a facility owned by a commercial entity is 

establishing a return on investment sufficient to maintain investor interest. 

4.3.2.4 Facility Owned by a Wind Industry Manufacturer 

A facility operating in this structure would be primarily owned by an industry partner such as a turbine or 

blade manufacturer. DOE financial or technical support may be possible if the partner allowed tests from 

other industry members to be performed at the facility. The motivation for DOE’s involvement would be 

to obtain a testing facility that could be made available to the interested industry member and other 

industry partners. The facility could be operated by the industry member or a third party such as NREL. 

The advantage of this approach is that a few private companies currently have the facilities and equipment 

to move and manipulate large blades. On-site expertise is already available to handle most of the testing 

and preparatory processes. Existing private companies also have staffing, insurance, and other business 

processes in place to easily facilitate operation of a new test facility. A cost estimate for such a 

collaboration is included in Appendix 3. This scenario saves approximately $600K in equipment and 

nearly $2 million in building costs from the Basic Testing Scenario. 

There are several fundamental challenges to this collaboration structure. Federal assistance will require 

the facility to also be available to other industry members. Other industry partners will likely require 1) 

assurance of IP protection, 2) a facility managed and run by an objective third party such as NREL, and 3) 

accreditation to be accepted by certification agents and the financial community. These requirements may 

be difficult to meet if the facility is owned by a single private party. 

It may be possible for industry members to collaborate. For example, a blade manufacturer and turbine 

manufacturer could collaborate in constructing test facilities. If the arrangement were to benefit several 

industry partners, it may also be possible for DOE and NREL to provide technical support, staffing, or a 

commitment to testing. However, conflicts of interest among industry partners and proprietary 

information will create challenges to this arrangement. This paper does not explore options directly 

between industry partners as they are best qualified to explore these options. 

11 NREL Transferring Technologies www.nrel.gov/technologytransfer/partnering.html#crada 
21

 

5 Summary 

The wind power industry in North America has an immediate need for larger blade test facilities to ensure 

the survival of the industry. Blade testing is necessary to meet certification and investor requirements and 

is critical to the success of the wind turbine industry. DOE’s Wind Program is exploring options for 

collaborating with government, private, or academic entities in a public/private partnership to build larger 

blade test facilities in North America capable of testing blades up to at least 70 m in length. Current 

Program funding levels and the impact of congressionally directed activities at this time require that any 

further development of a facility be conducted with significant industry participation and cost share. 

Necessity for a Large Blade Test Facility 

• Rapid growth in wind turbine size over the past two decades has outstripped the capacity of blade 

test facilities in North America, hindering the North American wind turbine and component 

manufacturers’ opportunities to participate in what the Global Wind Energy Council estimates 

could become an annual global market of $80 billion by 2020.12

• The North American wind industry has no practical options for testing blades greater than 50 m in 

length. The NWTC blade test facility can presently only perform limited testing on blades up to 

50 m. 

• The use of European large blade test facilities by North American manufacturers is problematic 

due to concerns about intellectual property, scheduling, and cost. 

Primary Benefits of Facility Construction 

• Directly supports the President’s Advanced Energy Initiative goal and Departmental priorities of 

expanding access to wind energy through technology

• Allows wind turbine manufactures to meet certification and investor requirements for wind turbine 

blades

• Provides a development path for new products and technologies used in large land-based and 

offshore wind turbines

• Helps understand the failure mechanisms for technologies used to manufacture very large wind 

turbine blades thereby reducing the risk and cost of manufacturing, servicing, and warranting large 

turbines thereby reducing the cost of electricity from wind turbines

• Maintains the competitiveness of U.S. wind turbine manufacturers with European companies and 

helps ensure U.S. participation in what is predicted to be more than $80 billion of annual global 

business by 2020. 

• Provides an economic magnet for similar businesses to relocate to a particular region. 

Facility Requirements 

• A primary requirement for a large blade test facility is port access to accommodate transportation 

of the large dimensions of offshore designs. 

• Preliminary cost estimates for a blade test facility (assuming a new building is constructed) are 

roughly: 

o $5 million for a basic 70-m single-test-stand test facility without office space or the ability 

to do a full suite of testing 

o $9 million for a two-test-stand facility with office space and full testing capability 

(potentially up to $3 million of this initial investment could be deferred) 

o $11 million for a three-test-stand facility 

o An additional $3 million to upgrade a 70-m test stand to a 100-m test stand. 

12 Wind Force 12 www.ewea.org/fileadmin/ewea_documents/documents/publications/reports/wf12-2005.pdf 
22

• Construction of a new building represents roughly half of the cost of a blade test facility. To 

reduce cost, it may be possible to find an existing building large enough to accommodate a blade 

test facility. 

• A self-sustaining business model is desirable to reduce partner commitments and help ensure the 

long-term survival of the test facility. To obtain self-sufficiency, the facility should provide 

enough revenue through service fees to operate and maintain the facility. 

• A full-service, multiple-test-stand facility will more effectively accommodate industry members’ 

schedules, generate more income to recover the facility operating and maintenance costs, and 

reduce risk by increasing the statistical significance with multiple tests and by providing a full 

range of testing. 

Collaboration Structure 

• The numerous prospective partners and the nascent status of a North American collaboration result 

in many possible ownership and operating structures for a collaborative blade test facility. This 

report categorizes the ownership models into four general options according to the land/building 

owners or lessors: ownership by 1) DOE, 2) non-profit entities, 3) commercial entities, and 4) 

wind industry manufacturers. 

• Options for operation of the facility include operation by an academic institution, MRI-Battelle, a 

commercial entity, a manufacturer, or formation of a new entity. 

• NREL is well suited to provide technical advice and training, licensing of the B-REX technology, 

and operation of the facility. Limited DOE funds for construction or equipment and commitments 

to testing may be possible depending on future budgets. 
Appendix 1: Overview of European Blade Test Facilities 

There are five non-private blade test facilities in Europe (Figure 9 and Table 7), and several 

manufacturers such as Enercon and LM Glasfiber own private facilities with limited in-house test 

capabilities. The newer facilities such as BLAEST, WMC (Figure 11), and NaREC (Figure 13) are near 

ports. Figure 10 provides an overview of the maximum blade length for each facility. 

Risoe Sparkær

50m

LM Glasfiber

42m, 62m, & 80m

WMC Group 

60m

New and Renewable 

Energy Center (NaREC)

70m

CENER 70m (2006)

Spain

France

Germany

Den.

United 

Kingdom Neth.

Ireland

Risoe/Force/DNV 

Risoe Sparkær 100m

50m

LM Glasfiber

42m, 62m, & 80m

WMC Group 

60m

New and Renewable 

Energy Center (NaREC)

70m

CENER 70m (2006)

Spain

France

Germany

Den.

United 

Kingdom Neth.

Ireland

Risoe/Force/DNV 

100m

Figure 9: European blade test facility locations and capacities 

23
0

20

40

Vestas NWTC RISØ

Spaerker

WMC NaREC CENER 

Max. Bla

60

80

100

120

LMGlasfiberBLAEST

de Length (m)

Figure 10: Maximum blade length capacities for blade test facilities worldwide

24
25

Table 7: Overview of European Blade Test Facilities 

Test 

Facility Location

Year 

of

Start 

Max 

Blade 

Length 

(m) 

No. of 

Test 

Stands

Approx 

Test 

Bay 

Area 

(m2) 

Approx 

Cost 

Approx 

Staff Comment

RISØ 

Sparkaer Denmark 1995 50 5 1000

Not 

Avail. 10

Government funded; RISØ operated; Dan

www.risoe.dk/rispubl/VEA/sparkae

Blade Test Center A/S (BLAEST) 

Viborg Denmark 2005 100

Not 

Avail. 

Not 

Avail. 

Not 

Avail. 

Not 

Avail. 

Industry consortium: RISO/Force/DNV 

www.blaest.com/

WMC 

Wieringermeer Netherlands 2002 60 2 2000

Not 

Avail. 15 

TU Delft/ECN enterprise; self-sustaining 

www.wmc.tudelft.nl/index.html

New and Renewable Energy Center (NaREC) 

Blythe UK 2005 70 2 1750 $5M 6

UK enterprise; government funded 

www.narec.co.uk/facilities-blade-te

CENER 

Pamplona Spain 2006 75 2 2000

Not 

Avail. 

Not Avail. 

New government facility 

www.cener.com/cener/?scc=57

LMGlasfiber Denmark 2005 80 6 1200 Not Avail. 9 Private; LM blades only www.lmglasfiber.com/TechnologyVestas Blades UK 

Not 

Avail. 40

Not 

Avail. 

Not 

Avail. 

Not 

Avail. 

Not 

Avail. Private test facility; formerly NEG Micon
Figure 11: The WMC blade test facility 

Figure 12: LM Glasfiber blade test facility 

26
27

Figure 13: NaREC blade test facility 
Appendix 2: Detailed Requirements for a Large Blade Test Facility 

Table 8: Requirements for a Large Blade Test Facility 

Feature

Single Test Stand 

(Basic Testing)

Multiple Test 

Stands 

(Sustainable 

Financial 

Operation)

Additional 

Capability 

for 100-m 

Capacity Notes

Testing capabilities

Total number of test stands 1 2 to 3

Dramatically increases test throughput and simplifies facility 

scheduling

Blade length capacity 70m (7MW) 70m (7MW)

100m 

(10+ MW)

100m blade testing will ensure testing of very large offshore 

turbines designed to minimize foundation and cabling costs

Accredited testing facility x x

Static load capacity 50 M ft-lb 50 M ft-lb 150 M ft-lb

The bending loads applied to the blade root increase with the cube 

of the blade length!

Flap twist off-axis static testing 1 test at a time Enables testing of next generation blade technology

Resonant fatigue flapwise testing 1 test at a time

2 to 3 tests 

simultaneously

Dramatically increases test throughput and simplifies facility 

scheduling

Resonant edgewise fatigue testing 1 test at a time

Minimum of 2 tests 

simultaneously

Dramatically increases test throughput and simplifies facility 

scheduling

Force-displacement fatigue testing (using bell crank)

Minimum of 2 tests 

simultaneously

Dramatically increases test throughput and simplifies facility 

scheduling

Simultaneous two-axis fatigue testing (resonant flap 

testing and force-displacement edgewise testing)

Minimum of 2 tests 

simultaneously Reduces test time, increases test accuracy

Staffing 4 4

Senior facility engineers 1 1

Test engineers 1 1

Technician / Equipment Operator 1 1

Mechanics / Machinists / Equipment Operator 1 1

Location

Port access x x

Adjacent to marine shipping is mandatory for transportation of 

very large blades

Accessible by trailer tractor or rail x x

Trailer access up to 125 ft is preferred but less important due to 

port access

No overhead road obstructions below 15.8 ft 

(bridges, electric lines, etc....) x x Less important due to port access

Outdoor storage for blades x x 1 acre minimum

Sheltered storage for equipment (actuators, saddles, 

etc...) x x 30 ft x 120ft x 20ft minimum

28
Building

Indoor blade prep area x

Dramatically increases test throughput and scheduling due to 

weather uncertainty

Total floor space for blade prep and testing 

100' wide 300' 

long 40' tall

150' to 200' wide 

300' long 50' 

tall

+75' wide 

+100' long 

+25' tall

Increased width ensures ultimate flap testing capability for the 70m 

stands; increased height enables higher load (quicker) fatigue tests 

for the 70m stand; increased height, width, and length are required 

to accomadate100m blade tests.

Safety equipment and systems (fire, spills, etc....) x x

Control room reinforced for safety x x 20 ft by 30 ft

Electrical Service x x 480, 1000A kW

Meeting / observation Room x Facilitates communication with customers and staff (20 ft by 30 ft)

Office/cubical workspaces x 6 standard office cubes 10ft by 10ft

Machine shop room x x 30 ft by 30 ft

Oil pump room x x 30 ft by 30 ft

Oil cooling pads - outside w/ containment x x 4 pads - 8ft by 8ft each

Test stand foundation 50 M ft-lb 50 M ft-lb 150 M ft-lb

The bending loads applied to the blade root increase with the cube 

of the blade length

Static reaction foundation for side pulls 200,000 lb @20' 200,000 lb @20'

400,000 lb 

@20' Side load increase with the square of the blade length

Miscellaneous building load attachment points x x Required for calibrations, equipments anchoring, etc....

Blade movement & positioning equipment

Overhead gantry cranes Two 35 ton Two 35 ton Two 70 ton Cranes span entire test bay

Jib crane 20 ton 20 ton 40 ton

Marine travel lift 20 ton 40 ton Reduces safety risks and damage to test article

Fork truck 7.5 ton 7.5 ton 7.5 ton

Blade dolly--Custom designed 35 ton 35 ton 70 ton 100m blade is 2.3 times heavier than 70m blade.

Test Hardware

Machine shop equipment and miscellaneous tools x x Lathe, Mill, Saws,....

Static test equipment (4 winches, cables, & 

saddles)

200,000 lb total pull 

capacity

200,000 lb total pull 

capacity

400,000 lb 

total pull 

capacity 4 winches

Flapwise fatigue exciter and saddles

4000 lb oscillating 

mass

4000 lb oscillating 

mass

8000 lb 

oscillating 

mass

Bell crank for edgewise fatigue testing 100,000 lb 

Blades longer than 70m would use untested resonant technology 

for edgewise fatigue

Hydraulics

Controller x x 1 Flex Test II

Pumps 1 @180 GPM 2 to 3 @180 GPM Model 505; Assumes two-axis fatigue testing

3000-psi piping x x

Oil cooling system x x 2 oil-to-air coolers per pump

Instrumentation

Data acquisition x x 64 channels

Video x x 2 cameras w/recorders

NDE Equipment x Blade inspection

PCs 5 6

29
Appendix 3: Approximate Costs for Large Blade Test Facility Options 

Table 9: Approximate Capital Costs for Blade Test Facilities 

Item

 One 70-m test 

stand 

integrated into 

blade manfct 

facility 

 One 70-m 

test stand + 

prep area 

 One 70-m test 

stand + prep 

area with 

option to 

expand to two 

70-m test 

stands 

 Two 70-m test 

stands + prep 

area 

 Three 70-m 

test stands + 

prep area 

 Additional cost 

to upgrade one 

stand to 100-m 

capacity 

New Building 2,100,000 - 2,322,000 4,422,000 4,422,000 630,000

Office Space (2000 sqft) - 222,000 - 222,000 222,000 - 

Construction of New Test facility building 

(25,000; 50,000; or 57,500 sqft) - 2,100,000 2,100,000 4,200,000 4,200,000 + 630,000 

Transportation access improvements Site dependent Site dependent Site dependent Site dependent Site dependent Site dependent

Specialized Building Modifications 1,350,000 1,350,000 1,375,000 1,875,000 2,400,000 + 1,250,000

Control room reinforced for safety 50,000 50,000 50,000 50,000 50,000

Safety equipment and systems 50,000 50,000 50,000 50,000 50,000

Test stand foundation 1,000,000 1,000,000 1,500,000 2,000,000 + 1,000,000

Static reaction foundation for side pulls 200,000 200,000 200,000 200,000 200,000 + 200,000

Load attachment points for misc. vertical loads 50,000 50,000 75,000 75,000 100,000 + 50,000

Blade Movement & Positioning Equipment 225,000 410,000 560,000 785,000 1,270,000 + 710,000

Overhead bridge crane (35 tonn) (2 cranes 

spanning all bays) 225,000 225,000 450,000 900,000 + 450,000

Jib crane - 70,000 70,000 70,000 105,000 70,000 + 

Marine travel lift - - 150,000 150,000 150,000 150,000 + 

Fork truck - 75,000 75,000 75,000 75,000 

Blade dolly (custom design) - 40,000 40,000 40,000 40,000 40,000 + 

Test Hardware 300,000 440,000 640,000 760,000 880,000 + 230,000

Machine shop equipment and miscellaneous tools 30,000 170,000 170,000 170,000 170,000

Static test equipment (4 winches, cables, & saddles) 1 150,000 150,000 150,000 150,000 150,000 + 150,000

Fatigue actuators, exciter, saddles2 120,000 120,000 240,000 360,000 + 80,000

Bell crank (for simultaneous two-axis testing)3 - 200,000 - 200,000 200,000

Hydraulics2 445,000 445,000 445,000 730,000 1,065,000 - 

Controller (1 Station) 150,000 150,000 150,000 150,000 200,000

Pumps (model 505) 150,000 150,000 300,000 450,000

3000-psi piping 70,000 70,000 150,000 230,000

Oil cooling system 35,000 35,000 70,000 105,000

Oil cooling Installation (piping, aux. pump) 40,000 40,000 60,000 80,000

Instrumentation 120,000 160,000 160,000 272,000 384,000

Data acquisition (64 channels) 110,000 110,000 220,000 330,000

Video recording system 10,000 10,000 10,000 10,000 

Non destructive evaluation equipment 30,000 30,000 30,000 30,000 

Personal computers 10,000 10,000 12,000 14,000

Total 2,440,000 4,905,000 8,844,000 10,421,000 + 2,820,000

1

Assumes only one static test can be performed at a time.

2

Assumes single-axis fatigue tests can be performed simultaneously on each stand.

3 Assumes only one bell crank assembly with a 70m blade capacity; longer blades will be tested with dual-axis BREX resonant technology

Basic Testing Sustainable Financial Operation

 1,000,000

 225,000

 120,000

 150,000

 70,000

 35,000

 40,000

 110,000

 10,000

 5,502,000

Red cells indicate items where costs have been deferred

30
Appendix 4: Approximate Net Revenue for a Large Blade Test Facility 

Table 10: Approximate Revenues from Blade Test Facilities 

 Cost Load Factor 

 25,000 sqft, single test stand 

facility + 2000 sqft office space 

 50,000 sqft, two test stand 

facility + 2000 sqft office space 

 75,000 sqft, three test stand 

facility + 2000 sqft office space 

 Approximate yearly cost 

(loaded numbers) 

 Approximate annual cost 

(loaded numbers) 

 Approximate annual cost 

(loaded numbers) 

 4 NREL staff salaries 2.84 $ 846,022 $ 846,022 $ 846,022 

 Capital equipment replacement (for items 

over $50K) 

 1.09 

 $ 24,525 

 $ 32,700 $ 40,875 

 Operating equipment replacement (slings, 

computers, load cells) 

 1.45 

 $ 21,750 

 $ 29,000 $ 36,250 

 Site equipment maintenance (fuel, repairs, 

gov. truck maintenance) 

 1.00 

 $ 10,000 

 $ 10,000 $ 10,000 

 Site management & safety 2.84 

 $ 212,925 

 $ 212,925 $ 212,925 

 Office utilities (less electricity for testing) 1.00 $ 6,000 

 $ 6,000 $ 6,000 

 Office space maintenance 1.00 $ 12,000 $ 12,000 $ 12,000 

 Highbay electricity (less electricity for 

hydraulic pumps) 

 1.00 

 $ 22,500 

 $ 45,000 $ 67,500 

 Highbay heating electricity 1.00 

 $ 14,040 

 $ 28,080 $ 42,120 

 Insurance - - 

 - - 

 Building lease - - - - 

 Subtotal - $ 1,169,762 $ 1,221,727 $ 1,273,692 

 20% Contingency for unanticipated costs - 

 $ 233,952 $ 244,345 $ 254,738 

 Total - $ 1,403,714 $ 1,466,072 $ 1,528,430 

 Two-axis resonant fatigue test, 70-m 

blade, 34 test days 

 Hydraulic unit electricity $ 44,064 540kW, 100% duty cycle 

 Cooling circuit pump electricity $ 2,754 45 kW, 75% duty cycle 

 Air/Oil cooler electricity $ 2,203 36kW, 75% duty cycle 

 Aux electronics electricity $ 245 

 3kW, 100% duty cycle, 

estimate 

 Strain guages $ 7,200 96 gauges @ $75 ea. 

 Adapter plates & fasteners & saddle wood $ 25,000 20K + 2K + 2K respectively 

 Subtotal $ 81,466 

 Two-axis resonant fatigue test, 37-m 

blade, 17 test days 

 Hydraulic unit $ 9,180 225kW, 100% duty cycle 

 Cooling circuit pump $ 704 23 kW, 60% duty cycle 

 Air/Oil cooler $ 1,175 24 kW, 60% duty cycle 

 Aux electronics $ 245 

 3kW, 100% duty cycle, 

estimate 

 Strain guages $ 7,200 96 gauges @ $75 ea. 

 Adapter plates & fasteners & saddle wood $ 25,000 20K + 2K + 2K respectively 

 Subtotal $ 43,504 

 Costs for Expendable Materials for a Full Suite of Tests 

 Fixed Expenses To Operate a Blade Test Facility 

 

31
Annual Net Revenue for a single test stand facility

 Two 34m tests per year Four 34m tests per year One 70m test per year Three 70m tests per year 

 Annual revenue $ 600,000 $ 1,200,000 $ 1,200,000 $ 1,800,000 

 Expendable materials $ (87,007) $ (174,015) $ (81,466) $ (244,398)

 Facilities fixed expenses $ (1,403,714) $ (1,403,714) $ (1,403,714) $ (1,403,714)

 Net Revenue $ (890,722) $ (377,729) $ (285,180) $ 151,888 

Annual Net Revenue for a two test stand facility

 Three 34m tests per year Eight 34m tests per year Two 70m tests per year Six 70m tests per year 

 Annual revenue $ 900,000 $ 2,400,000 $ 1,200,000 $ 3,600,000 

 Expendable materials $ (130,511) $ (348,029) $ (162,932) $ (488,796)

 Facilities fixed expenses $ (1,466,072) $ (1,466,072) $ (1,466,072) $ (1,466,072)

 Net Revenue $ (696,583) $ 585,898 $ (429,004) $ 1,645,132 

Annual Net Revenue for a three test stand facility

 Three 34m tests per year 12 34m tests per year Two 70m tests per year 9 70m tests per year 

 Annual revenue $ 900,000 $ 3,600,000 $ 1,200,000 $ 5,400,000 

 Expendable materials $ (130,511) $ (522,044) $ (162,932) $ (733,194)

 Facilities fixed expenses $ (1,528,430) $ (1,528,430) $ (1,528,430) $ (1,528,430)

 Net Revenue $ (758,941) $ 1,549,526 $ (491,362) $ 3,138,376 

 Maximum Net Revenue 

 One Test Stand Two Test Stands Three Test Stands 

 Number of 70m tests per year 3 6 9 

 Annual revenue $ 1,800,000 $ 3,600,000 $ 5,400,000 

 Expendable materials $ (244,398) $ (488,796) $ (733,194)

 Facilities fixed expenses $ (1,403,714) $ (1,466,072) $ (1,528,430)

 Net Revenue $ 151,888 $ 1,645,132 $ 3,138,376 

32
F1147-E(12/2004) 

REPORT DOCUMENTATION PAGE Form Approved 

OMB No. 0704-0188

The public reporting burden for this collection of information is estimated to average 1 hour per response, including the time for reviewing instructions, searching existing data sources, 

gathering and maintaining the data needed, and completing and reviewing the collection of information. Send comments regarding this burden estimate or any other aspect of this 

collection of information, including suggestions for reducing the burden, to Department of Defense, Executive Services and Communications Directorate (0704-0188). Respondents 

should be aware that notwithstanding any other provision of law, no person shall be subject to any penalty for failing to comply with a collection of information if it does not display a 

currently valid OMB control number. 

PLEASE DO NOT RETURN YOUR FORM TO THE ABOVE ORGANIZATION.

1. REPORT DATE (DD-MM-YYYY)

May 2006 

2. REPORT TYPE

Technical Report 

3. DATES COVERED (From - To)

 

5a. CONTRACT NUMBER

DE-AC36-99-GO10337 

5b. GRANT NUMBER

4. TITLE AND SUBTITLE

Necessity and Requirements of a Collaborative Effort to Develop a 

Large Wind Turbine Blade Test Facility in North America 

5c. PROGRAM ELEMENT NUMBER

5d. PROJECT NUMBER

NREL/TP-500-38044 

5e. TASK NUMBER

WER6 3301 

6. AUTHOR(S)

J. Cotrell, W. Musial, and S. Hughes 

5f. WORK UNIT NUMBER

7. PERFORMING ORGANIZATION NAME(S) AND ADDRESS(ES)

National Renewable Energy Laboratory 

1617 Cole Blvd. 

Golden, CO 80401-3393 

8. PERFORMING ORGANIZATION 

REPORT NUMBER

NREL/TP-500-38044 

10. SPONSOR/MONITOR'S ACRONYM(S)

NREL 

9. SPONSORING/MONITORING AGENCY NAME(S) AND ADDRESS(ES)

11. SPONSORING/MONITORING 

AGENCY REPORT NUMBER

12. DISTRIBUTION AVAILABILITY STATEMENT

National Technical Information Service 

U.S. Department of Commerce 

5285 Port Royal Road 

Springfield, VA 22161 

13. SUPPLEMENTARY NOTES

14. ABSTRACT (Maximum 200 Words)

The wind power industry in North America has an immediate need for larger blade test facilities to ensure the survival 

of the industry. Blade testing is necessary to meet certification and investor requirements and is critical to achieving 

the reliability and blade life needed for the wind turbine industry to succeed. The U.S. Department of Energy’s 

(DOE’s) Wind Program is exploring options for collaborating with government, private, or academic entities in a 

partnership to build larger blade test facilities in North America capable of testing blades up to at least 70 m in length. 

The National Renewable Energy Laboratory (NREL) prepared this report for DOE to describe the immediate need to 

pursue larger blade test facilities in North America, categorize the numerous prospective partners for a North 

American collaboration, and document the requirements for a North American test facility. 

15. SUBJECT TERMS

wind energy; wind turbines; blades; blade test facility; NWTC; CRADA 

16. SECURITY CLASSIFICATION OF: 19a. NAME OF RESPONSIBLE PERSON 

a. REPORT 

Unclassified 

b. ABSTRACT 

Unclassified

c. THIS PAGE 

Unclassified

17. LIMITATION 

OF ABSTRACT

UL 

18. NUMBER 

OF PAGES 

19b. TELEPHONE NUMBER (Include area code)

Standard Form 298 (Rev. 8/98) 

Prescribed by ANSI Std. Z39.18