Attachment A.2
A.2
Investment (Project) Description
A.2.1 Overview
In August 2008, the AEWC Advanced Structures and Composites Center (AEWC), at the
University of Maine (UMaine), was awarded a $4,999,460 grant from the Maine Technology
Asset Fund (MTAF) to begin construction of an Offshore Wind Laboratory. This was followed
by a $12.4 million award from the National Institute of Standards and Technology (NIST) in
January 2010 to complete construction of this facility. When completed in 2011, the Offshore
Wind Laboratory will include a structural test stand and other testing foundations required to
manufacture and test prototype composite components for wind energy applications, including
wind blades, and floating structures up to 70 meters in length for deepwater offshore energy.
Further, the new facility will contain environmental chambers and immersion tanks to perform
durability testing of materials exposed to extreme marine environments.
Figure 1: Offshore Wind Laboratory at the AEWC Advanced Structures and Composites Center.
Brick and mortar costs funded through $5 million MTAF Grant and $12.4 million NIST Grant.
The funding received from MTAF and NIST is restricted to “brick and mortar” construction
costs, with no allowance for testing equipment. Therefore, to outfit the new Offshore Wind
Laboratory, AEWC is seeking $6 million ($3 million EDA grant plus $3 million match from
UMaine) to purchase equipment for: (1) a polymer lab to integrate new nanocellulose
fibers into composites; (2) structural testing for large-scale components; and (3) pilot
manufacturing of large-scale components (Table 1). The $3 million grant request from EDA
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Attachment A.2
will leverage more than $33 million of state, university and federal funding (Table 2), enabling
research that will have wide-ranging state, regional and national economic and environmental
benefits.
Table 1: Equipment List for AEWC Offshore Wind Laboratory Expansion.
Table 2: Funding sources and amounts for Offshore Wind Laboratory
Funding Source
Maine Technology Asset Fund (MTAF)
NIST
National Science Foundation –
Partnerships for Innovation
Maine Technology Institute
Department of Energy –
Industry/University Consortia
Amount
$4,999,460
$12,400,000
Department of Energy
$5,250,000
EDA
University of Maine
Total (not including EDA)
$3,000,000
$3,000,000
$600,000
$350,000
$7,100,000
Purpose
Brick and Mortar
Brick and Mortar
R&D for Floating Offshore Wind
Energy Platforms
Commercialization of Wind Energy
R&D for Floating Offshore Wind
Energy Platforms
R&D for Windblades and Floating
Offshore Wind Energy Platforms
Equipment
Match for Equipment
$33,699,4600
Leverage of EDA
Investment
Date Awarded
August 2008
January 2010
October 2009
Sept. 2009
February 2010
July 2010
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11.2:1
A.2.2 Scope of Work: Research Enabled by Equipment Acquisition
The equipment listed in Table 2 will foster both basic and applied research targeted at the
practical use of advanced composite and hybrid structures in the floating offshore wind
environment. Basic research activities will include advanced nanocomposite development and
characterization (section A.2.2.1). Applied research will include pilot-scale manufacturing and
testing of large structural components for offshore wind energy, including floating platform
components, towers, wind blades, and foundation and anchoring systems (sections A.2.2.2 and
A.2.2.3).
A.2.2.1
Advanced Nanocomposites Development and Characterization
The focus of this research is on development and application of nanocomposites to enhance the
design and performance of offshore wind structures. Weight reduction above the water level and
enhanced durability are the key research drivers. Nanoscale materials or nanomaterials have
been widely recognized to provide significant potential for the composites industry (Hussain et
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Attachment A.2
al, 2006). Potential product applications for these nanomaterials that have been envisioned
include building materials, composites for lighter weight automotive, wind energy and boat
applications, and “green” composite materials based entirely on renewable feedstocks (Park
2003; Thostenson 2002; Wong 2003; Xu 2003).
Nanomaterials refer to particulate, fibrous, or layered materials, with a diameter or thickness
measured in nanometers (10-9 meters). A primary advantage that nanomaterials bring to
polymeric composites is their extremely high ratio of surface area:unit volume (Hussain et al,
2006). Property enhancements achieved when adding nanomaterials to composites can include
mass reduction, increased stiffness, increased strength, electrical conductivity (e.g. electrostatic
dissipation, electromagnetic shielding), etc.
Several types of nanomaterials, including carbon nanotubes and clay nanoparticles have been
found to enhance the properties of both thermosetting and thermoplastic composites (Leong and
Varley, 2008; Luo and Daniel, 2003, Hussain et al, 2006). Recent commercial applications
include the new, lightweight sheet-molding compound (SMC) material NanoXcel™, developed
by the Yamaha Motor Corporation, USA. Winner of the JEC Group’s 2008 Innovation Award,
NanoXcel™ uses expanded nanoclay materials to replace calcium carbonate in composite
materials with a urethane matrix. Using this material in the decks and hulls of Yamaha
watercraft reduces structural weight by up to 25%, while adding significant strength.
In addition to investigating the use of conventional nanomaterials (such as carbon and clay) to
improve polymer composite properties, a significant focus of the proposed research will be on
methods of producing, processing, and characterizing new lignocellulosic nanomaterials.
Derived from renewable, inexpensive forest resources, ligno-cellulosic nanomaterials are a
potentially low cost, high value-added forest product that has been a subject of recent studies
at UMaine. A new initiative is underway at the University of Maine to extract lignocellulosic
nanomaterials from wood fiber. Nanofibers occur naturally in plants, as cellulose is synthesized
and aligned in stable bundles within the cell walls. Collaboration between three leading
interdisciplinary R&D Centers at the University of Maine – the AEWC Center, the Laboratory
for Surface Science and Technology (LASST), and the Forest Bioproducts Research Initiative
(FBRI) – is developing the science to sustainably produce cellulosic nanofibers from Maine’s
abundant wood resources, and integrate them into composite materials (Figure 2). Recent
collaborative research between the University of Maine and the University of Göttingen in
Germany suggests that carbonized woody residues could potentially be used for reinforcement in
polymer matrix composites; it was found that material containing greater percentages of either
carbon-black or carbon nanotubes would enhance the reinforcement potential (Pries et al, 2009).
Internationally, this is an active area of research with large-volume cellulose nanofiber
production efforts taking place in Sweden, Canada and Japan. The presence of these other
research programs supports UMaine’s focus in this area.
Utilization of lignocellulose nanomaterials in value-added composite applications requires that
their surfaces and interfaces be tailored to the specific material requirements of the application
(Renneckar et al. 2006). For example, incorporation of discontinuous fibers into a polymer
matrix for reinforcing purposes requires that the fiber surface be compatible with the matrix
since stress is transferred via shear along the fiber surface. Modification of the fiber/matrix
interface governs the critical length needed to transfer stress for a given fiber diameter (Batch
1997). Similarly, dispersion of nanofibers in a matrix or self assembly of individual fibers
requires control of interactions between the materials themselves and their environment.
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Attachment A.2
Therefore, the precise control of interface chemistry and functionalization to achieve desired
behavior for specific applications is crucial to composite applications of these materials (Gardner
et al. 2008).
Figure 2: Extraction of lignocellulose nanofibers from wood cell walls.
The surface functional groups, the surface potential, and the hydrophobicity / hydrophilicity of
lignocellulose-based nanofibers will be controlled during synthesis and/or processing by using
covalent or non-covalent means. The surface chemistry and resultant physical properties of the
different types of nanofibers vary considerably. For example, the surface moieties of electrospun
cellulose fibers depend largely upon the solvent used in the process and any chemical
modification or derivitization of the cellulose required to ensure dissolution (Hong and Kuo
2005; Bochek et al. 1997; Liu and Tang 2007). Conversely, cellulose nanowhiskers often have a
comparatively highly negatively charged surface due to the acid hydrolysis process typically
employed to produce them (Kotov et al. 2005; Chazeau et al. 1999; Araki et al.1998; Barzali and
De Souza Lima 2004). Covalent modification will employ either hydroxyl or other reactive
groups on cellulose via esterification, etherification, silanization, fluorination etc. (Sassi and
Chanzy 1995; Gousse et al. 2002: Grunert and Winter 2002; Kim et al. 2002; Andersen et al.
2006), or via activation processes such as oxidative treatments including ozone, plasma, flame,
irradiative or thermal processing. Non-covalent surface modification of lignocellulose will be
achieved via self assembly of surfactant or polymeric species from solution. The methodology
will use xylans and pullulans (Hedenberg and Gatenholm 2004; Renneckar et al. 2004) in
addition to cationic polyelectrolytes such as modified starch (Maximova et al. 2004).
In addition to employing the methodologies outlined above, research will include fundamental
studies probing alternate modifications via both covalent and non-covalent methods. The
proposed chemical reaction chamber system will be crucial. The assembled team members have
significant experience in self assembly of surfactants and polyelectrolytes at the solid/solution
interface, compatibilization of lignocellulosic materials in both thermoplastic and thermosetting
matrices, covalent surface modification of a vast array of organic and inorganic materials and the
production and characterization of nanomaterials including nanocellulose and nanocarbon.
The mechanical performance of composites is dependent on the degree of dispersion of the fibers
in the matrix polymer and the nature and intensity of fiber-polymer adhesive interactions
(Hussain 2006). The results of functionalization studies will be applied to specific matrix
polymers. Nanocellulose in composites utilizing thermosetting or thermoplastic matrices tend to
be facilitated through the use of solvent based systems including aqueous dispersed polymers,
i.e. latexes and organic solvent-based systems (Samir 2005). In addition, a number of researchers
are also utilizing melt processing techniques including extrusion and fiber spinning (Oksman
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Attachment A.2
2006; Kim 2005) for thermoplastic resin matrices. Successful large scale high shear melt
processing of nanocellulose in thermoplastic composites has yet to be realized, however, and
techniques to improve cellulose nanofiber distribution in thermoplastic and thermosetting
matrices need to be explored. Investigations of nanocellulose and CNT filled thermoplastic
composites will address three polymer matrix types including: polyolefinic thermoplastics such
as polyethylene and polypropylene, engineering thermoplastics such as polyamides (nylon) and
polyethylene terephthalate, and bio-derived thermoplastics such as polylactic acid and
carbohydrate-derived polymers. Research on nanocellulose and CNT filled thermosetting
composites will focus on vinyl ester, epoxy and phenol-formaldehyde resin systems. For offshore wind applications, it is envisioned that both thermosetting and thermoplastic polymer
composites could be applied for various wind energy component systems. The applications will
depend on strength, durability, lightness, fatigue resistance, etc.
A.2.2.2
Pilot Manufacturing of Large Structural Components for Offshore Wind
Energy
One critical research need is the development of advanced manufacturing processes (Griffin
2002), which can help reduce volatile (styrene) emissions, decrease the size and number of flaws
in large composite parts, and allow more optimal designs to be realized through the automated
control of fiber architecture. Research and development to improve manufacturing processes are
also important for the viability of the US composite manufacturing industry. In a panel
discussion at the 2007 Washington International Renewable Energy Conference (WIREC) in
Washington, D.C., Dr. Daniel Arizu, Director of the National Renewable Energy Laboratory
(NREL), reported that the increased demand for windblades is driving the price significantly
higher, and that US windblade manufacturers will be competitive with foreign suppliers if they
can achieve a productivity increase of 30%.
While some wind turbine blade manufacturers still use open-mold wet lay-up methods, due to
increasingly stringent environmental regulations and labor requirements these have been largely
supplanted by various resin infusion techniques and the use of pre-impregnated materials (Griffin
and Ashwill 2003). A particularly promising automated process is tape-laying, which is widely
used by the aeronautics industry because of its ability to produce higher-quality parts with fewer
fabrication inconsistencies while greatly reducing costs associated with hand labor. Tape-laying
requires of a spool of composite tape pre-impregnated with a thermoset or thermoplastic resin
and a highly automated machine that distributes the material to a predetermined layup or ply
schedule. The machine has the ability to repeatedly place the reinforcement with a high degree of
accuracy. The material is placed in an additive process via the automation upon a mold or
formed surface that is in the shape of the end product.
Assessment of cure processes, heat transfer and the effects of processing control on the end
product are active areas of research (Lu et al. 2005; Sun et al. 1998, 2001; Tumkor et al. 2001;
Yardimci et al. 2000), and the design of a robotic tape-laying device for a specific application is
a substantial effort. Key processing characteristics to be identified and addressed in design are
the time-temperature-tack relationship of the material, necessary consolidation pressures, and the
rate at which the thermoplastic polymer re-crystallizes after heating.
Under an existing collaborative research effort with leading companies in the fiber, fiber sizing,
resin, and automated manufacturing fields (PPG Industries, Zoltek, MAG-IAS, and Polystrand
Inc.), as well as Sandia National Lab, AEWC will develop robotic composite fabrication
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Attachment A.2
equipment that will enable us to produce prototype structural components with continuously
variable layups that are optimized for complex wind blade geometries and stress states. This
automatic tape-layup device will be designed specifically for fabrication of wind blades and
other large composite parts for the offshore wind industry. MAG-IAS is a leading supplier of
composite tape-layup equipment for the aeronautics industry, including the equipment used to
produce the fuselage for the Boeing 787 Dreamliner, and possesses the in-house engineering
expertise necessary to design the proposed tape-layup robot to our specifications.
A.2.2.3
Testing of Large Structural Components for Offshore Wind Energy
Floating platform technology for deep-water offshore wind is
currently being developed by several private companies,
including StatoilHydro (www.statoilhydro.com) of Norway (see
Figure 2). The AEWC Center has been actively working with
these companies, and in September 2009 was designated a
national center for Deepwater Offshore Wind Energy
Research by Secretary of Energy Steven Chu, with his
announcement of a $7.1 million award to fund the
DeepCwind Industry/University Consortium led by AEWC
(see section A.3.c for an overview of DeepCwind Consortium
R&D Plan). Through research at the AEWC Center, it has
become clear that floating platforms can benefit significantly
from the greater durability and lighter weight of composite
materials in at least parts of these structures.
Large composite parts envisioned for use in the construction of
Figure 3: Statoil Hywind floating
offshore wind turbine, deployed in
floating offshore wind generation facilities include platform
Sept 2009
components, towers, foundation elements, and windblades. These
structural components must possess service lives of 20-30 years in a harsh marine environment
while sustaining extreme dynamic and fatigue loads.
A fully equipped prototyping and testing facility with the ability to examine the full-scale
response of large composite structural components under monotonic and fatigue loading as
envisioned in this equipment acquisition proposal is critical for evaluating new designs and
materials. The structural testing equipment will allow the development of integrated
experimental programs that permit the assessment of static strength, dynamic response and
fatigue resistance from the coupon scale through the full-scale testing of wind blades and
structural components up to 70 m long.
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