Wind Energy
Research
Wind energy
is a clean, domestically produced renewable energy resource that
contributes to our nation's security, improves its environmental
quality, and stimulates rural economic development. By the end
of 2008, the U.S. wind industry had become one of the fastest
growing utility-scale energy resources in the nation. With a current
annual growth rate of 30% to 40%, the nation's wind energy capacity
increased from 2,500 MW in 1996 to more than 21,000 MW at the
end of 2008.
Although 21,000
MW is enough capacity to power about 5 million average homes,
it still comprises less than 2% of our nation's generation portfolio.
In 2008, the U.S. Department of Energy published a report that
examines the feasibility increasing our nation's wind capacity
to more than 300,000 MW to produce 20% of our electricity demand
by 2030. The report concludes that although 20% wind energy by
2030 is technically achievable, it will require research and development
efforts to help increase wind energy system reliability and operability,
improve manufacturing processes, address transmission and grid
integration issues, mitigate siting and environmental issues,
and expand the wind energy market.
To expand
wind energy's contribution to the nation, the Wind Energy Program
focuses its research in two primary areas:
- Increasing
the technical viability of wind systems, and
- Increasing
technology application or the use of wind power in the marketplace.
Large Wind
Technology
Large wind
turbine research improves the commercial viability and supports
greater deployment of wind energy by improving the reliability
and performance of existing technology, while setting the stage
for future wind technologies advanced through applied research
and market assessment. This page describes the highlights of the
Wind Energy Program's research in this field.
Goal
The Wind Energy
Program's goal is to reduce the cost of electricity for large
land-based wind systems in Class 4 winds (5.8 m/s at a height
of 10 m) to 3.6 cents per kilowatt-hour (kWh) by 2012 and offshore
systems in Class 6 winds (6.7 m/s at a height of 10 m) to 7 cents/kWh
by 2014.
Wind turbines
are currently capable of producing electricity at 5 - 8 cents/kWh
in Class 4 wind regimes across the United States.
Research
Project Highlights
These are
some of the key research project highlights from the Wind Energy
Program's research in large wind technology.
Prototype
Development
During the
past two decades, the Wind Energy Program has worked with industry
to develop a number of prototype technologies, many of which have
become commercially viable products. One example is the GE Wind
Energy 1.5-MW wind turbine. At the end of 2007, GE had more than
6,500 of these machines installed worldwide. The design of GE's
1.5-MW machine is based on work conducted with GE and its predecessors
(Zond and Enron). Since the early 1990s, the program worked with
these companies to test components such as blades, generators,
and control systems on the various generations of machines that
led to GE's 1.5-MW workhorse. Another project that is demonstrating
commercial success is the new 2.5-MW wind turbine manufactured
by Clipper Windpower. Clipper produced a prototype of its 2.5-MW
Liberty wind turbine in 2005 after only three years of cooperative
research and development work with the Wind Energy Program. The
company installed 170 MW of its 2.5-MW machine in 2007.
Component
Development
The Wind Energy
Program also works with industry partners to improve the performance
and reliability of system components. Knight & Carver's Wind
Blade Division in National City, California, worked with program
researchers at Sandia National Laboratories to develop an innovative
wind turbine blade that the company expects to increase energy
capture by 5% to 10%. The most distinctive characteristic of the
Sweep Twist Adaptive Rotor (STAR) blade is a gently curved tip,
which unlike the vast majority of blades in use, is specially
designed to take maximum advantage of all wind speeds, including
marginal speeds. The blade was tested for endurance at the National
Renewable Energy Laboratory in 2008.
To support
the development of more reliable gearboxes, the program has worked
with several companies to design and test innovative drivetrain
concepts. Clipper's Liberty wind turbine incorporates a highly
innovative multiple-drive path gearbox that feeds four advanced
permanent-magnet generators. Global Energy Concepts (GEC) fabricated
a 1.5-MW, single-stage drivetrain with a planetary gearbox and
a medium-speed (190 rpm), permanent-magnet generator that shows
potential for reducing tower-head weight and drivetrain costs.
Northern Power Systems (NPS) constructed a permanent-magnet generator
with a novel power converter to allow variable-speed operation.
The NPS converter was chosen by the American Wind Energy Association
for its 2006 Technical Achievement Award.
Distributed
Wind Energy Technology
The Wind Energy
Program's Distributed Wind Technology research is working to meet
growing consumer demands for small turbines (up to 100 kilowatts)
for residential and small business applications; mid-sized turbines
(100 kilowatts to 1 megawatt) for farms, ranches, and small industry;
and locally owned community projects using larger turbines tied
to distribution lines. This page describes the program's distributed
wind energy research goals, activities, and some of its recent
project highlights.
Goal
The goal of
the program's distributed wind energy activities is to expand
the number of distributed wind turbines (1 kilowatt or larger)
deployed in the U.S. market fivefold from a 2007 baseline (2,400
units). Activities to support this goal include providing technical
support and independent testing of small turbines to ensure good
credible and reliable products are available in the United States
market.
Research
Project Highlights
These are
some of the key research project highlights from the Wind Energy
Program's research in distributed wind energy technology.
Independent
and Testing Activities
To help industry
provide consumers with more small wind turbine systems certified
for safety and performance, the Wind Program launched an independent
small wind test project in 2007. The primary objective of this
activity is to test commercially available small wind turbine
systems that have a high probability of success in the U.S. market
over the next several years. The availability of reliable small
wind turbines will support the program goal of increasing the
number of small wind turbines installed in the United States 5-fold
by 2015.
Prototype
Development
The Wind Energy
Program has worked with several small wind industry partners to
develop commercially available award-winning small and mid-sized
wind generation systems. In 2000, DOE's National Renewable Energy
Laboratory (NREL) received and R&D 100 Award for its contribution
to the development of the Northern Power Systems (NPS) NorthWind
100/20 wind turbine. The NorthWind 100/20 wind turbine is a state-of-the-art
wind turbine designed for operation in remote, cold-climate conditions.
By the end of 2007, 11 of these turbines had been installed and
10 more were sold and awaiting installation. Since then, NPS has
reconfigured its 100-kW cold weather turbine for agricultural
and community applications in temperate climates. The company
began testing its new prototype at the NREL in 2007.
Southwest
Windpower has been working with the program for the past several
years to develop a 1.8-kW wind energy generator called the Skystream.
In 2006, Southwest Windpower received a Best of What's New Award
from Popular Science for its new wind generator, and it was recognized
by Time Magazine as one of the "Best Inventions 2006." Since the
company began commercial production of the Skystream in 2007,
it has sold more than 1,000 units.
The program
also worked with Windward Engineering to design and test a 4.25-kW
machined called the Endurance. The company began commercial production
of the machine in 2008.
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