feature: Wind energy update
Wind
Blades
PROgRess &
challenges
Despite double-digit wind energy industry growth, turbine blade manufacturers and
materials suppliers acknowledge a pressing need to reduce costs and innovate.
T
Source | Siemens
he past year was exceptional for the world wind energy
market, as wind-generated electricity continued to increase
its share of the overall electric power supply base. Te global
wind power industry grew about 16 percent in 2012, adding 45
GW of new capacity. Tis increased total capacity to 285 GW, or
about 2.62 percent of the world's electricity, according to statistics
published by online energy market news aggregator TeEnergyCollective.com. In the U.S., 6 GW of new capacity was installed in
2012, 19 percent more than in 2011. Wind turbines now account
for roughly 3.4 percent of all electricity generated in the U.S. With
the Jan. 1, 2013, extension of the federal Production Tax Credit, the
U.S. is expected to add 5 GW of wind-generated electricity this year.
Despite the ongoing expansion of wind power, the wind energy
industry's mandate to innovate has never been greater. Its ability to
compete with other renewable and nonrenewable sources of energy
and the continued growth and proftability of turbine manufacturers and suppliers depend on it. Areas of concern include better ways
to enhance not only the mechanical and aerodynamic performance
of turbine blades but also their weatherability and resistance to environmental elements. It is also incumbent on the industry to explore
ways to reduce the radar signature of wind farms — an issue that has
resulted in delays or cancellations of some farm installations. Last,
there is a sense of urgency about mitigating the cost of manufacturing, installing and metering wind turbines in anticipation of what
many experts predict will inevitably be
a subsidy-free, level energy playing feld.
Pushing Past the
efficiency Plateau
compositesworld.com
If the rotors of a wind turbine are not
turning, the turbine is not producing
electricity and its owners are not making
money. Tat fact feeds the perception
among critics that wind cannot compete
with on-demand power sources, such
as fossil fuels, nuclear and hydro. Tus,
one rationale for longer rotor blades is
that the longer the blade, the greater the
amount of time a turbine will spend in
service under variable wind conditions,
a metric known as capacity factor.
30
Pictured here is one-half of the mold
Siemens AG (Erlangen, Germany) is using to
build rotor blades for what the company says
will be the world's largest turbine, the SWT6.0-154. Its 75m/246-ft balsa-cored glass/
epoxy blades will be molded in one piece to
eliminate seams and bonded joints. A Danish
energy provider is planning to install about
300 of the turbines off the British coast when
testing is complete.