By now, wind power is an established source of
clean energy — and a visible one. But after a generation’s worth of wind
turbines turning across fields and towering on floating platforms off our
coasts, a collateral challenge is posed:
What to do with the risk of
accumulating waste as wind power infrastructure grows old?
More and more of the massive turbine structures are reaching the end of their
typical 20-year lifecycle, and the need to solve the mounting of waste is
becoming urgent. While about 85% of turbine materials are recyclable, the
blades themselves, requiring both strength and agility, are made from materials
like glass fibers, resins, and foams — substances that are generally
non-biodegradable and much more difficult to recycle.
As companies around the world are sprinting to manufacture more sustainable
blades and greening their production processes, others are finding creative
ways to make use of the thousands of turbines that come out of service every
year:
Urban
repurpose
design Under a project entitled “Re-Wind,”
an interdisciplinary, multi-country research team comprising experts from City
University of New York, Georgia Institute of Technology, University College
Cork and Queen’s University Belfast are coming up with smart alternatives to
unsustainable disposal methods such as landfill and incineration.
The Re-Wind team explores the
blades’ potential reuse in architectural and engineering structures, by turning
them into protective bike shelters, or pedestrian bridges. In the port of
Aalborg, Denmark, where wind power already provides 40% of the national energy
demand, the network has constructed an unusual bicycle garage, made from actual
wind turbines that were once in use.
- In Ireland, the Cork Institute of
Technology is working on recycling three recently decommissioned wind turbines
from a Belfast farm. So far, several proposals have been considered field tests
are underway — including repurposing the blades in skate parks, stadium
bleachers, or sound barriers.
Waste-to-energy
In northern Germany, a waste management company has found
a way to fuel a cement plant with decommissioned turbineblades.
- The method, pioneered by waste
management solutions company Geocycle, starts at the wind farm where the blades
are cut into 10-meter pieces and transported to a pre-processing plant. There,
the blades are shredded into smaller pieces and the metals are separated by
magnet. Finally, the crushed blade dust is mixed with a humid substrate
material made of other residues such as packaging waste in order to bind
together the blade dust.
- At the cement plant, the
waste-to-energy procedure is based on a dual process where the organic content
of blade waste is recovered as thermal energy and the mineral fraction
(resulting from the grinding of glass fibers) partially replaces the sand and
carbon clay needed to make cement. The result is a 27% reduction in CO 2
emissions and a 13% reduction in water consumption.
- So far, the LafargeHolcim group
cement plant in Lägerdorf, Germany, is the only plant in Europe where this
waste-to-energy technology has been implemented.
More
efficient turbines
As the life cycle of turbines
installed at Scotland’s Windy Standard farm will reach its end in 2027, the
owner Fred Olsen Renewables is looking to both replace the old structures with
new ones as well as recycle and repurpose the decommissioned materials.
- While the farm’s planning
conditions stipulate that all the original turbines should be removed and the
land restored to its former condition after being in operation for 25 years, theowner hopes to "repower" the site - removing the existing
turbines and replacing them with new, more powerful machines, using existing
tracks and infrastructure on the hillside.
- Currently, 36 turbines produce
enough energy to power 16,000 homes. But with improved technology, doubling the
power output would only require nine new structures — which could be three
time taller than the existing ones.
- While the Windy Standard turbines
are made from 75% recyclable material, each tower has three 16.8-meter blades
which cannot easily be recycled. Therefore, the firm is looking for inspiration
from the Re-Wind network, as it also plans to turn old turbines into public
seating, wind breaks and pedestrian bridges. It has also been suggested that
some of the turbines be donated to universities to help train turbine
technicians of the future.
Recyclable
blades
Spain-based Siemens Gamesa has taken wind-power
sustainability to the next level by pioneering
the world’s first fully recyclable turbine blade,
aptly named the RecyclableBlade.
- Just like traditional blades,
Siemens’ new structures are made by a combination of reinforcement materials
that are embedded in a resin to form a strong and stiff lightweight structure.
But the difference is the use of a new resin with a different chemical
structure, which makes it possible to dissolve the resin in an efficient
process at end-of-service life.
- In order to separate the composite
materials, the blade is submerged in a heated acidic solution for a few hours.
Therefore, acid rain has no effect on the blades, as the process will only take
place with both constituents there at the same time.
- Once broken down in the acidic
solution, the blade materials can be used in consumer goods, including
flat-screen TVs and suitcases. The company estimates that if its blades are
used on all new wind turbine schemes by 2050, 10 million tons of waste materials
could be saved from landfill.
ENGIE EYE
Elium-based
blades
In France, a cross-sector consortium including
ENGIE and French research center IRT Jules Verne has launched a project called ZEBRA withthe aim of manufacturing 100% recyclable turbine blades.- The broader goal is an end-to-end
sustainable solution for the full value chain, where automated manufacturing
will reduce energy consumption and waste, and new recycling methods will be
used to turn the prototype blades into new products.
- The project includes a new
partnership with specialty chemicals and advanced materials company Arkema,
that has developed a new type of resin (Elium) that will help the wind blades
become fully recoverable after a depolymerization process. Elium-based blades
also lowers energy consumption as it allows blades to be molded at a lower
temperature.
- The project, an ENGIE Innovation
Trophies 2020 winner, was launched for a period of 42 months with a budget of
€18.5 million.
Photo : SUPERUSE STUDIOS/Denis Guzzo)
