Wind turbines have 35-fold environmental benefit
RANDERS, Denmark, April 20, 2005 (Refocus Weekly)
A 3 MW wind turbine generates 35 times more energy during its lifetime than it consumes in production.
A lifecycle assessment of the V90 turbine manufactured by Vestas was
conducted to demonstrate the environmental advantages of a wind turbine on the
external environment throughout its lifetime. The lifecycle assessment included
the production phase of obtaining raw materials, transporting the turbine
components and erecting the unit, operating and maintaining the turbine
throughout the 20-year design lifetime, and then disposing of the turbine.
“The lifecycle assessments are used as a natural and important decision-making
tool in product development and in the choice of production technology,” says
Vestas president Svend Sigaard. “With lifecycle assessments of our wind
turbines, we have an excellent tool to compare the products and estimate how big
an advantage our wind power systems are to the environment.”
Vestas intends to conduct lifecycle assessments on all of its turbines.
The 3 MW offshore turbine must generate electricity for 6.8 months before it has
produced as much as it’s used during its design lifetime. Compared with the 2
MW offshore V80 turbine, the 6.8 months is an improvement of 2.2 months.
In a good site, the V90 will generate 280,000 MWh over 20 years, displacing the
net emission of 230,000 tons of CO2 compared with a coal-fired power station.
In 2004, Vestas delivered 2,784 MW of turbine capacity, and the annual output
from these units would serve the needs of 2.1 million Danish homes. The turbines
would also displace the emission of 4 million tons of CO2, compared with the
average electricity generated in Europe, based on the average emission of 548
grams of CO2 per kWh of output from facilities across the continent.
“Preparation of raw materials and resources for the wind turbine and the
production processes themselves has a negative impact on the environment,” but
the energy generated by the turbine and a high percentage of turbine materials
can be reused, the company explains. For the V90, 80% of an onshore turbine on
an 80 m tower can be reused, it notes.
“Electricity production in relation to resource consumption is seen as the
most important aspect of both offshore and onshore wind power plants, ie: a 50%
increase of the electricity production will result in a 50% decrease of the
energy balance,” it concludes. “Furthermore, the disposal stage and
especially the recycling of metals are also contributing to the environmental
profile. Environmental impacts from the transport stage and the operation stage
are not considered significant in relation to the total environmental impacts of
both the offshore and onshore wind power plants.”
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