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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