What is the environmental impact of wind turbines whose blades have multiplied by almost the entire country?

Unlike traditional power plants, the great advantage of these huge modern mills is that they provide clean energy from simple wind, cleanly, and leave hazardous waste. However, this does not remove that, throughout its life cycle, also cause various types of conditions on the environment. http://thechemistrysideoftheforce.blogspot.com/

Before getting to spin its blades to generate kilowatt clean, will have been necessary to manufacture different parts, transport and assemble in place. And that means transforming resources, generate emissions and use other energy not so clean, ie pollution. How soon these machines to produce the energy that has cost manufactured and assembled? Not long: 153 days.

This is at least what felt Eduardo Martinez House, head of R & D in Group Wind Riojanas and associate professor of Mechanical Engineering at the University of La Rioja, from cycle analysis (LCA) of a wind turbine Gamesa G8X two-megawatt (MW) installed in the wind farm Munilla (also in La Rioja). Considering that this machine has a lifespan of 20 years (guaranteed time generally by manufacturers), this means that before the hypothetical decommissioning will have generated 47.4 times the energy needed for its manufacture. This is rather more than is achieved with a few solar panels, it is estimated that one of these solar installations produced in its 30 year life about 16 times the energy used in its creation if it is in Seville, 15 times if in Madrid and 13 times if you are in Barcelona (1).

By later this researcher of La Rioja has continued working on new studies to provide greater precision to these results. One of the factors that can change the environmental impact of these machines is wear suffering and maintenance to be performed. "Not that they have to change many parts, but these are very big," Martinez said House, who has analyzed the increase in the impact may be somewhat offset by the repair and reuse of components. "A shovel weighs around six tonnes, suppose that during the 20-year life of the machine must be changed once the complete rotor breakage of the three blades. That means re-build three blades, they are reassembled in the wind and send to landfill the old. "

In a wind of 70 meters high and 80 meter rotor, usually the party with the greatest impact are the blades and the foundation. Another key factor that can alter the environmental balance in the turbines is what happens to each of its components to become waste. Unlike the tower, whose steel can be recycled, hence the most problematic component is the rotor, the blades, which are made of a composite blend of fiberglass and epoxy resin (in the larger blades are also used carbon fiber .) Although not yet spent enough time so that no wind farm reaches the 20 years he estimated could reach the end of his life and there are no experiences of decommissioned plants, it is going to be replaced paddles damaged. And so, the fate of this piece, today, is the landfill. However, as calculated Martínez House, which could be recycled this component would reduce the overall impact of the wind at 6%. It may not seem a very high percentage alone, but as the researcher, suggests the importance of recycling every piece for the entire wind turbine.

In the analysis methodology Life Cycle used by this teacher of La Rioja include the effects related to impact categories standardized as ecotoxicity, land use, fossil fuels, climate change, carcinogens, ozone layer ... However, no takes into account a number of environmental impacts that are most important may have a wind turbine, is the case of visual pollution or damage to the birds.

As regards the impact on the landscape, it is often difficult to measure because it is a factor quite subjective. Still, it seems clear that can be increased by increasing the number of wind farms that are already 20,000 MW marked as a target for 2010. The trend is to place less wind, but larger.

As to the bird mortality caused by the blades of these machines there are many studies with very different results. What is the real impact of these turbines? "I can not say or whether high or low, depends very much on the location, may be zero or very large," says Manuela de Lucas, a researcher at the Department of Ethology and Biodiversity Conservation of the Biological Station of Doñana, which almost 15 years studying this problem.

As specified, the species most affected is the griffon vulture, as their way of flying is just to plan with the wind. According to the predictive model developed, rather than the proximity to the populations of these birds, the damage of wind turbines appear to depend on which are placed in currents of air used by these animals to move. "There are rows of wind turbines kill a lot and others only a few meters and do nothing," he says.