MEXICO CITY, Mar 2 (Tierramérica) - With the blessing of development agencies, transnational corporations and environmentalists, the Mexican government is breaking ground for a big wind energy project. But peasant farmers and bird experts aren't too happy about it. The government's aim is for wind-generated electricity - which now accounts for just 0.005 percent of the energy generated in Mexico - to reach six percent by 2030. Achieving that goal involves setting up more than 3,000 turbines in Mexico's windiest zone, the Isthmus of Tehuantepec, in the southern state of Oaxaca, as well as several other wind farms around the country with dozens of turbines each. But erecting the windmills, tall towers with a 27-metre blade span, requires negotiating with landowners, most of whom are farmers. Some have complained that they were taken advantage of when the first wind farm was created in 1994. Meanwhile, bird experts warn that many species are at risk of being killed by the giant blades, which could cause an environmental chain reaction across the continent, because various are migratory species. "Everything is bent towards facilitating the wind farms, but there is not much interest in the birds, which in the long term could bring much broader problems," Raúl Ortiz-Pulido, spokesman for the Mexican office of the BirdLife International, told Tierramérica.
It's a given that anytime we post a story on wind power someone is going to comment that "turbines kill birds," suggesting that wind power may therefore be unacceptable. Compared to what? Hitting birds with automobiles (along with turtles, groundhogs, and deer)? Birds caught by feral cats? Birds colliding with buildings or phone towers? Quite possibly, a higher mortality will be attached to the transmission wires needed to get the wind power to market. Why, then, do many associate bird mortality only with wind turbines? We hope to get to the bottom of this "death by turbine" myth hole, and point to the factors that can actually be managed though public involvement. Our hunch is that the Altamont Pass California wind turbines, reportedly the site of some of the highest bird mortalities associated with any US wind farm, and using what is now an antique turbine design, are at the root of the widespread association of bird mortality with wind turbines in general. Now might be a good time to have a glance at this site, to get some perspective on the hundreds of raptors killed per year by the Altamont turbines. If extrapolating the "worst case" rate is a bad idea, what about the "average" wind farm bird mortality figures? Even average rates, which are much lower or course, need to be looked at carefully. To help our understanding of turbine hazards to birds we'd like to make an analogy, to your bicycle. Turn your bike upside down or put it in a work rack, set it to the highest gear...the one you use to go fast on a level slope.... and now move the wheel slowly with your hand. The chain moves rapidly with only a few degrees of wheel rotation. This symbolizes today's cutting edge 1.5 mW turbines, which have a very large surface area of blade exposed to the wind and a gearbox that turns the dynamo quickly while the blades move slowly. Birds dodge these slow moving blades relatively easily. Now put the bike in the lowest gear...the one you use to climb hills...and move the wheel with your hand fast enough to turn the chain as fast as before. That symbolizes the 20-year-old "bird-o-matic" wind turbine design. Small blades with small surface areas have to turn rapidly to overcome the magnetic force of the dynamos, which generate electricity. Recapping: small blades, low surface area, lots of dead birds possible; very big blades, with large surface area exposed to wind, very few dead birds.
It's a given that anytime we post a story on wind power someone is going to comment that "turbines kill birds," suggesting that wind power may therefore be unacceptable. Compared to what? Hitting birds with automobiles (along with turtles, groundhogs, and deer)? Birds caught by feral cats? Birds colliding with buildings or phone towers? Quite possibly, a higher mortality will be attached to the transmission wires needed to get the wind power to market. Why, then, do many associate bird mortality only with wind turbines? We hope to get to the bottom of this "death by turbine" myth hole, and point to the factors that can actually be managed though public involvement.
Our hunch is that the Altamont Pass California wind turbines, reportedly the site of some of the highest bird mortalities associated with any US wind farm, and using what is now an antique turbine design, are at the root of the widespread association of bird mortality with wind turbines in general. Now might be a good time to have a glance at this site, to get some perspective on the hundreds of raptors killed per year by the Altamont turbines.
If extrapolating the "worst case" rate is a bad idea, what about the "average" wind farm bird mortality figures? Even average rates, which are much lower or course, need to be looked at carefully.
To help our understanding of turbine hazards to birds we'd like to make an analogy, to your bicycle. Turn your bike upside down or put it in a work rack, set it to the highest gear...the one you use to go fast on a level slope.... and now move the wheel slowly with your hand. The chain moves rapidly with only a few degrees of wheel rotation. This symbolizes today's cutting edge 1.5 mW turbines, which have a very large surface area of blade exposed to the wind and a gearbox that turns the dynamo quickly while the blades move slowly. Birds dodge these slow moving blades relatively easily.
Now put the bike in the lowest gear...the one you use to climb hills...and move the wheel with your hand fast enough to turn the chain as fast as before. That symbolizes the 20-year-old "bird-o-matic" wind turbine design. Small blades with small surface areas have to turn rapidly to overcome the magnetic force of the dynamos, which generate electricity.
Recapping: small blades, low surface area, lots of dead birds possible; very big blades, with large surface area exposed to wind, very few dead birds.
