Wind turbines with retractable arms?
It’s simple, really: in general, large turbines harvest more energy from the wind than small ones, but that changes if the wind is too strong. Then long blades become a disadvantage as they exert big stresses on the turbine’s mechanism, resulting in possible damages.
Wind Turbines With Telescopic Arms?
What about a wind turbine with telescopic arms? Rajnish Sharma of the University of Auckland in New Zealand calculated that such a turbine could generate twice as much power over a year as an ordinary one, and be safe to run at high wind speeds. To test the idea, he built a prototype based on a small 1.5-kilowatt turbine. In strong winds it generated the same power as a standard turbine, while in gentler conditions it easily beat its rival.
From The New Scientist:
The extendable blades cost more to make, though Sharma calculates they would be cost-effective even if they were four times as expensive as ordinary ones. The blades could be deployed in areas once thought unsuitable for wind power, Sharma adds. And existing turbines could be retrofitted with the blades, though Sharma has not tested the idea on industrial-scale turbines.
Struggling To Prevent Bird Deaths At Altamont Pass Wind Farm
Since I drive past California’s iconic Altamont Pass wind farm often, I’m excited to hear about this new development.
For years, environmentalists have raised alarms about the slaughter of red-tailed hawks, golden eagles and other raptors that have fallen victim to the whirling blades of thousands of wind turbines along the Altamont Wind Resource Area. So this past summer, it got the beginnings of a major upgrade that promises to drastically reduce the number of bird deaths.
Nearly 2,000 of the 4,000 wind turbines in operation, many of which are nearly 30 years old, will be replaced over the next four years with about 100 huge state-of-the-art turbines that, at 430 feet, stand taller than the tallest coast redwood trees. For every new turbine installed, 23 of the old ones will be removed — a dramatic drop expected to significantly reduce the number of birds killed each year.
Shawn Smallwood, a renowned expert on birds and wind turbines, estimated that about 2,000 raptors are killed each year, along with as many as 8,000 other birds and bats. Young birds learning to fly are particularly vulnerable.
“Any way you look at the mortality data, there’s been a tremendous impact on birds,” said biologist Doug Bell, manager of the East Bay Regional Park District’s wildlife program. “I’ve found birds sliced in half. You see all kinds of blunt force trauma.”
Reducing Bird Mortality Rate By 80 Percent
So it’s great news that the Altamont Pass area will be repowered with taller mega-turbines that some say could reduce the bird mortality rate by 80 percent. At the same time, 6.5 miles of overhead electrical lines and about eight miles of road will be removed, allowing the land to return to a more natural state. The project also is creating union construction jobs: About 135 people have been hired.
This is an important milestone, but retractable wind turbine blades could be even more momentous. Let’s hope they become a reality.
Photo Credit: socialpyramid
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