One of the most promising alternative-energy technologies has, in recent years, garnered more skepticism than praise. Horizontal axis wind turbines (HAWT), those massive, bladed towers that turn a windy day into clean energy for the grid, can also kill birds and bats, require expensive regular maintenance, have issues with efficiency and just generally annoy local residents with suddenly hindered views and undesirable (and possibly unhealthy) noise levels.
U.S. wind-farm installation has accordingly slowed, but an influx of government funding in 2012 may offer new hope for wind power [source: Hurdle]. Research has been yielding some amazing possibilities in features and generation methods; a lot of the machines on the drawing board look and function very little like the "windmills" we're accustomed to.
The future of wind may not be in blades, in farms, or even fixed to the Earth. Here are 10 of the most unique approaches to improving the ways we turn wind into electricity. Some are a wee bit dreamy, others in various stages of design and prototype, and a couple boast tentative dates for commercial sale.
We'll begin with one whose inventors say captures far more wind than conventional designs and may be on the market in 2013.
Collecting It First
Omni-directional has been done, with adjustable turbine blades mounted in traditional, vertical orientation that can move to accommodate directional change. The IMPLUX goes another way with the method, funneling air from multiple directions into a vertical-axis set-up.
The inventors at Katru have, in their working model of a rooftop wind turbine for small-scale energy production, created a device that captures more wind by collecting it before it hits the turbine blades [source: Yirka]. A round, slatted chamber acts as a 360-degree intake structure that takes wind traveling from all directions and re-directs it in just one: upward, to horizontally spinning blades (a helicopterlike orientation).
Because the turbine is enclosed, and the enclosure's slats are spaced close together, it poses no danger to birds and produces very little noise compared to current turbine forms [source: Katru Eco-Inventions].
IMPLUX would be mounted atop buildings to capture the relatively untapped energy flowing over urban centers. The latest model is just 9 feet (2.7 meters) tall and rated at 1.2 kilowatts; Katru's plan is to up that to a 6 kilowatt maximum by the end of 2013, when the IMPLUX is slated for commercial availability [source: Katru Eco-Inventions].
Next, on a whole different level ...
Sending It Up
Way, way above the ground, there's enough wind energy to power 50 globes, according to industry group Alternative Energy [source: Alternative Energy]. These high-altitude winds, historically beyond the reach of our technology and science, could be on the verge of feeding our grids.
Several companies are designing airborne turbines that would float thousands of feet in the air, converting high-altitude winds into electricity. Designs range from kite-type structures to blimps, essentially flying turbines that would capture wind, convert it to electrical power, and send it down to Earth by way of a tether.
Safety concerns abound, another reason why flying turbines have been a back-burner dream [source: Alternative Energy]. The Federal Aviation Administration has advised a limit of 2,000 feet (600 meters) for such structures, to avoid interference with air traffic, and designers have to prove that they can land their turbines safely should a tether fail or extreme weather cause other malfunctions.
High-altitude turbines are in various stages of development. They haven't yet been tested at the high altitudes for which they're intended [source: Alternative Energy].
Next, Tesla enters the picture.
Starting with the Tesla Engine
Inspired by an engine design patented by inventor Nikola Tesla in 1913, a company named Solar Aero has designed a wind turbine with no blades, a small footprint and, according to the designers, low enough maintenance costs to bring the price of its electricity down to coal-fired rates [source: Zyga].
The Fuller turbine uses thin metal disks to turn a generator. The airfoil-style disks are closely spaced and angled such that when wind flows through the unit, they spin, regardless of the direction or strength of the wind. Because the number of disks can be increased or decreased to achieve different power outputs and sizes, the Fuller turbine can be easily adapted to accommodate a wide range of locations.
Easy access to the disk-and-generator setup, along with reduced height requirements since blade clearance is not a factor, mean lower maintenance costs, according to Solar Aero. The removal of blade clearance from the equation also means the units can be placed closer together, so 20 Fuller turbines would require less land than standard, bladed machines [source: Zyga].
Like many other innovations on this list, the Fuller turbine takes birds into account: The entire moving system is screened in.
Next, another engine acts as muse.
Starting with a Jet Engine
A subsidiary of aerospace manufacturer FloDesign has taken the jet-engine concept into wind energy. The FloDesign wind turbine is smaller than current turbine structures but can, according to its inventors, produce up to four times more power [source: LaMonica].
Much like a jet engine, FloDesign has a set of fixed blades that sit in front of the moving turbine blades. They are spaced and angled to take advantage of variations in wind speed to produce a rapid-mixing vortex -- a vortex that sucks in additional wind (which would be missed by typical turbine designs) and speeds it up [source: Bullis]. It is this greater volume of faster-moving air that hits the movable blades, spinning the generator.
The unit's designers say FloDesign can produce as much energy as a HAWT unit twice its size [source: Bullis]. In 2011, the unit was installed on an island in Boston Harbor, and it performed well [source: Watt Now].
Next, eliminating friction ...
One of the reasons why wind turbines are relatively inefficient is the friction between moving parts [source: Fecht]. That friction wastes energy, reducing the turbine's output. If you could, say, levitate a turbine's blades rather than physically attaching them to the base, that friction would be eliminated.
This technology is available. Several companies, in various stages of development, are working on maglev turbines. Magnetic levitation, which has propelled clean-energy trains for years, has the potential to increase wind-turbine efficiency by up to 20 percent, according to China-based Guangzhou Energy Research Institute [source: Fecht]. These frictionless units can harness slower-moving wind, turn more of the wind power they capture into electricity, and face less wear-and-tear than traditional models.
U.S.-based Regenedyne and NuEnergy are both developing maglev turbines for commercial sale. The models are silent, safer for birds and are significantly less expensive than "windmill"-type units [source: NuEnergy]. Lifespan would have a lot to do with that: Regenedyne claims a maglev-turbine lifespan of 500 years, compared to about 25 years for current, friction-filled models [source: Off Grid Technologies].
Next up, wind energy goes recreational ...
Wandering in It
City planners in Abu Dhabi imagined a futuristic community in which clean energy would be more than energy; it would be enjoyed. Design firms submitted proposals, and a company in New York won first prize for its concept of a field of reedlike turbines that move in the breeze like stalks of wheat.
Atelier DNA envisioned slim, graceful turbines called Windstalks. Each LED-lit, 180-foot (55-meter) stalk sways in the wind, creating kinetic energy to drive a torque generator [source: Danigelis]. A slim, bladeless design allows for close spacing, safety for birds and bats and, most uniquely, a lovely evening stroll: Designers hope residents will one day take walks through a farm of swaying Windstalks, experiencing clean energy as something like art.
The idea turns the wind farm into a visually enjoyable installation, rather than one to put up with in the name of clean, renewable power. It's an innovative way of removing one of the loudest objections to wind farms today, imagining instead the possibility that in the future, people might actually want to live near acres and acres of turbines.
Next, calling on one of the oldest, most efficient ways to capture the power of wind ...
Starting with a Sail
One of the oldest ways to capture wind energy is the sail. Since the very first shipbuilders erected a mast, the simple sail has harnessed more of the kinetic energy in wind for human use than any other structure [source: Zaghdoud].
Sail as inspiration for a high-efficiency wind turbine, then, makes perfect sense, and Saphon Energy hopes to implement it in a sail-shaped turbine it calls Saphonian. Compared to a standard, bladed design, the more aerodynamic, lower-friction turbine can use up to twice the amount of energy in a given supply of wind, using it to create hydraulic pressure to drive a generator [source: Zaghdoud]. According to Saphon, its most recent prototype is more than twice as efficient as a typical windmill-style turbine [source: Zaghdoud].
As an interesting side note, Saphonian takes its name from Baal-Saphon, a wind deity in the religion of ancient Carthage. In particular, Baal-Saphon ruled the wind that would churn up the seas, and he was worshipped by Carthaginian sailors on their journeys [source: Saphon].
Next, at the blade's edge ...
Wear-and-tear is a serious issue in wind turbines, because repeatedly replacing expensive parts increases the cost of the power they generate. The Risø National Laboratory for Sustainable Energy in Denmark is taking on one of the greatest wear-and-tear culprits: the extraordinary load placed on turbine structures when their massive blades rotate [source: Alternative Energy].
To reduce that load, Risø researchers have devised a different kind of blade -- or at least a different kind of edge for it. They believe that a trailing edge that can bend while the blade rotates, creating a smoother flow of air off the blade, will dramatically reduce the load on the support structure [source: Alternative Energy].
Researchers point to the flaps on airplane wings as an example of the concept: Those flaps alter the wing's shape to offer increased control over lift forces during takeoff and landing. A rubber trailing edge, through similar means, could increase the stability of spinning turbine blades, reducing the amount of stress on the components holding them [source: Alternative Energy].
Risø's flexible edge is still in the research and design phase.
Next, a new way to do it offshore ...
Shifting the Weight
Offshore wind farms offer huge potential in wind power, but potential drawbacks make their future uncertain. One of the greatest concerns is financial, especially regarding the cost of anchoring a wind turbine to the ocean floor. That price of that construction is so high as to raise doubts as to the viability of large-scale offshore power generation.
Many companies are looking for ways to decrease that cost. One of them, Technip, went at it from a center-of-gravity angle, turning the traditional turbine structure on its side. The effect is a structure that's more stable: The Vertiwind design moves the generator, the heaviest component, closer to the ocean's surface -- 65 feet (20 meters) above the sea, rather than the usual 200 feet (60 meters); it also makes the axis of rotation vertical [source: Gatto]. The combined result is a lower center of gravity that reduces the depth and complexity of anchoring requirements [source: Snieckus]. Ideally, Vertiwind turbines will not need to be fixed to the ocean floor at all.
As of January 2013, a 35 kilowatt Vertiwind prototype is ready for testing off the coast of France [source: Wind Power Intelligence].
That's not, apparently, the only way to go about it, though. One final wind-power innovation proposes another solution to high offshore costs.
Wind-power collaborative WindPlus is also working on the anchoring issue. In this case, though, the turbine keeps its horizontal axis, like you see on most land-based structures; the big development here is a support system called WindFloat.
WindFloat is a semi-submersible platform held in place by a drag-embedment anchor. In drag embedment, there's no construction at the seafloor. Instead, an anchor is dragged along the floor until it embeds itself at the desired depth. The drag-anchored platform supports an offshore turbine like the ones commonly in use now. WindFloat can potentially allow the affordable installation of larger turbines than those producing offshore power now.
This floating-turbine design allows not only for lower installation costs but also lower assembly costs, since the entire setup, both platform and turbine, can be assembled on land. Current technology relies on assembly at sea, which involves far more unstable and logistically complex conditions [source: Macguire]. WindFloats are already in use off the coast of Portugal, and, as of December 2012, plans for installation off the coast of Oregon are moving forward [source: Recharge].
That Oregon project has been green-lighted in part by new development grants from both the European Union and the United States [source: Recharge]. New government funding for wind power, particularly the offshore variety, issued at the end of 2012 could mean big leaps in development. Hopes are that with the money to perfect design and implement more real-world testing, innovations like these could dramatically increase the viability of wind as a significant source of affordable, clean energy.
We're pulling CO2 out of thin air and transforming it into a fuel. HowStuffWorks looks at the science and how close it is to commercial viability.
Author's Note: 10 Innovations in Wind Power
There are countless innovative minds working to improve the performance of wind turbines, but here, I had to choose 10. There are so many out there, some heavy on adjustments for mechanical efficiency, others concentrating on eliminating "eyesore" issues and environmental damage, and many addressing both. I chose these particular innovations because I found them to be especially unique or surprising, or their bold claims have actually been borne out in field testing.
Each listed innovation, as well, may turn up in the work of more companies than I was able to include here. It's amazing how many inventors hit the same mark.
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