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In a few years, you may see scores of giant blimps floating overhead. But it won't be because Goodyear is having a hoedown -- those blimps are actually wind turbines. They're not your typical turbine, though. These extremely mobile energy generators, christened with the acronym MARS, will float high in the air at altitudes ranging from 600 to 1,000 feet (183 to 305 meters). The MARS acronym -- not to be confused with the red planet -- stands for Magenn Air Rotor System, and its concept is actually pretty down to Earth. The turbine's only relationship to outer space is the fact that it slightly resembles an oddly shaped UFO.
Why a floating turbine, you ask? Magenn originally designed the turbine for locations where setting up a traditional wind farm isn't realistic: places with a harsh climate like an Antarctic research station or disaster areas that need quick access to power for emergency and medical equipment.
But although the inventor of the MARS turbine designed it mainly for remote areas and didn't intend for it to compete with conventional turbines in the current wind turbine market, it's difficult not to compare the two. Despite the improvements in conventional wind turbines over the years, they've encountered their share of opposition and have had a rough time catching on. While the current 100,000 megawatts of electricity generated worldwide by wind is impressive, it only accounts for a small percentage of the world's total electricity production.
With the introduction of new wind-energy turbine designs like the one used in the MARS, however, that statistic could soon change. Although the basic concept behind it is the same as that behind traditional wind turbines -- the conversion of one form of energy (wind energy) into another (electricity) -- the MARS turbine possesses several differences that could make it appeal to a wider market. One of those differences is that it doesn't rely on a large tower to hold it up. It's simply attached to the ground by a strong tensioning cable called the tether. But the differences don't end there.
Find out how this turbine, which the CEO of Magenn characterized as a floating white sausage with paddleboat wheels, compares to conventional turbines on the next page.
MARS: Taking Wind Power to a Higher Level
At the most basic level, generating electricity from the movement of wind is straightforward. You can learn about the process in more detail in How Wind Power Works, but the simple version is that wind spins a turbine's blades, which, in turn, cause an attached generator to also spin. The generator then converts that moving energy of the wind into electricity using electromagnetic induction, which involves using the opposite charges of a magnet to create an electric current.
Instead of the large pinwheel blades that are typical of wind turbines though, the blades of the MARS turbine are actually part of the three-dimensional blimp itself. The blades catch the wind, causing the entire blimp to spin around. After the generator converts that movement into electricity, it's transferred down the turbine's long tether.
Whereas most regular turbines capture winds at altitudes of 200 to 300 feet (61 to 91 meters), the MARS turbine can reach winds from 600 to 1,000 feet (183 to 305 meters) above ground level. Winds at these higher levels are significantly faster than low-level winds because they don't encounter as much resistance from objects on the ground like trees and buildings. Research shows that with each doubling of elevation, there is a 12 percent increase in wind speed; with each doubling of wind speed there is an eightfold increase in wind power [source: Layton].
Along with its potentially large power output, the tethered, inflatable MARS is also easy to deploy. Constructing and installing conventional wind turbines is a major endeavor often involving foundation blasting and the transport of heavy equipment. Digging up the ground may promote erosion in some areas, while removing trees and otherwise disrupting pristine environments can create fragment habitats and disturb entire species. When you consider that a modern wind turbine has rotor blades that weigh thousands of pounds a piece and are larger than a Boeing 747, you can see that setting one in the ground is no small task [source: American Wind Energy Association]. Understandably, many people are opposed to wind farms for these very reasons.
The MARS turbine, on the other hand, avoids all that. It's simply kept aloft by a lighter- than-air gas like helium. By now you can probably see how the MARS could elevate wind energy to new heights. Learn more about the design of this otherworldly turbine on the next page.
Magenn Power designed its turbine not only for easy deployment, but also for easy maintenance. Obviously, a blimplike object floating at 1,000 feet (305 meters) could receive quite a beating from the elements, but the company estimates the MARS should last at least 15 years before requiring maintenance. To achieve this longevity, the inflatable part of the turbine is made from an extremely durable fabric used by most current airships. The woven outer part is actually made from the same material used in bulletproof vests and is lined with a coating that protects it from UV rays and abrasion. The inner portion is coated with Mylar (the silver part you see in helium balloons) to prevent the helium gas from escaping.
Since the MARS is located at such high altitudes, it was also designed to be able to withstand strong winds. While conventional turbines will shut down at wind speeds in excess of 45 mph, the MARS can function at speeds greater than 63 mph. At the other end of the spectrum, the MARS turbine can also convert wind energy into electricity at wind speeds as low as 7 mph [source: Magenn].
Part of what enables the MARS to stay vertical at high wind speeds is due to something called the Magnus effect. This refers to the lift created when a curved object spins while moving in a fluid medium like air. When the object spins, an area of high pressure forms beneath it and causes it to rise. Golf balls, when hit a certain way, and curveball pitches in baseball, have a back spin that causes them to lift in flight -- this is the Magnus effect. Since the effect increases as wind speed increases, the MARS is able to use it in combination with the lift from the helium to maintain a near vertical position and not lean in high winds.
The wide range of speeds at which it can operate means that the MARS can deliver output much closer to its rated capacity than standard designs can. This is because although wind energy can theoretically generate significant amounts of electricity, most generators only produce a fraction of that because of inconsistent winds.
The design of the MARS turbine didn't just appear to its creator overnight, though. It's actually been around for quite a while. Find out where MARS came from -- and where it's going -- on the next page.
Past, Present and Future of MARS
Interestingly, the basic idea behind the MARS turbine has been around since the late 1970s. Fred Ferguson, the company founder, actually initiated it when he invented the Magnus Airship. Patented in the 1980s, the airship was a large, round, helium-filled sphere that rotated backwards as the airship flew forward, producing lift (the Magnus effect). The faster the craft flew and the faster the wind speeds, the higher it would go.
More than 30 years later, Ferguson realized that the airship concept was also a potential source of renewable power. Converting the spinning motion of the blimp into electricity would be a great way to harness the higher-speed winds accessible to the aircraft. After years of research and millions of dollars worth of funding, the MARS turbine is nearing its final stages of testing and should be ready by 2010.
The first MARS turbine will be a 10 to 25 kW model capable of producing 10 kW. Magenn will then work on a 100kW size. If both of those are successful, Magenn hopes to eventually return to its plans to develop a smaller 4 kW backpack model for use by campers or homeowners. The turbine is expected to cost between $5 and $10 per watt, so that a 10 kW model would cost between $50,000 and $100,000; the operating cost of the power should be around 15 cents per kWh [source: Magenn].
Although these costs are higher than the average of 5 cents/kWh of conventional wind energy, they could potentially drop down quickly. For comparison purposes, conventional wind energy cost up to 30 cents/kWh when it first came out more than 30 years ago, but the price dropped as the technology improved and became more widespread. Likewise, the cost of energy generated by MARS could follow a similar trend.
Regardless of the cost, being able to set up wind turbines with the simple infusion of helium gas and a sturdy tether certainly opens up possibilities. For more on wind-energy turbines and the future of wind power, test out some of the links on the following page.
Related HowStuffWorks Articles
More Great Links
- Alter, Lloyd. "Magenn Air Rotor System Finally Floats." Treehugger.com. May 5, 2008. (July 7, 2008).http://www.treehugger.com/files/2008/05/magenn-air-rotor-floats.php
- American Wind Energy Association. "awea.org." 2008. (July 7, 2008).http://www.awea.org/
- Dorn, Jonathan G. "World wind power reaches 100,000 megawatts." Peopleandplanet.net. March 4, 2008. (July 7, 2008).http://www.peopleandplanet.net/doc.php?id=3219
- Hamilton, Tyler. "A Balloon in the Wind (Market)." Greentechmedia. April 16, 2008. (July 7, 2008).http://www.greentechmedia.com/articles/a-balloon-in-the-wind-market-787.html
- Layton, Julia. "How Wind Power Works." HowStuffWorks. 2008. (July 3, 2008).https://science.howstuffworks.com/wind-power.htm
- Magenn. "Magenn Power Air Rotor System." (July 3, 2008).http://www.magenn.com/#
- Williams, Wendy. "When Blade Meets Bat." Feb. 2, 2004. (July 3, 2008).http://www.sciam.com/article.cfm?id=when-blade-meets-bat