MARS: Taking Wind Power to a Higher Level

At the most basic level, generating electricity from the movement of wind is straightforward. 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.

The MARS turbine can reach the higher speed winds available 1,000 feet (305 meters) above ground level.

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.

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.

The MARS turbine, on the other hand, avoids all that. It's simply kept aloft by a lighter-than-air gas like helium.

The MARS envelope will be made of a durable material like that used in bulletproof vests.

II Inside MARS

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.

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 - 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.

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.

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.

Date: 2015-02-16; view: 942