Magenn floating wind generators take advantage of high altitude winds
By Loz Blain
February 26, 2009
February 27, 2009 Wind power is notoriously flighty, particularly at ground level. Most turbine-on-a-post wind powered generators operate at around 20-40% of their rated generation capacity, simply because wind is intermittent and changes direction. But a generator situated 500-1000 feet above ground level would enjoy much more consistent strong wind - which is why the Magenn MARS system makes so much sense. It's a helium-filled rotating airship that spins in the wind on the end of a variable-length tether that also acts as a power transmitter, and it's expected to operate at more like 50% of its rated capacity. Each MARS system will be cheap and portable, which will make them extremely useful in rural, camping and emergency situations. A prototype has successfully been flown in North Carolina. A great idea that makes economic sense.
Anatomy of MARS
Each MARS unit (Magenn Air Rotor System) effectively comprises a helium-filled blimp, tethered at each end with rotating generators. The body of the blimp has fans attached to it to catch wind and generate spin - and once the unit is spinning, it generates extra lift due to the same "Magnus Effect" forces that cause spinning baseballs and golf balls to curve in the air.
Once it's airborne and spinning, it generates power which is transmitted to a station on the ground via the insulated tether cords. It doesn't matter if wind direction changes, there's a sort of disc rudder in the middle of the MARS unit that consistently points it perfectly into the wind wherever it comes from. Wind doesn't have to be strong to get it turning; as little as 1 meter/second is enough to start generating, and the system will operate in higher wind speeds than conventional generators as well - although Magenn recommends pulling it down in extreme weather.
Location, Location, Location
The MARS system is designed to take advantage of the much more consistent wind levels available at higher elevations than standard wind generators can generally reach. Putting wind generators hundreds of feet above ground also means that they don't have to be situated in high-cost prime coastal locations, where they have generated a lot of 'NIMBY' resistance and aesthetic criticism. MARS units will be just as effective inland, closer to the main power infrastructure and usage sites.
Capacities and Economics of the MARS System
The system's expected capacities aren't huge - the 30x57 foot MARS Alpha prototype generated 2kW of power, although this will be increased to 10 or 12 kW in time. A 100kW model for remote industrial sites is in the works, and inventor Fred Ferguson has flagged the potential for a backpack-sized version suitable for camping and emergency situations that won't even require helium, generating enough lift just from the Magnus Effect to stay airborne as it generates. Remarkable!
As with any energy generation device, the key question is: will the MARS system produce cheap enough power to be viable? The answer appears to be yes. Magenn expects home-sized 4kW units to cost around USD$10,000, camping/boating sized 1kW units around USD$2000, and, due to the fact that they will operate at a much greater percentage of their rated capacity, the overall cost of electricity generation will be significantly less than with standard turbines, particularly once the larger 100kW, 800kW and 1.6MW versions are operational.
Naturally, the tethered MARS systems will cause a few headaches for pilots - and Magenn is looking into ways to arrange for suitable permits and mini no-fly zones to be arranged. And while the spinning blimps appear to be vulnerable to anyone with a rifle, the Kevlar-like Dacron material they're built from should be enough to protect them from most attacks.
The project has been in development for several years now, and with the help of new investment could begin making a commercial push. We wish Fred and the Magenn team the best of luck in the initiative.
For more information, see the Magenn Power website.