Flywheels are often referred to as the modern sources of clean power, and the need of the hour. These wheels not only allow for cost-efficient means of storing energy, but also have a number of uses in today’s technological world. From satellites and NASA, to hybrid cars and UPS’s – many technological needs of today are met by the flywheel technology, using simpler materials than before, and expected to show huge savings in the long run.
A flywheel is a cost-efficient method of storing energy. It is a heavy rotating disk that is used as a storage device for kinetic energy. Flywheels are special in that they resist changes in their rotational speed. This helps to steady the rotation of the shaft at the time that an uneven torque is exerted on it by a power source, such as a piston-based engine. The fact that flywheels resist changes in their rotational speed further helps to steady the rotation of the shaft when the load that is placed on it is uneven (“Flywheel”).
Flywheels are used to produce high power impulses for experiments in which the drawing of power from the public network would be unacceptable in that it would produce unacceptable spikes. A small motor is typically used to accelerate the flywheel in between impulses (“Flywheel”). This technology has many other uses, no doubt. Moreover, flywheels are simpler than the traditional stores of energy, and cheaper in the long run.
Today, there is talk of using flywheels as power storage devices for vehicles to boot. Flywheels are also common in low-cost toys. Additionally, a momentum wheel, which is a kind of a flywheel, is being used in satellite pointing operations. In these, flywheels are used to point the satellite’s instruments in the correct directions without the need for thrusters (“Flywheel”).
Flywheel technology may very well turn out to be the next major source of clean power (Teschler). Even NASA is contemplating its use for the International Space Station – in a search for a way to hold the electrical energy that is generated by the station’s solar panels, in darkness, without having to suffer the fickleness of chemical batteries (Schneider). In this case, flywheel technology would be made to rely on field oriented control techniques that were borrowed from AC motor drives to ensure high torque and efficiency in giving power to the flywheel (Teschler).
Today’s flywheel designs are stronger despite the fact that they use comparative light composite materials. These flywheels can be spun at high speeds without falling apart. According to American Scientist, “This approach is advantageous because the amount of energy stored in a flywheel scales linearly with mass but increases with the square of the rotational speed” (Schneider).
Engineers at the University of Texas at Austin are also employing the flywheel technology in the Advanced Locomotive Propulsion System. This system uses a flywheel instead of a chemical battery. Furthermore, the flywheel used with this system is perhaps the largest high-speed flywheel in the world in terms of its energy storage capacity – 133 kilowatt-hours at a
maximum design speed of 15,000 rotations per minute. It is also the most cost-efficient flywheel technology in place, on a cost per mega-joule basis (Schneider).
At the Austin data center of Freescale Semiconductor Inc., a UPS system was recently installed, making use of flywheel technology. This CleanSource flywheel built by Active Power Inc. is known to cost 50% more to install than a comparably sized battery UPS. However, it runs more efficiently than the traditional technology, and takes up about one-third less floor space. Moreover, this flywheel technology does not need its batteries replaced, thereby making it easier to maintain, and raising its uptime. According to experts, this new technology is definitely going to show at least 40% savings in the long run – approximately ten years (Mitchell).
While engineers spend time and money to analyze the cost efficiency of flywheel technology, apart from its uses, there is a fact of certainty: flywheel technology is here to stay, and especially so because of the environmental concerns of modern living. Flywheels are, after all, clean power sources.
“Flywheel.” Wikipedia (2007). Retrieved from http://en.wikipedia.org/wiki/Flywheel. (10 February 2007).
Mitchell, Robert. “Flywheel technology puts new spin on power: Some data centers are adopting UPSs that use flywheels instead of batteries as the power source. Here’s why.” Computerworld (2 October 2006). Retrieved from ttp://www.computerworld.com/news/index.jsp. (10 February 2007).
Schneider, David. “Getting All Revved Up: Large energy-storage flywheels are being tested for some surprising applications.” American Scientist (Jan-Feb 2007).
Teschler, Leland. “New Spin for Flywheel Technology: After years of being billed as the next great revolutionary means of propulsion, flywheels may finally be ready for prime time.” Machine Design (16 September 2004). Retrieved from http://www.machinedesign.com/ASP/strArticleID/57259/strSite/MDSite/viewSelectedArticle.asp. (10 February 2007).