It was spring, and I was with my best friend Katelyn. We were a month away from graduating Kindergarten and knew nothing could stop us. Not even the lack of wind threatening to bring down our plastic kites. This is the image my mind conjures when the word “kite” is uttered. Not surprisingly, most Americans think of kites as the childhood pastime, rather than the future of renewable energy. After viewing Saul Griffith’s TED Talk, “High-altitude wind energy from kites,” however, my conventional association of kites with toys was challenged.
In 1980, amid the nation’s oil crisis, an engineer named Miles Lloyd published a paper on the significant potential of crosswind kite power. This paper, although largely ignored by the scientific community, was extremely progressive in its notions and theories. The ideas were so progressive, in fact, that society at that time was incapable of properly rendering these crosswind kites due to lack of technology. Within the past ten years, however, the advancement of technology, specifically the improvement of materials, sensors, and computers, has enabled engineers to rethink the potential of wind power. Saul Griffith, an eccentric and intelligent inventor, became particularly enchanted by the thought of a new method of retrieving alternative wind energy.
Griffith is the president and chief scientist of Makani Power, a company that creates airborne wind turbines (AWT), or energy generating kites. These AWTs operate on similar aerodynamic principles as conventional wind turbines, but reap a multitude of greater benefits. The rotors of the AWT can be used as propellers and turbines, therefore, during its launch, the rotors lift the kite into the air. With no fuel or batteries, the wing has a very high thrust to weight ratio. Energy is cultivated through the small turbines driving high-speed direct drive generators. This electricity is then transmitted through the AWT’s kite tether, which is harnessed to the ground; wind is harnessed into energy by pulling against this tether. The energy is then conveyed into the “grid” housing all of the renewable energy. This kite is guided in a circular path, similar to the path of a conventional turbine, at 1,000 feet by on-board avionics computers. Thus, an alternative form of energy is harvested.
In comparison with conventional wind turbines, AWTs provide a large number of advantages. Principally, this alternative form of wind energy is approximately 50% less expensive. In conjunction with this benefit, AWTs are 10% of the mass of a conventional wind turbine. Consequently, this significant difference in size reduces manufacture, transportation and installation costs, as well as reduces the infrastructure necessary for on-site maintenance. Moreover, with this technology, approximately four times the amount of energy produced by conventional wind turbines is available. This is primarily a result of AWTs’ capability to cultivate energy from offshore resources; AWTs can reach wind power above the ocean.
Wind over the seas, a basically untapped source of energy, is stronger and more abundant. Also, about half of the nation’s citizens are within a short distance of a shore. Thus, energy can be utilized on site, and will not have to be transported across the nation. On another imperative note, energy providing kites pose a very low threat to the environment, even reducing the environmental effect of conventional turbines. An explanation for this claim is because of the flying style of the AWT and the design; the AWT flies above the path of most birds, and the design is less prone to nesting and perching. The most important aspect of AWTs, however, is that is extremely high-performing, boasting 50% more energy cultivation that conventional turbines. AWTs are able to access stronger and more consistent winds at a higher altitude.
If AWTs are smaller and can produce a cheaper, more efficient, and less environmentally harmful source of energy, then why haven’t we heard of wind kites? Moreover, why aren't all of our renewable energy sources being transformed into AWTs? The answer, quite simply, may be that the nation just doesn't have the money or time to replace alternative energy producers that already work. Even non-sustainable energy sources, such as coal, are hard to compete with economically. When desire for a sustainable earth is more overwhelming than desire to save money, crosswind kites will appear predominantly in society. While it may take several years, these wind power kites should be the future of renewable energy. The toys we all once played with as children may soon be the “toys” that the next generation depends on for living.