The fifth episode of Discovery's Project Earth, airing September 5th at 9pm EST, is called Infinite Winds. Infinite Winds is based on the idea that winds on the surface of the Earth are slowed down by obstacles on the ground. This makes it less ideal for wind turbines on the ground. If wind power generators are somehow placed in high altitudes, they will produce more power since wind speed is greater.
The Project Earth team demonstrates this idea by floating wind power generators high above the ground. I'm not quite sure exactly how they will be accomplishing this idea, but I can take a couple of guesses.
Perhaps the team will some sort of a blimp or balloon to get a long cord with numerous wind turbines spread across the cord. If this cord is anchored to the ground, this will allow the wind turbines to transfer their power to the power grid.
Or, maybe the Project Earth team will create a ladder mill wind power generator. A ladder mill is comprised of a looped cord with wings spaced out across it. The wings going up provide lift which lifts the cord up and the wings going down provide drag pulling the cord down. This cord can help spin turbines on the ground to produce electricity.
There are a few ideas going around, let's see their plan in action.
Update from the show:
According to the Project Earth team, their plan is to engineer a new type of wind turbine that can be deployed high above the ground where surface obstacles do not interfere with wind currents.
After several tests, the team determined if they can send a large balloon filled with helium, more precisely a "rotating airship," and have it spin on its horizontal axis, they will be able to produce power. This is due to constant strong upper level winds. Their target for the placement of the rotating airship is between 300 and 1,000 feet above the ground. If they don't send the airship high enough, surface winds produce turbulence since many obstacles on the ground can change the direction of the wind.
The team would like to test their Infinite Winds theory with a one ton rotating airship 300 feet in the air tethered to the ground where the energy produced by its generators will be fed into the power grid.
Before they can try their large scale test, the Project Earth team tests several models in a GM wind tunnel.
Initial tests show that their first model would not work too well. The first model had no stabilization rudder and because of this, the model not only spun on its horizontal axis, it also spun on its vertical axis. This made the model spin uncontrollably.
The next model used three rudders, one in the middle and two at each end. This, like the first model, was not designed well. It spun uncontrollably as well.
The third and final model finally passed the wind tunnel test. The final model used a single rudder in the center. The single rudder helped keep air pressure high near the center of the turbine and allowed it to spin with precision.
The tether for the rotating airship is made with strands of copper wrapped inside vectran fibers. Vectran fibers are plastic based fibers that are very light and are super strong. Nine-tenths of an inch in diameter of vectran fibers can hold over six tons of weight.
As the team began producing their final test, they realized that the model could be further refined. Instead of straight edges the final model used chevron shaped blades. Using this design the chevron shaped blades will put further pressure on the central rudder stabilizing the turbine further.
Although with the many flaws, the design was considered successful. The model produced 200 watts of electricity.
After the success, the team considered what if this idea was perfect and it caught on with society. If they made 1.1 million aerial turbines at 1.5 mega watts each, it would be able to replace over 1,000 coal power plants. If they made even more, 9.5 million more, it would replace 15,000 coal power plants and save up to 85% of current carbon emissions.
The logistics and refining the technology are the major drawbacks. In order to make 9.5 million airships, 430,000,000,000 cubic meters of helium are necessary which is twenty-five times more than the current rate of production. If they can overcome these obsticles, they may have a way to harness wind energy.
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