Wednesday, August 27, 2008

Infinite Winds

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.


Anonymous said...

This episode is wrought with bad engineering from the start. First, the instability they encountered with their scale models was due to the fact that they have built a gyroscope, and that the torque vector of that rotating system is oriented orthogonal to it's plane of rotation; thus the side to side sway. Their turbine was exerting a sideways force for which they did not account, and about which they were surprised (this, of course, is undergraduate level physics).

Secondly, their scale model did not account for the difference in moment of inertia between the small turbine and the large turbine. Even Bill Nye the Science Guy knows that "inertia is a property of matter," and heavier things have much more of it that light things. The difference is why the big turbine doesn't rotate at the low wind speeds--not to mention the drag created by the large balloon surface area.

Supposedly they have an engineer on staff. Sounds like their engineer needs to go back to school to avoid embarrassing themselves.

Anonymous said...

I first like say I love the concept of using balloons to harness energy from the wind. I do have a couple of possible ideas that might be worth looking into.

First one is why not use Hydrogen instead of Helium? Yes yes I know the Hindenburg. But think about it. These balloons are much smaller and if they do burst into flames for some reason, which is probably not likely to happen, they are going to be 300 feet up in the air minimum where the explosion will not harm anyone. An explosion will overall have the same effect as a helium balloon failing and crashing down to earth. I would suggest an emergency parachute be deployed upon catastrophic failure of any balloon.

What are the benefits of using hydrogen? One it is lighter so therefore the balloons can be smaller or carry a larger payload. Secondly and probably most important is that by using a small amount of electricity generated by the balloon itself you could created a system that replenishes the balloons own hydrogen supply. A small water collection container could be mounted on the cable near the bottom of the balloon. Using this collected water you pass a current of electricity generated by the balloon’s own wind generators to separate hydrogen from oxygen. The balloon thus becomes self sustaining.

My second suggestion is why have the balloon doing two jobs? My suggestion is have a balloon lift a Darrieus turbine or a number of smaller Darrieus turbines. With Darrieus turbines you don’t have to worry about orientating it to the wind direction.

Also you could attach a series of balloons and Darrieus turbines in a daisy chain. Each balloon lifting its share of generators and cable. Connect multiple daisy chains horizontally and you could have a floating wall of wind generators.

Lastly why not take advantage of the temperature difference between night and day to generate electricity? As the day warms hydrogen expands creating more lift. This increase in pull on the balloons cable could be use to turn an electric generator on the ground by slowly letting more cable out. Then as the night cools the hydrogen contracts and the balloons will start to lose altitude. Reel the cable back in and you’re all set for the next day.

tpriddy said...

The 1 versus 3 "stabilizing" vanes test stopped the spinning of the turbine by modifying the configuration of the tether. In essence they changed from one tether to two.

That's why the spinning was replaced by swaying.


TW process said...

How does one get in touch with the producers of this program to have them look at what we feel is a breakthrough new technology that can generate extreme amounts of electricity from medium force winds?

sriharsha said...

Can anyone tell the contact details of the Infinite winds team or the critics so that I need some clarifications to project a similar idea regarding a Vacuum based Power Generation Prototype System which can also be used anywhere in the world.

Anonymous said...

I don't know a whole lot about this type of thing...but how does one take in the environmental changes that happen on a daily basis. I mean if this thing is hooked into a power station or grid, what effect would lightning have on infrastructure?


Hello Sir, I had seen the complete episode of the infinite winds on tv. I am very much impressed by the effort given, and even, i would like to perform research on my concept of generating energy from infinte winds.I am an engineering student and would love to develop this product but lack proper resources and guidance. Can you provide me your invaluable guidance for its R&D for the sake of science and mother earth. Thanks.

Anonymous said...

this page is a big help! I'm doing a paper on this