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.

Thursday, August 21, 2008

Brighter World

Brighter World premieres right after Raining Forests at 10pm August 29th on the Discovery Channel.

Brighter World plays on the fact that bright white water vapor clouds reflect sunlight back into space better than oceans or land, thus resulting the effect of global warming. This phenomenon is called global dimming and many scientists and professors have noticed this effect before.

In this episode, the Project Earth team tries to expand on the idea of creating man-made clouds in order to prevent the Earth absorbing excess sunlight causing global temperatures to rise. The team hopes that the clouds that are produced will help reduce the temperatures on Earth since less sunlight is being absorbed by the ground.

Updates from the show: The idea for this Project Earth episode is to geoengineer regular clouds. The plan is to use sea water to redistribute the molecules of water in clouds to redirect more sunlight back into space.

Regular clouds only reflect about 50% of sunlight back into space. The team expects that if very small salt particles are used inside the water droplets of clouds, this will reflect another 10% of sunlight back into space. Ten percent may seem like a very small amount however the amount of particles needed will need to be 4 times as many in a square inch.

The team would like to create Marine stratoculumus clouds. These clouds form between 200 and 400 feet above water. These clouds are ideal since marine stratoculumus clouds do not produce rain clouds since they are so low to the ground.

The Project Earth team ran into a problem though. They could not generate small enough particles using their proposed water jet theroy. The water particles averaged 14 microns across. Their goal was to create particles about 1 micron.

The team then moved onto another idea. They tested salt flares to see how small the particles were. They found out that the particles were less than 1 micron across making them ideal to test a geoengineered cloud.

The project used 300 flares set off simultaneously off the back of a boat. After some time, the particles were carried up in thermals into the condensing layer. This created a cloud exactly where they were hoping.

The cloud was about 100 feet wide by about four miles long. The cloud's volume was about six million square meters. They estimated that this cloud could potentially off set the carbon produced by about four or five power generating stations.

Project Earth - Raining Forests

In the Raining Forests episode, the project earth team focuses on replanting vast forests with saplings. Instead of the normal traditional means with hands and shovels, the team plans to plant entire forests high above the ground in a helicopter. Being high above has its advantages, it is easier to disperse the fauna over a larger area in less time.

As forests are replanted, they absorb large quantities of carbon dioxide as the newly planted trees grow.

The Raining Forests episode of Project Earth premieres on August 29th at 9:00 pm EST on the Discovery Channel.

Update from the show: The Project Earth team tackles deforestation in Raining Rainforests. Current estimates say a forest the size of West Virginia is lost every year. In order to keep up with this trend, a forest twice the size of Manhattan must be replanted every day to be effective.

The team plans to test their replanting theory in the Mississippi delta. Recent hurricanes, Katrina and Rita, destroyed over 320 million trees by blowing them down or poisoning them with salt water.

Since Mangrove trees are native to the Mississippi delta, the Project Earth team will attempt to repopulate an island with Mangrove propagules.

Mangrove forests have decresed by 20% all over the world since the eighties, faster than rain forests. Mangroves are the most cost effective since they absorb a very large amount of carbon dioxide. Although, this design can be changed to accomodate any tree for any ecosystem.

The Project Earth team plans to drop propagules out from a plane. They estimate that a 4 foot spread pattern is needed if the propagules are to have optimum forest growing conditions.

It turned out that an airplane was too dangerous since the spread pattern was not optimal since the plane had to travel very slowly. The risk of the airplane stalling was too great so the team had to settle on using helicopters.

After a few tests to see how they would drop the propagules from the helicopters, the team decided to use large nets hanging below the helicopters. After the propagules were dropped from the helicopters, the project earth team would reconvene a the site three months later to see if any of the trees were still alive.

Even with all the effort and planning, the propagules were unable to take root after three months. The project earth team decided that their current ideas on this project will need some fine tuning since nothing was able to take root.

Wednesday, August 20, 2008

Project Earth - Wrapping Greenland

Project Earth, episode two Wrapping Greenland, the premise of the second episode is to see if wrapping glaciers in geotextile blankets.

The project earth team tests their theory on a glacier located in Greenland. The team believes that if glaciers are wrapped in blankets, the blankets will insulate the ice from melting.

The blankets using special synthetic geotextile materials are expected to help reflect the sun's rays during the summer melting season.

Although the idea is pretty good, the costs sound unreasonable. The costs for these materials will average about 12 million dollars per square mile. How valuable is fresh water to you? How valuable will fresh water be in 50 years?

Wrapping Greenland will premiere on the Discovery Channel on August 22nd, at 10:00 pm EST, immediately following Engineering the Future.

Updates from the show Wrapping Greenland: The Project Earth team decided on instead of wrapping the entire island of Greenland, they focused on local melting points. The team compared the melt with a bowl of ice cream. The ice cream stays frozen in the center; however, the sides are the places where it melts. The team will focus on only covering two acres around a melt lake near the edge of Greenland's ice line.

Materials that were included are the same white tarps used in the alps on Austrian glaciers and bamboo. Metal was tested to hold the sheets down but the metal conducted heat. Plastic was also considered however it was proven to be too brittle. Bamboo is renewable resource and it is very environmentally friendly.

The results of the test actually proved to be much better than expected. The two acres of material saved and compressed ice by two feet. The material saved 5000 tons of ice from melting.

If this test was ramped up to full scale where it covered all of Greenland it would cost $400 billion for 771 million blankets. In order to move all of these tarps, the team would need 31 million helicopter transports costing $186 billion. On top of the $586 billion dollars on just materials and transportation, the wages of the people working on these tarps is not even factored in. Aside from costs, covering glaciers in a large scale will in fact out weigh its carbon footprint.

Even though it seems that it works; currently, it is only feasible for small scale deployments. Covering glaciers with blankets should only be considered for glaciers used for drinking water.

Covering glaciers with tarps seems only to tackle the effects of global warming, perhaps we should focus more on the cause.

Project Earth - Engineering the Future

The episode Engineering the Future debuts the mini-series on Friday, August 22nd at 9pm EST.

Engineering the Future, the first of the episodes, sounds to be the plot basis of the entire Project Earth mini-series. The team of scientists and engineers discuss their experiments to save the planet. This episode should lay the ground work for every other episode after this one.

Aside from the synopsis of the episode on the discovery website nothing else has been released regarding the first program.

Discovery Project Earth

The episode list for Discovery Channel's Project Earth is as follows. Each listing is for the episode's debut, each show will be replayed during the week of its airing.

Engineering the Future - Aug 22, 9:00 pm
Wrapping Greenland - Aug 22, 10:00 pm
Raining Forests - Aug 29, 9:00 pm
Brighter World - Aug 29, 10:00 pm
Infinite Winds - Sep 05, 9:00 pm
Hungry Ocean - Sep 05, 10:00 pm
Space Sunshield - Sep 12, 9:00 pm
Orbital Power Plant - Sep 12, 10:00 pm
Fixing Carbon - Sep 19, 9:00 pm

Some of these ideas sound a bit far fetched but lets see what Project Earth can do.