Tuesday, July 31, 2007

Solar and wind power in the sky

Solar panels and wind turbines only work when there is sufficient sunshine or wind. There are ways to overcome this disadvantage, such as storing the surplus electricity generated on sunny and windy days by pumping up water from a lower to a higher lake, to regain this energy as hydro-electricity later. 

Alternatively, car batteries could be charged when there is abundant electricity, to sell power back to the grid at better prices when there is high demand.

Another approach is to seek and harvest solar or wind power at locations where there is more permanent wind or sunshine. Wind turbines could be located in the sky. Bryan Roberts, professor of engineering at the University of Technology, Sydney, proposes clusters of wind turbines flying 15,000 feet high in the air. After studying the topic for 25 years, Roberts designed a helicopter-like rotorcraft to hoist a wind turbine high into the air, where winds are persistent and strong. Once there, the wind turbine is powered by its own electricity and keep itself in place, while transmitting electricity to the ground through a cable. Roberts has teamed up with San Diego-based Sky Windpower, which plans to produce a flying wind turbine with four rotors. The rotorcraft will go into the first layer of the atmosphere, called the troposphere. With GPS technology, the crafts can be kept in position to within a few feet.

Instead of using a cable to transport electricity down to the ground, electricity could also be tranferred through microwaves. Decades ago, Dr. Gerard K. O'Neill proposed to locate solar panels in space where solar power would be converted to low-density radio waves, sent to Earth and converted to electricity. O'Neill proposed this as part of a wider plan to colonize space. A publication by William Brown shows that the technology to transmit electricity by radio waves with a high degree of efficiency was already used as far back as in 1965.



Monday, July 2, 2007

Wow Energies a contender for Branson $US25 million award

As discussed, Richard Branson encourages companies to come up with solutions by offering a $US25 million award to anyone who can take existing carbon dioxide and other greenhouse gases out of the atmosphere. 

An earlier post mentioned Klaus Lackner, physicist at Columbia University, who proposes artificial trees to suck carbon out of the air. The trees suck in carbon dioxide for storage under the ocean-floor in disused oil or gas fields. 

Another contender for this award and working along similar lines is Wow Energy, a Texan company that builds equipment to clean the air from pollutants. They originally developed their technology to provide a cleaner process at the point of emission, e.g. when burning fossil fuel at a power plant ("clean coal"). 

Note that the Branson award is to clean ambient air from greenhouse gas emissions, as opposed to scrubbing done at power plants or through filters in cars, but if it works well for ambient air then that would be great. For more details, go to Wow Energies

Monday, June 4, 2007

Polar ejection of carbon dioxide

Dr. Alfred Wong of the University of California, Los Angeles, proposes to send carbon dioxide into outer space using lasers and radio waves at the arctic.

See A stairway to heaven? in The Economist


Tuesday, May 15, 2007

Electricity for Europe

Here are three ideas to supply Europe with electricity:

1. Geothermal power from Iceland

In April 2007, the Icelandic National Energy Authority signed a deal with Energie Baden-Wuerttemberg from Germany, to work on electricity being transmitted to Germany from Iceland. A 1,200-mile ocean-floor cable is envisaged to carry electricity to Britain’s national grid before reaching Germany. The proposal is to drill 3.8km through the Earth's crust into the hot basalt below, in order to tap into temperatures of up to 600C and generate enough geothermal electricity to power up to 1.5 million homes in Europe.

See Iceland’s hot rocks may be power source for UK in The Sunday Times


2. Hydropower from Congo

The Grand Inga power station is a project to harness hydropower of the Congo River. Located near the mouth of the Congo River, with an output of 39,000 megawatts, Grand Inga would be the world's biggest hydroelectric scheme, generating twice the power of China's Three Gorges dam.

Three electricity superhighways would deliver power south to Angola, Botswana and South Africa, west towards Nigeria and north to Egypt and - ultimately - southern Europe. The project might cost $US80billion, but power delivered from Grand Inga to the Italian border would cost less than the current market price of electricity in Italy today.

See Africa waits on scheme to harness the power of the Congo River in The Sunday Times


3. Thermal solar power from Africa

The Trans-Mediterranean Renewable Energy Cooperation (TREC) was founded in September 2003. One proposal is for Thermal Solar Power to be generated in the deserts of Africa, for transmission by means of High-Voltage Direct Current cables to Europe, with losses of only about 3% per 1000 km, adding up to losses across the Mediterranean of 10-15% to Europe.













The above picture below is from:
http://en.wikipedia.org/wiki/Image:Fullneed.jpg

The red squares on the image represent the theoretical space needed for solar power plants to generate sufficient electric power in order to meet the electricity demand of respectively the World, Europe (EU-25) and Germany, based on data from a study by the German Center of Aerospace (DLR), P. 12 bzw. 26, 2005.



Monday, May 14, 2007

Sun shields from Moon Dust

Curtis Struck of Iowa State University suggests that lunar dust particles are just the right size to scatter sunlight. They could be positioned in the Moon's orbit in a pair of stable clouds that would each pass in front of the Sun once a month, blocking sunlight for about 20 hours each month
(Journal of the British Interplanetary Society, vol 60, p 1).



Monday, May 7, 2007

Planktos - seeding the oceans with iron

Planktos plans to fertilize the oceans with iron to stimulate growth of phytoplankton, microscopic marine plants that soak up carbon dioxide. Their ship plans to dissolve tons of iron over a 10,000-square-km patch.

https://www.youtube.com/v/Qe1fOxQSUKs

For more details, see: Planktos.com The Independent NY Times


Cloud Seeding

Cloud seeding is proposed by John Latham and Stephen Salter, who suggest to spray droplets of seawater high up into the air, so that the tiny particles of salt from these droplets will make clouds thicker and more reflective. The project featured prominently in the BBC documentary: 
Five Ways To Save The World

There's also a video: 
https://www.youtube.com/v/fg7J8P-uXqM

Stephen Salter proposes to make rain with floating wind turbines that make very choppy waves, known as Faraday waves. A high-frequency ultrasonic generator would spin seawater around inside a grooved drum, producing tiny waves that are thinner than a human hair, throwing tiny droplets of water from their crests up into the air. As this fine mist of sea-spray evaporates, tiny particles of sea-salt remain in the air and get sucked up into the air, especially when the sunshine causes rising currents of air. These little salt particles act as centres attracting extra droplets to form darker clouds further up in marine stratocumulus clouds. Stephen envisages a multitude of ships to criss-cross the oceans, remotely controlled with their position tracked through GPS and their destination determined by weather patterns. This idea of making rain in this way could also be combined with another idea discussed earlier in this group, i.e. of exploiting temperature differences in the sea. http://groups.google.com/group/greenhouseeffect/msg/4a21d06ae5b08c04

The deeper you go down into the ocean, the colder it gets. At the lowest points, the temperature is near freezing point. Ships could drag a pipe along, reaching down a few hundred metres into the ocean. Through this pipe, cold water could be pumped up by a solar-powered pump to be released back into the sea from a little tower of, say, two metres high. As the cold water falls down into the sea, the evaporation will act as an air-conditioner. Furthermore, condensation around the top of the pipe will drip down and can be captured in containers, to be sold as fresh water. So, apart from harvesting clean, potable water in the above way, such a ship could also be anchored at a location where it could throw part of the seawater up into the air in the way Stephen Salter proposed, as a fine mist, in order to produce more rain in the proximity of a dry area on land. 

Sam Carana 
- March 3 2006


Sulphur into the stratosphere

Some are considering releasing dust particles in the air to reflect some of the sunlight, as an alternative to positioning mirrors in orbit above Earth. [There are] a few problems with the dust-particles approach, such as difficulties in regulating the right amount of dust. It may turn out that - in hindsight - too many dust-particles have been released in the atmosphere and that it will be quite a problem getting them out again. Another problem is that the dust-particles method will affect the climate everywhere on Earth.

Sam Carana 
- May 20 2005 

One such proposal is by Paul Crutzen, who won the Nobel Prize for chemistry when he discovered the causes of the hole in the ozone layer. Paul proposes to shoot hundreds of rockets loaded with tons of sulphur into the stratosphere to create a vast, but very thin sunscreen of sulphur around the earth. 

The proposal was discussed in the BBC documentary: 


Artificial Trees

Klaus Lackner, physicist at Columbia University, has proposed artificial trees to suck carbon out of the air. The trees suck in carbon dioxide for storage under the ocean-floor in disused oil or gas fields.

Such trees could be planted anywhere. A small one could sit like a TV on the lawn to balance out the CO2 emitted by one person or family. A large tree, the size of a barn, could sit in the open air, near repositories for easy transportation and storage of carbon. Klaus Lackner estimates that some 250,000 such trees worldwide would be needed to soak up the CO2 produced by human activity annually.
BBC News, 21 February 2003 
Amazon.com News

More recently, Klaus Lackner's trees featured prominently in the BBC documentary
Five Ways To Save The World


Mirrors in Space

The concept Mirrors in Space was discussed in an article from the summer 2001 Whole Earth Review, Mirrors & Smoke: Ameliorating Climate Change with Giant Solar Sails, by Kenneth I. Roy, PE and Robert Kennedy, PE.

Over the years, the concept has been discussed in many posts, including in the geo-engineering group by Sam Carana

The ABC show, Good Morning America, on January 29, 2007, featured a clip on mirrors in space, featuring a proposal by Roger Angel, University of Arizona, to send many small discs into space to form giant mirrors deflecting some of the sunlight from Earth.



Roger Angel's research into the feasibility of cooling the Earth with a cloud of small spacecraft near the inner Lagrange point (L1) has been discussed at:
National Academy of Sciences
National Institues of Health

Sciencenews.org
Roland Piquepaille