Advanced Invention

Who knew that providing energy and water for all could be a matter of foot cranks and dirt power?

A garden hose, a tin can, duct tape, metal piping, kitchen cleaner, and gasoline: That is all television icon MacGyver needed to make a flame-thrower to ward off a swarm of killer ants. In the real world, technologies that are affordable and practical are not so simple to create, but they can make a huge impact on people’s lives. Instead of calling on complex solutions (reliant on engines and imported resources) for low-tech problems (such as cooking and lighting), some researchers are now developing what they call "confluent" technologies—ones that are effective, affordable, and sustainable for use in the developing world. Here’s a look at the latest breakthroughs:

1  Energy in a Bucket of Dirt
Who needs nickel cadmium batteries or coal plants for electricity when you have soil? A Harvard team of faculty and African students have tapped into soil-dwelling microbes in order to provide electricity for families in Tanzania. When the microbes found in the soil digest organic materials, they naturally produce a small current, which can be harnessed with a simple device consisting of two electrodes and a small circuit board. One trash-barrel-sized unit filled with soil can produce enough electricity to light two bedrooms for a decade or more, says Harvard biology professor Peter Girguis. While each unit currently costs about $50, the team is testing new materials that would drive the price down to $7.

2  Micro-Hydroelectric Power
Hilly land streaked with small streams makes an ideal spot for micro-hydroelectric power generators, each of which requires a meager water flow of just three gallons per second to turn. (To put this in perspective, the Mississippi’s average flow at New Orleans is about 4.4 million gallons per second.) The Appropriate Infrastructure Development Group (AIDG) has helped to build three systems in Guatemala, and more communities are now saving up money for local installations.

TOKYO (AFP) - Japanese researchers say they have developed a rubber that is able to conduct electricity well, paving the way for robots with stretchable “e-skin” that can feel heat and pressure like humans.

The material is the first in the world to solve the problems faced by metals — which are conductive but do not stretch — and rubber, which hardly transmits electricity, according to the team at the University of Tokyo.

The new technology is flexible like ordinary rubber but boasts conductivity some 570 times as high as commercially available rubbers filled with carbon particles, said the team led by Takao Someya at the university’s School of Engineering.

US automaker General Motors said Tuesday it will equip the roof of its factory in Zaragoza in northeastern Spain with solar panels to create the world’s largest rooftop source of power from the sun.

A solar thermal electric power plant in Sanlucar La Mayor, Spain in mid February. US automobile giant General Motors is set to announce that it will build the world’s largest rooftop solar power station at its biggest factory in Europe.

Plans are afoot to reuse spent reactor fuel in the U.S. But the advantages of the scheme pale in comparison with its dangers

• Spent nuclear fuel contains plutonium, which can be extracted and used in new fuel.
• To reduce the amount of long-lived radioactive waste, the U.S. Department of Energy has proposed reprocessing spent fuel in this way and then “burning” the plutonium in special reactors.
• But reprocessing is very expensive. Also, spent fuel emits lethal radiation, whereas separated plutonium can be handled easily. So reprocessing invites the possibility that terrorists might steal plutonium and construct an atom bomb.
• The author argues against reprocessing and for storing the waste in casks until an underground repository is ready.

A new energy concept called a solar tower could generate enough electricity for 200,000 homes. Looking like a giant smokestack, it would release no noxious fumes — just sun-heated air.

Demonstrated more than 20 years ago, the basic design calls for solar collectors to warm the air near Earth’s surface and then channel it up the tall central tower. Turbines placed at the bottom make electricity from the updraft.

“It’s a combination chimney, windmill, greenhouse,” said Kim Forté of EnviroMission Limited in South Melbourne, Australia.

EnviroMission has designed a kilometer-high solar tower (0.62 miles) and is now looking at possible sites in the southwestern United States.

Solar-stack
The solar tower is an updated version of a solar chimney — a centuries-old technique for providing ventilation to a home by creating a natural updraft from sun-heated air.