"Personal power: solar utility in a backpack "

 

A solar power unit that can be carried in a backpack was created by a Portland, Oregon, inventor and is already making its way around the world.

 

"The Solar Power Pack contains a folding monocrystalline solar panel, battery, controller, plugs, cords and light. It weighs only 24 pounds but provides users with 120 watt-hours of power a day.

 

"The unit can power AC and DC electronics up to 300 watts. It can be used in recreational vehicles as well as for field research, emergency home power, disaster relief and international aid. (And, for those without enough cosmetic accessories, it can power a hairdryer.)

 

"After charging for six hours with the unit's solar photovoltaic panel, the Solar Power Pack can run a laptop computer for three hours or its own high-efficiency light for 14 hours.(Very handy after NATO surgical bombing, or after your Indymedia center has been baton-charged by angry police.)

 

"'The Solar Power Pack is a personal solar power utility designed to be operated and transported by a single person,' said Toby Kinkaid, founder and CEO of Solardyne Corporation, a developer and on-line retailer of renewable energy technology and high efficiency appliances. (Never met him; love him already.)

 

"An international traveller, Kinkaid came up with the idea for the solar backpack when he ran out of camera batteries while exploring Malaysia and the Maldives.

 

"People in the Maldives, an island nation in the Indian Ocean, use noisy diesel generators for power, said Kinkaid. Getting fuel there is difficult, as it is in all remote areas.

 

"Kinkaid studied physics in university and has been running a solar laboratory for 18 years. To reduce the cost of expensive solar electric cells (...) his Mariposa solar module uses reflectors to concentrate twice the amount of solar energy onto half the number of the solar cells. (...)

 

"The result is a solar pack that sells for $549. The solar panel is designed to last 20 years. The battery lasts for 600 charge cycles, which equals about two years if the system is used daily. Once spent, the battery can be replaced and recycled.

 

"Greenpeace ordered units for use in India. Solardyne has added a converter for Indian power that runs at a higher voltage than power in the United States. The package includes a water sterilizer powered by the solar pack that decontaminates tap water using ultraviolet rays. (Yet another post-disaster killer app.)

 

'We are particularly excited about the prospect of humanitarian organizations using the Solar Power Pack for their relief efforts,' Kinkaid said. 'Imagine the difference these groups can make in people's lives by taking a portable source of ready power to Third World nations.' (((Or G-8 nations reduced to Third World status by Wexelblat disasters.)))

 

Solar clothe

Technology News Service"

Power dressing

April 11, 02001

by Duncan Graham-Rowe "

 

Your sweater could one day provide all the power you need to run your MP3 player, mobile phone or palmtop computer == as long as you're not standing in a darkened room. "The idea comes from scientists in Germany, who have developed synthetic fibres that generate electricity when exposed to light.

 

The researchers say the fibres could be woven into machine-washable  solar clothes  to make the ultimate in portable solar cells. "The discovery may provide a big boost for developers of wearable computers, who've been plugging their devices into mini fuel cells or plain old batteries.

 

"A sail made of solar fabric might even be able to provide power for a boat's electronics, says Martin Rojahn of the Institute of Physical Electronics at the University of Stuttgart. (The same goes for a solar-fabric refugee tent. Are you listening, Burning Man Festival?) "Rojahn, Markus Schubert and Michail Rakhlin developed their photovoltaic fibres while trying to deposit amorphous silicon on curved surfaces.

 

They found that by depositing different layers around a fibre, they could build up the photovoltaic sandwich in cylindrical form. "'Any substrate that looks like a cylinder, from wires to fibre-optic cables, will work,' says Rojahn == provided it can withstand the ultraviolet radiation and 100¬°C temperatures used in the deposition process. (You don't want this done to your clothing as you're wearing it.)

 

"Power lead "

 

One of the biggest challenges facing the German team is creating contacts with each strand in a fabric, says Chris Chapman, development director of ElectroTextiles in Buckinghamshire == a company which specialises in making electronic devices out of fabric.

 

'The thing that scuppers most things with fabrics is getting power in and out of it,' he says. (Especially when your sailboat has been scuppered, and its  solar sails are shorting-out in seawater.) "As far as fashion sense is concerned, colour shouldn't be a problem, explains Rojahn.

 

Although the fibre is transparent, it can be made to take on different colours by adjusting the thickness of a transparent protective coating. (Changing color in real-time? Maybe that's too much to ask, but if it takes power, at least you've got a source.) 'Depending upon the thickness of the layer, it could be made to look blue, brown or greenish,' he says. (Military earth-colors.)

 

'Solar cloth' offers moveable power.

 

Testing a polymer layer at Heriot-Watt Textiles which incorporate solar cells could allow some travellers to dispense with batteries altogether, predict scientists. Researchers at the School of Textiles at Heriot-Watt University in Scotland say they may be able to produce fabrics carrying solar cells.

 

These, they suggest, could be rolled up and carried to remote locations - perhaps to be used as a source of power for fireman or soldiers. However, the limited space available on clothing means that jackets which provide power for mobile phones and laptops may still be some way off.

 

Traditional solar cells use layers of silicon, sandwiched between metal contacts on each side. Electron movement Solar cells work because silicon releases electrons in response to photons in the sun's rays. If one layer of silicon is treated to make it rich in electrons, and the other treated to make it contain far fewer, then a flow, or electric current can be produced between the two.

 

Most solar panels are made using crystals of silicon - which make them both expensive to produce, relatively thick, and totally inflexible. The surface area of clothing is probably only enough to power tiny sensors, rather than personal electronic equipment Professor John Wilson, Heriot-Watt University However, Professor John Wilson's team at Heriot-Watt is trying to create solar cells which are as much as 100 times thinner. He believes that a workable cell can be created by depositing thin films of silicon on to a glass substrate.

 

These films - only a few microns thick - could in theory be laid on to fabrics, or clothing fibres prior to the weaving process. Professor Wilson told BBC News Online that the textiles could be efficient enough to produce 100 watts per square metre in very sunny countries. He said: "We have completed a year-long feasibility study and we believe we can put the film on to solar fibres, and that it will work pretty well when it is there.