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Five watts are enough - Solar laptops

The new generation of solar-capable laptops and desktop computers require barely more energy than a flashlight. That is quite convincing, but development has just begun.

Too beautiful to be true! For the competition "Next-Gen PC Design," the Serbian designer Nikola Knezevic designed the ultimate solar laptop in 2008. Foldable to a small case whose outer covering is simultaneously a solar panel for charging the battery, Knezevic built a persuasive tool for use beyond all electrical connections: However, without success. He was not even selected as a finalist in the competition.
For very good reason: until now, industry has been unable to build an all-around acceptable laptop with integrated solar panel. Solar panels built into the back of the screen are capable of producing only enough energy to run a 400 MHz processor, which is not powerful enough. Another problem is that most laptop screens are not bright enough, making it necessary to use them in the shade. However, there, the batteries do not charge sufficiently.

Demand unanswered
Accordingly, until today, no supplier is able to deliver useful solar laptops. The Taiwanese manufacturer MIS announced such a machine already in 2006, for a price of 2500 US dollars, but failed to further develop it to a market-ready state. The same is true of the Spanish firm iUnika. Their extremely inexpensive solar notebook was meant to be available in summer 2009 for 320 US dollars, but is apparently still under development. No answers are given to the question of when it will be introduced onto the market. Thus, remaining for use in the off-grid area are mainly devices whose built-in rechargeable batteries can be charged by means of external solar panels, such as the OLPC-Laptop, Classmate PC 4 by Lenovo, and the Edubook Gecko by NorhTec. Such laptops were developed mainly for schools in remote areas and are characterized by the lowest possible energy consumption. They have approximately ten times less energy consumption than the average laptop on the market and nonetheless achieve comparable performances with 1 to 1.66 GHz processors.

Ninety percent less energy
The offer of desktop devices is hardly any greater. Here, too, only a few devices are available whose energy consumption is so low that they can be run with solar energy – and car batteries as cache. Among the suppliers of 12-volt desktop computers are firms such as NorhTec, SolarPC, SolarLeap, and Aleutia. The greatest differences can be found in the processors' performance capacity, which greatly influences electricity consumption – and price. On average, the devices use around 20 watts, which is approxmimately ten percent of waht the average desktop machines on the market use when operating at full speed.
Particularly interesting is that several suppliers know, from first-hand experience, what is required of computers in third-world countries: For example, Mike Rosenberg, CEO of the firm Aleutia founded in England in 2006. Rosenberg had previously opened an internet café for street children in Ghana and thereby learned what is needed. Due to a lack of offers on the market, Rosenberg decided to take the matter into his own hands and created a palette of solar-capable desktop devices that are now sold in 59 countries.
Charles Watson has a similar, direct connection to the theme. The young American had already dedicated himself to solar powered desktop devices during his high school days. He then traveled to Nepal and saw what school children in rural regions were lacking. Watson subsequently founded the non-profit organization SolarLEAP in Hong Kong in 2009 and began building desktop machines that are meanwhile in use in Nepal, Ghana, India, and also in Ethiopia – for the Solar Energy Foundation. Worldwide, 1.6 billion people have to make do without electricity, which opens up a huge market whose demands are not satisfied by the currently available devices. Solar cracks like Rosenberg and Watson still have a lot of work ahead of them.

Christian Schmidt is a scientific journalist in Zurich.

Source: sun-connect 6 | July 2011 (p. 4-5)