Wednesday, September 24, 2008

New Solar Cell Process Saves $$$

Univ. of Utah Students Cut Germanium for Solar Cells

University of Utah engineers devised a new way to slice thin wafers of the element germanium for use in the most efficient type of solar power cells. They say the new method should lower the cost of such cells by using less raw material and reducing waste.

Germanium solar cells, the most efficient solar cells, now are used mainly on spacecraft, but with the improved wafer-slicing method, "the idea is to make germanium-based, high-efficiency solar cells for uses where cost now is a factor," particularly for solar power on Earth, says Eberhard "Ebbe" Bamberg, assistant professor of mechanical engineering.

Dinesh Rakwal, a doctoral student in mechanical engineering, adds: "We're coming up with a more efficient way of making germanium wafers for solar cells - to reduce the cost and weight of these solar cells and make them defect-free."

Bamberg and Rakwal are publishing their findings in the Journal of Materials Processing Technology. Their study has been accepted, and a final version will be published online late this month or in early October, and in print in 2009.

Their novel process uses a brass-coated, steel-wire to slice round wafers of germanium from cylindrical ingots. The brittle germanium cracks easily, requiring a saw with a soft touch. The width of the saw creates waste. In the past a significant amount of germanium is lost during the cutting process. The new U of U sawing method improves efficiency by about 10%.

The new method for slicing solar cell wafers - known as wire electrical discharge machining (WEDM) - wastes less germanium and produces more wafers by cutting thinner wafers with less waste and cracking. The method uses an extremely thin molybdenum wire with an electrical current running through it.

More Info at: U of Utah

Check Out: Sustainable Design Update

Saturday, September 06, 2008

New HP Laptop - 97% Package Free!

HP - Laptop Without Box

I saw this over at Gizmodo and thought it deserved to be a Friday post.

From Gizmodo:

We've seem our share of good packaging ideas and bad packaging ideas, but this new method from HP is a great packaging idea. Their Pavilion dv692 systems available at Wal-Mart and Sam's Club will sit on the shelf in their own recycled material messenger bags, stabilized and protected with internal air bubbles. This alternative to huge boxes shoved full of styrofoam has reduced HP's individual consumer packaging by an outrageous 97%.

Via: Gizmodo