Tuesday, July 29, 2014

Coming to a seashore near you: Clean waterways using the sun!

Photo courtesy Andrew David Thaler
Check out this technology! There are at least one billion tons of plastic in the ocean. Wouldn't it be great to be able to collect this plastic before it gets to the ocean and is more difficult to clean up?

This solar-powered water wheel may be used to clean debris from water and can transfer this debris to a barge. Check out this site for more information!

P.S.: I just came across this video. It's good for a laugh.

Monday, July 21, 2014

What is a semiconductor?


"Monokristalines Silizium für die Waferherstellung". Licensed under Creative Commons Attribution-Share Alike 3.0 via Wikimedia Commons
A semiconductor is a material that typically conducts electricity better than an insulator, but not as good as a metal. Electrons in the material can move around, but, in order to move around, they must overcome an energy barrier. Things at higher temperatures have more energy. Some electrons in a semiconductor are able to overcome the energy barrier (between what are known as the valence and conduction bands) and move. Dopants (other added elements) can be added to the material to change the electron concentration. Places where an electron is absent but is of low enough energy that an electron "should" be there are known as holes. It is these mobile electrons and mobile holes (absences of electrons) that conduct electricity. Semiconductors are widely used to make solar cells as well as computer chips. They are extremely useful materials.

Saturday, July 19, 2014

TED talks solar

Check out these interesting TED talks on solar power!

1. Donald Sadoway, Professor of Materials Chemistry at MIT


2. Sanjit 'Bunker' Roy, founder of Barefoot College


3. Bill Gross, founder of Idealab


Recommended by Community Renewable Energy.