In 2015, American consumers will finally be able to purchase fuel cell cars from Toyota and other manufacturers. Although touted as zero-emissions vehicles, most of the cars will run on hydrogen made from natural gas, a fossil fuel that contributes to global warming.
Now, scientists at Stanford Univ. have developed a low-cost, emissions-free device that uses an ordinary AAA battery to produce hydrogen by water electrolysis. The battery sends an electric current through two electrodes that split liquid water into hydrogen and oxygen gas. Unlike other water splitters that use precious-metal catalysts, the electrodes in the Stanford device are made of inexpensive and abundant nickel and iron.
The new transparent solar cells are made from tiny organic molecules that absorb invisible wavelengths of sunlight such as ultraviolet and near infrared light. This invisble light is then guided to the edge of the solar panel, where thin strips of photovoltaic solar cells pick it up and convert it into energy. "Because the materials do not absorb or emit light in the visible spectrum, they look exceptionally transparent to the human eye," Lunt said.