|
| |
Engineering Feats
> I'm Dreaming of a Green Christmas
As the public has become more environmentally conscious, more and more of Americas icons are going green. This year was a banner year for one such icon. |
|
|
|
Originally, and for decades afterwards, the National Christmas
Tree in Washington, DC was chosen from trees grown in various states. The tree was chopped down and trucked to Washington. |
|
|
Twenty-eight years ago, a live tree was planted
which now serves as the national tree each year. This year, an engineering feat made the tree a little greener. What was the innovation on this years tree?
|
| |
|
For the first time ever, the National Christmas Tree was lighted with over 20-thousand energy-efficient light-emitting diodes or LEDs. The LEDs are brighter and twinkle in colors that were not previously available in incandescent bulbs.
And, they are far better for the environment, using only about 10 percent of the energy of standard bulbs. Beyond the savings, they are always cool to the touch and are almost indestructible. Perhaps best of all, if one goes out, the rest of the string stays lit.
LEDs are created from semiconductors and changes in the makeup of the semiconductor changes the color of the light that is emitted. Over the past couple of years, LEDs have begun to slowly enter the consumer marketplace. So now, the average person can also make his white Christmas a little greener.
|
| |
|
