Thursday, September 17, 2015

The power through

Power lines
High tension power wires bring electrical energy across vast distances for distribution to the end users.  They play as the major energy conduits of today's civilizations.  With the advent of information technology, the world's hunger for electrical power became even more resounding.  So what makes this system work?

1.  AC is used instead of DC.  AC allows voltage transformation.  This means that the voltage can be varied with the use of a device called a transformer.  A higher voltage is used for transmission versus the lower voltage used in distribution.  Why is this so?  This leads us to point number 2.

2.  As power (P) is the product of voltage (E) and current (I), for the same power transmitted, the current can be lower by using higher voltage (P= IE).  A lower current means smaller diameter transmission cables.  This translates to lower investment costs for the cables.

3.  The consequence of higher voltage however is the difficulty of isolation or insulation.  If the cables are too near each other, it can cause arcing much like a lightning bolt.  Thus the cables are raised high above ground and are spaced far apart enough.

Modern electrical transmission systems are more complex than it seems.  There is normallty a grid designed to take in power from many source generators and distribute the power across multiple load points.  All these complications are taken cared of by engineers so that we can live our lives comfortably and with all the power we need.