[Gllug] OT: Merging UPS outputs

[Daniel P. Berrange]

On Thu, Aug 18, 2005 at 05:23:49PM +0100, Dylan wrote:
> On Thursday 18 Aug 2005 00:15, Richard Jones wrote:
> > Why do we run 240 VAC through our houses anyway?  Surely all of these
> > transformers and regulators must waste huge amounts of energy.

Also check out this Wikipedia article

http://en.wikipedia.org/wiki/Alternating_current

"Use of a higher voltage leads to more efficient transmission of power. 
 The power losses in a conductor are a product of the current and 
 resistance, described by the formula P = I2R. This implies that in 
 the same wire, if the current is doubled, the power loss will be four 
 times greater. Therefore it is advantageous when transmitting large 
 amounts of power to distribute the power with extremely high voltages 
 (sometimes as high as hundreds of kilovolts). However high voltages 
 also have disadvantages, the main ones being the increased danger to 
 anyone who comes into contact with them, the extra insulation required, 
 and generally increased difficulty in their safe handling. In the power 
 plant the voltage is generated on three phase low voltage, with a 
 frequency of either 50 or 60 Hertz, and stepped up to a high voltage 
 for distribution and stepped down, with a neutral, to a relatively low 
 level for the consumer, generally around 200 V to 500 V between phases 
 and 100 V to 250 V between each phase and the neutral."

Dan.
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