#### Comment Preferences

• ##### And more directly(14+ / 0-)

P = R* I^2

or

P = R / V ^2

which is what gives you the 6x decrease in power loss for a 2.5x increase in voltage (resistance of the cable is the same).

[ Parent ]

• ##### Actually, the second equation is:(6+ / 0-)

P = V^2 / R

and I'm not sure how you draw the conclusion you do.

The man who moves a mountain begins by moving away small stones. -Confucius

[ Parent ]

• ##### You're right(5+ / 0-)

I screwed up the 2nd equation, but it's important to realize which V you're talking about. When it comes to losses in the transmission line, the V is the voltage drop across the line (which will be lower at lower I), not the input voltage.

So, at higher voltage at constant delivered power, the current will be lower and the reduced power loss will go like the square of the decreased current.

[ Parent ]

• ##### Here's a link to a handy ohms law calculator(1+ / 0-)
Recommended by:
kyril

usually the square chart is shown as a circle, but all the formulas are correct.  There are also some 3 phase AC formulas that one might find useful.

http://www.angelfire.com/...

Google Ohm's Law Calculator to find more.

Republicans are like alligators. All mouth and no ears.

[ Parent ]

• ##### You also need to change the transformer at each(2+ / 0-)
Recommended by:
goodpractice, kyril

end of the powerline to both boost the voltage on the line, and to step it down to distribution useful voltages, like 13,800 line to line, 7200 line to neutral distribution lines and such.

The transformers in the switchyard also have to have sufficient distances between phases to handle the magnetic forces that are generated, so it isn't as easy as it may seem, just to boost voltage.  Before it can be done, there is also an arduous and fairly long term process to modify standards for cross country powerlines and towers before this kind of change can be implemented.  So the regulatory environment must also change as well as the crossbars.  Much study for wind and ice loading, capacitance, effects on power factor correction and a lot more needs to be done before changes can be made.

But I like the idea, and agree with the higher efficiency of high voltage long distance power transmission.

Republicans are like alligators. All mouth and no ears.

[ Parent ]

• ##### In general(2+ / 0-)
Recommended by:
kyril, Ohiodem1

our national grid is long overdue for an upgrade, and boosting long-haul interconnections is going to be a major part of any strategy that relies on localized renewable sources.

Seems like a good time to revist the 'standards' for high voltage transmission and make the needed changes to reduce transmission losses, especially if it can be done relatively cheaply.

[ Parent ]

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