Solar cell panel prices to drop soon..

[NeilBlanchard]

Hi Rich,

I dunno -- that doesn't sound right. Volts X Amps = Watts is what I was taught.

[Ryland]

[QUOTE=Xringer;61712]

Originally Posted by WisJim

Here ya go!
Watt - Wikipedia, the free encyclopedia
The watt (symbol: W) is the SI derived unit of power, equal to one joule of energy per second. It measures a rate of energy use or production.

Wikipedia is correct, you just didn't read the rest of it.

to quote Wikipedia:
"Confusion of watts and watt-hours

Power and energy are frequently confused in the general media. Power is the rate at which energy is used (or generated). A watt is one joule of energy per second. For example, if a 100 watt light bulb is turned on for one hour, the energy used is 100 watt-hours or 0.1 kilowatt-hour, or 360,000 joules. This same quantity of energy would light a 40-watt bulb for 2.5 hours. A power station would be rated in watts, but its annual energy sales would be in watt-hours (or kilowatt-hours or megawatt-hours). A kilowatt-hour is the amount of energy equivalent to a steady power of 1 kilowatt running for 1 hour, or 3.6 megajoules."
And the definition of Joule:

joule (jūl, joul) pronunciation
n. (Abbr. J or j)

1. The International System unit of electrical, mechanical, and thermal energy.
2.
1. A unit of electrical energy equal to the work done when a current of one ampere is passed through a resistance of one ohm for one second.
2. A unit of energy equal to the work done when a force of one newton acts through a distance of one meter.


So if you read both of them it becomes very clear that a Watt is not a watt second, because then a watt hour would be a watt/second/hour, and that would be kind of like giving speed in miles per second per hour...

[Xringer]

Originally Posted by NeilBlanchard

Hi Rich,

I dunno -- that doesn't sound right. Volts X Amps = Watts is what I was taught.

That's right.

A volt is a potential. It's kinda like air pressure in a tire.
It's at 44 PSI, but it's not doing any work, it's just sitting there.

An Amp is not the same thing. It's the amount (count) of electrons that flow past a point(like an Amp Meter) in a circuit for one second.

Like water flowing in a hose.. The Amp meter is like the GPM meter on a fire engine. Only, it's coulombs per second.


If you have a 12V battery and 6 ohm soldering iron, that iron is going to draw 2 Amps off the battery. V/R=A or (I=E/R)
The iron will heat up and output 24 watts of heat, every single second. (current squared times the resistance in ohms).
If you only turned on the iron for 1/2 a second, it would dissipate 12 watts (as heat).

If you sat there flipping the switch off 1 sec and back on 1 sec repeatedly,
the average wattage(over time) used by the iron would be 12W.

[Xringer]

[QUOTE=Ryland;61723]

Originally Posted by Xringer

Wikipedia is correct, you just didn't read the rest of it.

to quote Wikipedia:
"Confusion of watts and watt-hours

Power and energy are frequently confused in the general media. Power is the rate at which energy is used (or generated). A watt is one joule of energy per second. For example, if a 100 watt light bulb is turned on for one hour, the energy used is 100 watt-hours or 0.1 kilowatt-hour, or 360,000 joules. This same quantity of energy would light a 40-watt bulb for 2.5 hours. A power station would be rated in watts, but its annual energy sales would be in watt-hours (or kilowatt-hours or megawatt-hours). A kilowatt-hour is the amount of energy equivalent to a steady power of 1 kilowatt running for 1 hour, or 3.6 megajoules."
And the definition of Joule:

joule (jūl, joul) pronunciation
n. (Abbr. J or j)

1. The International System unit of electrical, mechanical, and thermal energy.
2.
1. A unit of electrical energy equal to the work done when a current of one ampere is passed through a resistance of one ohm for one second.
2. A unit of energy equal to the work done when a force of one newton acts through a distance of one meter.


So if you read both of them it becomes very clear that a Watt is not a watt second, because then a watt hour would be a watt/second/hour, and that would be kind of like giving speed in miles per second per hour...

Does "a watt" mean 1 watt?? (Like if you say, "a pound", you mean 1.0 lbs.).?.

"The watt (symbol: W) is the SI derived unit of power, equal to one joule of energy per second. It measures a rate of energy use or production."

As in E x I=P..

I'm not sure that anyone here is confused about the KWH on their electric bills.
And I have no clue as to why someone added that extraneous info to the definition of the Watt.

Maybe I should go delete that part out.?.