What is the most EFFICENT use of 12 Volts, in plate design?

[mario brito]

from wiki :

"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. 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:

(1 kW·h)(1000 W/kW)(3600 s/h) = 3,600,000 W·s = 3,600,000 J = 3.6 MJ."

[Stratous]

It takes 1 second for a 100 Watt bulb to "use" 100 Watt-seconds of power.


That is why a 100 Watt bulb burns brighter than a 60 Watt bulb.

The bulb is running AT 100 Watts from the moment of turn on.

If it ran for 10 hours, it would consume a Kilo-Watt Hour of power.

BoyntonStu

I must be dense because that doesnt make sense to me. 1 second for 100 watts = 360000 watts per hour? Or if I read a book for 5 hours under a 100 watt bulb, I would have consumed 500 watts, correct? which then would be 1Kwatt for 10 hours.

[Stratous]

I must be dense because that doesnt make sense to me. 1 second for 100 watts = 360000 watts per hour? Or if I read a book for 5 hours under a 100 watt bulb, I would have consumed 500 watts, correct? which then would be 1Kwatt for 10 hours.

Ok, so 1w/hour is 3600 watts? which means an electrolyzer consuming 50 watts would use 180000 watts or .5w/h is this correct?

[BoyntonStu]

I must be dense because that doesnt make sense to me. 1 second for 100 watts = 360000 watts per hour? Or if I read a book for 5 hours under a 100 watt bulb, I would have consumed 500 watts, correct? which then would be 1Kwatt for 10 hours.

The kilowatt hour, also written kilowatt-hour,[1] (symbol kW·h, kW h or kWh) is a unit of energy.[2]

Energy delivered by electric utilities is usually expressed and charged for in kWh.

The kilowatt hour is not used in the International System of Units (SI); the SI unit of energy is the joule (J), equal to one watt - second.

Note that the kWh is the product of power in kilowatts multiplied by time in hours; it is not kW/h.


BoyntonStu

[bobcampbell]

What was the source voltage?
Efficiency is best compared and stated with units of liters per minute per Watt. I don't know what a Watt Minute/Liter is.

The source voltage is two large batteries in my diesel truck with a small 10A battery charger attached so that I can continue to draw from the batteries and still start the truck in the morning. It supplies 13.7 Volts

I hope the explanation of Watt Minutes that I gave earlier today made sense. It's just a more precise way of expressing a unit of work.
This is the amount of energy transferred if work is done at an average rate of one watt for one minute.

Bob Campbell

[bobcampbell]

i believe that Amps are always measured in hours. but i'm not the best person for this answer.

Wow this topic has taken on a life of it's own.. Yeah you have it. Batteries are measured in Amp Hours. With batteries it is assumed that the voltage will be 12v or whatever it is for that type of battery. Electricity is sold in Kilo Watt Hour. It is the amount of work that can be done using 1000 watts for one hour. A Watt minute is the amount of work that can be done in one minute using one watt.

If you look at the math formulas that I gave as examples you will notice that there is a unit of time multiplied by the number of watts divided by volume.

Hence it is Watt Minutes per Litter. It's nothing to worry about as the figures everyone uses are always assumed to be per minute. This is just a more precise description.

Bob Campbell

[bobcampbell]

If I understand correctly, it takes 1 hour for a 100 watt light bulb to use 100 watts. Is this correct?

The light bulb uses 100 Watts. The amount of energy it uses depends on how long it uses 100W. If it is left on for 10 hours it will use 1 Kilo Watt Hour.

Respectfully,
Bob Campbell