What is a watt?

[FalconFour]

I just came up with this on Facebook - every word and every calculation. Thought I should share so it'll last a little longer on the internet.

What is 1W (1 watt)?
1 watt is a tiny LED nightlight. 1 watt is the indicator light on the front of a power strip. 1 watt of power, all hours around the clock, 24 hours a day, 7 days a week, 365 days a year, would cost you 8.87 kWh ($1.24) a year on your power bill, or 0.7 kWh ($0.10) per month. So don't bother unplugging those cell phones chargers. Seriously.

What is 10W?
A tablet PC, charging (not full - they use much less when full and still plugged in). Your cable box. An old digital alarm clock. Your cable modem and router. 10 watts around the clock costs you 87.7 kWh ($12.28) a year on your power bill... or 7.3 kWh ($1.02) per month.

What is 100W?
One bright incandescent bulb (100W bulb). A modern desktop PC and monitor - both running. Your TV. A high-end laptop, charging (not full). A standard-sized refrigerator or freezer. About the amount of power as a weed whacker. 100 watts around the clock costs you 876.6 kWh ($122.72) a year... or 73.05 kWh ($10.23) a month...

What is 1kW (1 kilowatt, or 1,000W)? (Note: NOT "kWh")
A fan-heater. A coffee pot. Anything in the kitchen that makes heat. The limit of a 120v outlet is 1,800 watts. A clothes dryer uses around 3,000 to 4,000 watts while it's running. 1 kilowatt - rarely used in any case longer than a few minutes except in a clothes dryer. It's also about as much power as a lawn mower engine. 1kW around the clock would cost you 8765.8 kWh ($1,227.21) a year... or... 730.5 kWh ($102.27) a month.

How about 10kW (10 kilowatts, or 10,000W)?
Nothing in your house. I mean, except some very rare things... nothing uses 10kW for very long. House wiring isn't even rated for that, anywhere but the service line to your power meter. That's... well, we're getting close to that with some EV chargers like the Tesla Model S - and that's only for a few hours, not near around the clock. The Prius electric motor, I believe, is around 10kW, at least the total between the two electric motors. I'd imagine some commercial roof-top air conditioners would use 10kW or more. Now, if this were around the clock... that'd be 87658.1 kWh ($12,272.14) a year. Or 7304.8 kWh ($1,022.68) a month. Ouch. Or do you have a 10kW solar system on your home? Whenever there are daylight hours - about 50% of the time on average - imagine half that is now money you made from 10kW.

Good god. What about 100kW (100 kilowatts, or 100,000W)?
Yeah, that's the motor in the Nissan LEAF at full throttle, 90kW. About as much power as a car engine revved up. The power that drives large water pumps, heating and cooling systems, etc. Cost and consumption at this level goes on to the "grid thinking" scale - think of whole city blocks and a steady load. Ready for this? That level of consumption is about 876581.3 kWh per year, costing $122,721.38 at $0.14/kWh.

And we've reached the peak. Right? What about 1MW (1 megawatt, 1,000 kilowatts, or... yep, 1,000,000 watts)?
About 0.0047% of the current energy demand of California (22 GW).

Scale.

 

[FalconFour]

I can't edit the Facebook post, but I'd gladly post edits for any corrections found later. Didn't have anything to reference, so these numbers are mostly top-of-head figures. Not 100% sure on the 1,800 watts from a wall outlet, though - I know it's limited by amps, but not sure on where the line's drawn on watts (I know it varies by the type of load, too)...

 

[adric22]

I'd have to disagree on a few of these. An LED indicator does not use 1 watt. Those would normally be measured in miliwatts. Also, I think a refrigerator uses more than 100 watts when it is running. Probably close to 1,000 watts. But maybe if you are looking at the load averaged over a whole day or something it might be 100 watts.

 

[ksnogas2112]

+1

 

[lukati]

Also, I think a refrigerator uses more than 100 watts when it is running. Probably close to 1,000 watts. But maybe if you are looking at the load averaged over a whole day or something it might be 100 watts.

I have a TED energy monitor and my refrigerator (a very standard recent model) uses 125W when the compressor is running.

 

[ENIAC]

Here's a table with far more accurate wattage consumption by device.

So don't bother unplugging those cell phones chargers. Seriously.

In my opinion you should unplug your chargers when not in use, as well as all other vampire load for that matter. It's not just the 8.87 kWh for the year for your one phone that's the big issue, it's also the other hundreds of millions of other mobile phones in the country also wasting electricity. Or, you could look at it as that 8.87 kWh is a free day or two commute per year in your LEAF, if you simply unplug your mobile phone charger.

Here's another interesting factoid...
Energy Vampires silently suck away more than $5.8 billion of extra energy annually.
This wasted energy sends more than 87 billion pounds of CO2 into the atmosphere each year.
http://alexandriava.gov/tes/gbrc/default.aspx?id=48294" onclick="window.open(this.href);return false;

 

[hill]

What?




http://en.wikipedia.org/wiki/Watt" onclick="window.open(this.href);return false;

 

[garygid]

Watt did you say?
It dropped in the water, and now it's all watt.
No, I don't watt none'o that.
Is that a watt growin' on yer nose?
Careful, that looks like a watt's nest!


If everybody in the USA would pee in the garden just once
each day, instead of using and flushing the toilet, that would
save around 120 billion (about 300 x 400,000,000) gallons of
drinking water annually, save processing sewerage, and
provide much-needed fertilizer for our gardens, not to mention
saving the electricity needed to pump and purify to water
and pump and process the sewerage.

 

[DeaneG]

YMMV-
I thought cable boxes were closer to 30 watts (continuous).
My PC is around 100 watts, plus another 100 watts for the monitor.
My plasma TV is 500 watts.

 

[EVDRIVER]

My hot tub could draw 6-7kw, it is now gone.

 

[FalconFour]

You guys are awesome. :lol:

OK, it wasn't meant to be an accurate tit-for-tat of various devices. It's not meant to say "a TV is 100 watts", but rather that "100 watts is like a TV". It's mostly for the 99%-or-so of people in the world that have no freakin' clue what a watt is and why their bill is so high. There are a loooooooooooot of those people in my experience. Sad but true.

So the point of this whole "scale" post is how large these numbers are - and why one cell phone charger is like pissing in the ocean - no matter how many people piss in it, the ocean's not gonna become piss. :lol:

To scale... if 315,148,795 people (the "population clock" of the U.S. as of this post) unplugged their 0.1-watt cell phone chargers when they're not being used (as has been tested - they use NO power),
... assuming there are even 315,148,795 cell phone chargers in the entire country that would be all plugged in at once...
... you'd save 31,514,879.5 instantaneous watts (31.5 MW), or 0.15% of California's power (for ALL chargers in the U.S.), or with a rough Google estimate, 0.01% of the whole country's power usage. Round to the nearest tenth of a percent. 0.0% of the country's power problem would be solved by unplugging EVERY unused charger in the country.

Sorry to run the numbers and prove it, but that's why I concentrate on the bigger things - like the countless ignorant people still continuing to buy (and complain about the lack of) incandescent bulbs that produce light as a byproduct of the heat they produce. Horrible waste. And all the stores, supermarkets, etc., that have huge rows of fluorescent lights each using 30-40 watts per bulb. Outdated technology. That's what's the killer consumer in this country, maybe even the world...

 

[cwerdna]

Sorry to run the numbers and prove it, but that's why I concentrate on the bigger things - like the countless ignorant people still continuing to buy (and complain about the lack of) incandescent bulbs that produce light as a byproduct of the heat they produce. Horrible waste. And all the stores, supermarkets, etc., that have huge rows of fluorescent lights each using 30-40 watts per bulb. Outdated technology. That's what's the killer consumer in this country, maybe even the world...

Yeah... in an energy efficiency in building system class I took, the lighting designer guest lecturer referred to incandescent bulbs as heaters w/the side effect of producing light.

As for the bolded part, are you complaining about the tube fluorescents being outdated (e.g. T8 and T12 bulbs)? If so, vs. what any why? Or, are you just complaining that they're overlit?

 

[FalconFour]

As for the bolded part, are you complaining about the tube fluorescents being outdated (e.g. T8 and T12 bulbs)? If so, vs. what any why? Or, are you just complaining that they're overlit?

Yeah, just over-lit. I don't know of any better lighting technology aside from very expensive LEDs that offer a marginal improvement over fluorescent which are already pretty efficient. An important premise that many lighting designers seem to forget is that if you put a solid box around a light bulb, none of that light escapes the box and the "box" will be a net-zero-efficiency box that just produces heat - even though there's tons of light being produced inside. So you might have efficient bulbs, but if the lights aren't installed in appropriate places the light can access, you end up just wasting energy. Lots of it.

And most supermarkets have high ceilings covered every inch in tubes. Yet the ceiling blocks out the sun (creating that "zero-efficiency box" from the outside in, now needing to be lit from the inside), and the store is open primarily during daylight hours. It's just stunning how wasteful that is...

 

[kentuckyleaf]

Nice post about a watt. A watt is also one volt at one amp. 120 volts at one amp is 120 watts. A moderen UHF television transmitter transmits at 1,000,000 watts effective radiated power, but it doesn't consume a million watts due to the gain of the antenna. ERP assumes a sphere of power is transmitted, but we attempt to transmit pancakes shapes instead. Actual continuous consumption of the TV transmitter facility is roughly 175kW. A moderen television transmitter in Kentucky will consume over $10,000 worth of electricity a month. While that seems like a large power bill, this breaks down to about two cents a month per household in the Lexington KY DMA. A properly sized emergency generator at the transmitter would produce at least 300 kW of power, which is the same as 60 five kilowatt generators that a homeowner might purchase during an ice storm. All this is off topic about the Nissan Leaf, but it troubles me that something as basic and important as a "watt" is not part of the primary education process. Maybe it is nowadays, seeing how we need everyone to at least understand why there is a need to "go green." Saving watts saves green, the kind you carry in your wallet!