April 20: Our Carbon Footprint
posted by John Green @ Friday, April 20, 2007
8 Comments
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8 Comments:
John--I've been unable to comment on the Brotherhood2.com site. Is there a trick? Ed and I loved seeing Barry and Libba at the Prom!
Ann in Michigan
Ann, there shouldn't be a trick. It should be pretty easy...after you enter your comment, you just put your information in and then hit post. Can you describe the problem you're having?
Thanks,
John
I just found this site called Gizoogle that "-izzles" websites -- adding "-izzle" or "-izz" to words. I Gizoogled my book blog to see what would happen. OH MY. My most recent post discussed Looking for Alaska, and Gizoogle totally warped it.
I wrote:
Looking for Alaska by John Green
Looking for Alaska is about a girl, not a state. It's also about a boy, but it's not your typical boy-meets-girl story. Boarding school, friends, famous last words, and before and after all factor in this dramatic and engrossing tale. John Green's debut novel is about a search for self, and it's a story readers won't soon forget.
Gizoogle's version:
Chillin' fo` Alaska by Jizzle Green
Look'n fo` Alaska is `bout a girl, not a state . Death row 187 4 life. It's also `bout a boy, but it's not yo typical boy-meets-girl story ridin' in mah double R. Pimpin' school, friends, famous last words, n before n afta all factor in this dramatic n engross'n tale . Boo-Yaa!. Jizzay Green's debut novel is `bout a search fo` sizzay n it's a story reada won't soon forget and my money on my mind.
Um, yo?
Hey John,
I'm sorry to do this but... I have to point out that the Watt is a unit of power, not energy. Measuring the amount of energy a computer uses in an hour in Watts is like describing how far you walked by the speed you were going.
The unit of energy that you will find on your electric bill is the kilowatt-hour. You can convert from the instantaneous power consumption of a device in Watts to the energy that thing uses in an hour in kilowatt-hours by multiplying by 3.6 (that's 3600 seconds in an hour and 1000 kilowatts in a watt).
--your friendly neighborhood physicist
@blake,
Interestingly, I think John managed to do the calculations correctly without really knowing what he was talking about, or even using the correct terminology.
So when he said computers use "110 watts in an hour," that was wrong... it should have been more "110 watts *for* an hour."
But then he went ahead and multiplied 110 watts by all the hours that people spend watching B20...and thus actually (accidentally) got himself into the correct units (watt hours) and then even managed to correctly convert into kilowatt hours.
At least...I think that's how it works. If I'm still wrong, let me know, it'd be a good thing for me to be sure about.
I think, but am not positive, that he'd only have to multiply by 3.6 if he started out in watt-seconds (joules) because then he'd have to get himself into hours and kilowatts all at once.
Embarrassingly, I must admit that I too got my units wrong in my comment. If you multiply by 3.6 you effectively convert the instantaneous power in watts to an energy in kilojoules, not kilowatt-hours.
So, yes... when John multiplied the power a computer uses by the time it is being used, he gets an energy in watt-hours.
I'm curious as to the origin of John's statement that on average computers use 110 W of power. Desktop computers certainly use more (the average power supply is somewhere around 300 W, though it doesn't necessarily draw its full capacity all the time). I would estimate that a desktop uses more like 200 W of power. The monitor also consumes power, though flat screen LCDs are far more efficient than the old CRTs. My LCD apparently draws 42 W of power. So, let's say that a desktop system uses about 250W. A laptop uses far less power, often something in the 60-80 W range. So, to actually calculate the energy use of your video blog viewings you would need to know the ratio of desktop to laptop viewers.
If your viewership were entirely composed of people in college or older, I think we could safely assume a 80%+ laptop usage. However, I would imagine that John draws a large number of high school viewers from his tours, and those kids probably are viewing from the desktop at home or in the computer lab at school.
For the sake of argument let's say that there is a 50-50 split of laptop and desktop users. Then the average power consumption of a viewer would be:
0.5*(250W + 70W) = 160W
which is roughly 40% higher than John's number. So, you might want to add a couple more pennies to your carbon fund.
Computer wattage is highly variable, so disputing it is kinda moot. FYI; BAVC (bigass video cards) use a ton of power.
You can get a wattmeter that plugs into the wall and the computer plugs into if you want the exact amount. (plug in your power strip if you want the monitor power combined)
Watch for the dongles. (all those little power adapters for things) They add up after a while, and usually get left plugged in all the time, so they use power 24/7.
Lights are the most inefficient devices. Get LED's if you can. Please.
I want to marry you!
no, but actually, to put the cream on top of all the environmantal awareness videos i've posted on my myspace with calculating the carbon footprint of watching them in hopes that apx 1% (an optimistic number) of the viewers who care might counter it gardening. instead, i will use yours, so thanx. -andrea
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