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143 Comments
- nahsrocketeer75, on 12/04/2008, -3/+108I'm getting one of those for my house. Given how many times my kids come in and out, it would probably generate electricity for the whole neighborhood.
- doiveo, on 12/04/2008, -1/+92"Your mama eats so much, if they put a generator on her fridge door they would solve the energy crisis"
- marklad2020, on 12/04/2008, -1/+54This sounds perfect. The door generates enough power to make a cup of coffee. Fully offset coffee. Maybe if you go around the door twice you can get carbon credits??
- vandan2, on 12/04/2008, -2/+40Everyone should go round ten times to offset all the water being wasted by Starbucks
- FindTheGreen, on 12/04/2008, -2/+39I love the idea of offsetting the energy used in making a cup of coffee just by walking through the door. This has potential to not only make the restaurant carbon-neutral using the energy of customers, but their profits will increase as well.
- thegrantman, on 12/05/2008, -1/+36You spin the door..you get coffee.
You get coffee...you spin the door faster.
You spin faster and get more coffee.
I introduce the latest in exercise equipment...
The Mr.Coffee Cross Trainer. - EcoPanas, on 12/04/2008, -1/+30It is little step like these that can lead to much bigger change!
- gypsywine, on 12/04/2008, -1/+26It's great that something as simple as walking though a door can help to offset everyday things. I can't wait to see how this idea expands!
- swissgeek, on 12/04/2008, -1/+20If this really generates energy that sounds like a good idea...
- jgzman, on 12/05/2008, -0/+16That helluvalot more is if you want to boil it away, not just bring it to a boil. That's not so good for coffee, although I can see coffee vapor being the new thing.
1 cup =237 mL
1 cal = 1 mL raised 1C
237 cal = 1 cup raised 1C
237 cal = 731 foot-pounds. (that is, 731 pounds pushed one foot, or one pound pushed 731 feet, or similar)
Tap water is generally as hot as 40C. We need to raise it 60C.
731 ft-lb * 60 = 43860 ft-lb.
Assuming that a door is pushed five feet, (kind of large, I would say) and a device that captures and transmits directly to the water 100% of the energy, (well beyond impossible) it would require you to apply 8,772 lb of force to the door to bring a single cup of water to boil.
That's pretty much what Dubiousness claimed, if you take into account the different assumptions.
To conclude: nice idea. Not as advertised. - ryan83189, on 12/05/2008, -0/+16It must be hard as hell to push, thats a lot of calories/joules/btu to heat that water.
- emjaymj, on 12/05/2008, -0/+13You mean sex is the only thing keeping the kids he already has alive?
- pjosemroy, on 12/04/2008, -2/+15If we can add more innovative equipment to the fitness centers where one can see many moving things, it can produce energy to power the whole center, perhaps an extra for selling.
- dubiousness, on 12/05/2008, -0/+13To raise the temperature of a cup of water by 70 C (almost to boiling), more than 5,000 lbs of force, assuming awesome energy efficiency and pushing for about 10 feet. A helluvalot more if you want to actually boil it.
- malanic, on 12/05/2008, -2/+14I call BS.
I remember that light that won a school contest. It was just a concept and it was gravity powered. You had to lift a weight to make it work, but he hadn't done his sums right and the amount of energy you'd have to put in was prohibitive.
I reckon you'd have to pedal a generator for quite some time to boil a cup of water. The power from your point would take a couple of thousand watts, for a minute or so, so you'd have to pedal for at least five minutes I'd say.
There's no way you could do it from one push of a revolving door. - uncoveror, on 12/05/2008, -1/+13FYI. The terms "The Netherlands" and "Holland" are not interchangeable. The Netherlands has 12 provinces, two of which are North Holland and South Holland. Zeist is in neither of those. It is in Utrecht. The more you know!
- beyonddarwin, on 12/05/2008, -1/+11Just proud that it's the Netherlands again to set an example :-)
as with marijuana, abortion, euthanasia and gay marriage.
BTW you can vote on this stuff at http://www.globalopinion.eu
o.. and don't forget the dikes ;-) - Sail3, on 08/04/2009, -1/+11ADD kids + revolving door = energy crisis solved
- Murdats, on 12/05/2008, -0/+10it is probably considering the fact the water is already hot and it takes much less power to maintain the temperature.
that or they may just be counting the energy used for the pump that pushes the water through the coffee - TNsmokyjoe, on 12/04/2008, -2/+11I wonder how hard you have to push to get the door to move?
- gianthorse, on 12/05/2008, -0/+8nice..havent heard an original mama joke in awhile
- laim, on 12/05/2008, -0/+8you mean 40 000 Newtons one meter, which is roughly 4 000 kg. still a lot though, i see your point
- wilf_brim, on 12/05/2008, -1/+8"generates enough energy to make a cup of coffee". Unless that door weighs about a ton, I call *****.
- gavinhudson, on 12/04/2008, -0/+7ha - I don't know about my house, but this would be awesome for just about every office building. Maybe for the home (or professional kitchen where waiters instead of kids run in and out) the flap doors could be used in the same way?
- Myztry, on 12/05/2008, -0/+6A heavy flywheel would be great for crushing people who only manage to get halfway inside before the gap closes.
- DrewPeacock, on 12/05/2008, -0/+6Then "Each time you pass through the door you generate enough power to make a cup of coffee" should read "Each time you pass through the door you generate enough power to make a cup of coffee, provided the water is already boiled and in close proximity to the coffee grounds."
Of course, boiling and transporting the water takes up the bulk of the energy required to make a cup of coffee. - Murdats, on 12/05/2008, -0/+6at a coffee place the water is usually kept continuously warm, to make your coffee, from you walking in the door saying I will have a coffee they just have to have maintained the heat and pumped the water.
- dubiousness, on 12/05/2008, -0/+6Actually, revolving doors are typically more energy efficient than traditional swinging doors and sliding doors. Because they never allow a direct interface between the outside and inside air, the volume exchanged is kept to a minimum, and so is heat transferred.
- hilanderiam, on 12/05/2008, -0/+6Just heating a cup of water 50K would require ~40kJ (1 cup = ~0.2kg).
In terms of potential energy that would be the same as lifting up 40 000kg one meter.
Or... it's a very tiny "cup of coffee". - mithrasinvictus, on 12/05/2008, -0/+6Maybe in Europe, but I found this: Murder rate (homicides per 100.000)
Amsterdam 7.7
Washington DC 69.2
Philadelphia 27.4
Dallas 24.8
Los Angeles 22.8
Chicago 20.5
Phoenix 19.1
Houston 18
New York City 16.8
link:http://www.independent.ie/national-news/dublin-mur ... - Murdats, on 12/05/2008, -1/+7that air is going to be lost anyway
I don't think the point is net gain, I think its reduced net loss. everything that is being done is being done anyway, you may as well try and get a little something from it.
the only downside is I imagine the door will be harder to push because its hooked up to a generator. - AFelsinger, on 12/04/2008, -0/+5every little bit counts i suppose
- solid12345, on 12/05/2008, -2/+7A fictitious currency created by...really who came up with that crap.
- xptoast, on 12/05/2008, -0/+5I have lolcat images on my computer to stave off the debt crisis.
- Grooblle, on 12/05/2008, -0/+4Not really.. Holland in orange:
http://upload.wikimedia.org/wikipedia/commons/6/69 ...
And the town Zeist is not in the area that counts as "Holland". - malanic, on 12/05/2008, -0/+4Here's the digg story;
http://digg.com/environment/Lamp_Lit_by_Gravity_La ... - inactive, on 12/05/2008, -0/+4Bad image!
- pebecker, on 12/05/2008, -1/+5Unless I'm doing the numbers wrong or reading the article wrong, there is NO WAY that rotating a revolving door once will produce enough energy to make 1 cup of coffee.
A simple napkin calculation, rounding everything, shows that to heat 0.1 gallons of water from 60F to 212F takes approximately 40 Watt-hours of energy. That's 40 watts for 1 hour. Let's say it takes 5 seconds for the door to go around, that'd mean you'd have to produce 28KW of power in that 5 seconds. Think you can produce 28,000 watts of power pushing on a door for 5 seconds? I don't.
Let's say it takes 10 whole seconds for that door to go around, that's still 14,000 watts. Sorry, something isn't right or my calculations are wrong.. - LiberalThinker, on 12/05/2008, -0/+3A lot of these people seemed to know a lot about this seeing as they all seem to be 'calling BS'.
Decide for yourselves ladies and gentlemen...go find out.
I do however agree that kids and revolving doors are a interesting potential solution... - enrq, on 12/05/2008, -1/+4you're doing it wrong...
- dubiousness, on 12/05/2008, -0/+3No, I don't suppose anybody steams coffee... I was being pretty generous with the door push of course, but you do have to go through twice. However, I can't imagine a cold tap in The Netherlands putting out 40C (104F) water. I think a base temperature of 15C to 25C would be more reasonable, perhaps even colder.
I suspect someone confused either W·h for kW·h or calories for Calories. If they were off by a factor of a thousand, the erroneously calculated energy requirement could be met by a reasonable 10 to 20 pound push. - AlJensen, on 12/05/2008, -0/+3That's Genius. I also like the idea of the powered street lights, by stepping on a kinetic powered sidewalk.But why stop there? how about a generator on my office chair? or on my toilet seat? my dresser, my closet, my car door, all of my cars wheels, in my shoes, on my microwave door, fridge door, hamster's wheel or on the back of a pimps hand?
- AnotherBrian, on 12/05/2008, -0/+3Gravia Lamp
http://dansdata.blogsome.com/2008/03/03/stop-press ... - sjmulder, on 12/05/2008, -0/+3Sure, with hageslag.
Hagelslag
Sommigen blijven droog en anderen voelen de pijn
Hageslag
Een geboren baby sterft nog voor de zonde
Hageslag
De schoolboeken zeggen dat het hier niet kan zijn
Hageslag
De gevangenissen zetten je toch wel aan het denken
… - Trigonometron, on 12/05/2008, -1/+4MEATSPIN
- Murdats, on 12/05/2008, -0/+3wow are you being overly nit picky
at the beginning of the day they heat the water up, just like they turn the lights on, if you want to break it down entirely to produce 1 cup of coffee you would have to consider the energy used to heat and keep heated the water, power the pump, grind the coffee, the mechanical energy of moving cups and pressing buttons, the transportation of the coffee, the mining, smelting, processing and manufacturing of all the metal, plastic and ceramic parts of the machine and cups, the cost of manufacturing of all transportation vehicles, the energy used to pick, package and grow the coffee, the cost of retrieving, cleaning, packaging and transporting the water, milk, sugar and chocolate and all the energy going into all of those.
but for the sake of a simplistic comparison lets ignore all of those and use something that people who aren't douchebags can comprehend. - mrtrik, on 12/05/2008, -0/+3Revolving doors do a much better job of keeping the air (warm or cold) in vs losing that air than traditional doors.
So they are reducing heating/cooling costs just by having a revolving door vs a traditional door, plus this generator idea.... kudos to them. Think about how many revolving doors exist in the world. If everyone had this... these guys (the generator manufacturer) could stumble on a gold mine. - emjaymj, on 12/05/2008, -2/+4Whoa, weights can be lifted without energy?! This is going to change physics as we know it o_O!
- SlechtValk, on 12/06/2008, -0/+2why only show homicide rate in US city's, why not worldwide...
http://en.wikipedia.org/wiki/List_of_countries_by_ ...
(you could see The Netherlands in the lightest shade of blue... in other words the lowest crime rate worldwide... OK it's a very rough scale) -
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