Gravity Lamp Grabs Green Prize 596
eldavojohn writes "A lamp powered by gravity has won the second prize at the Greener Gadgets Conference in NYC. From the article, "The light output will be 600-800 lumens — roughly equal to a 40-watt incandescent bulb over a period of four hours. To "turn on" the lamp, the user moves weights from the bottom to the top of the lamp. An hour glass-like mechanism is turned over and the weights are placed in the mass sled near the top of the lamp. The sled begins its gentle glide back down and, within a few seconds, the LEDs come on and light the lamp ... Moulton estimates that Gravia's mechanisms will last more than 200 years, if used eight hours a day, 365 days a year." The article contains links to the patents and the designer/inventor Clay Moulton's site." I think my laptop would require a slightly larger weight to pull this off.
Looks cool... (Score:2, Funny)
Re:Looks cool... (Score:5, Funny)
This is slashdot, we have articles here, not thinly disguised advertisements.
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Next thing you know... (Score:4, Funny)
When I was a little kid I built a gravity go cart (Score:5, Funny)
I guess I was ahead of my time.
All I remember was.. the brakes didn't work, and I felt pain for 2 weeks.
Re:When I was a little kid I built a gravity go ca (Score:5, Funny)
Re:Looks cool... (Score:5, Interesting)
However, one thing concerns me. The weights are moved up to the top by human power, which is fine, but according to the picture on the designer's website, the weights are 5 10 pound weights in each lamp, so either I'm having to lift 10 pounds 5 times every time I want to light the lamp, or I'm lifting 50 pounds. Perhaps he could incorporate some sort of foot pedal mechanism or something to more easily lift the weights. If he could figure out how to do that, and also maybe improve the efficiency a little more to get more than the 40-watt equivalent it gets now, I could see this becoming a solid replacement for traditional lamps.
Re:Looks cool... (Score:5, Funny)
I can't really see why a small electric motor couldn't be incorporated into the design to do this, surely it would be much more convenient?
Re:Looks cool... (Score:4, Funny)
That way, you could still run the light in a power failure by running the small ICE.
Hey, you could make the engine a little bigger and add some outlets so you could power other lamps.
(The outside of my tooth is delicious.)
In the town of Bedrock... (Score:5, Funny)
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You think that people will be motivated by the desire to read? Make a TV powered by this concept, however...
Re:In the town of Bedrock... (Score:5, Funny)
Re:Looks cool... (Score:4, Funny)
Re:Looks cool... (Score:4, Insightful)
Why not use a spring? (Score:3, Interesting)
Re:Why not use a spring? (Score:4, Informative)
I think part of the beauty of the mechanism is that it's really robust and long-lasting.
Just thinking about how you could build such a thing, I bet you could make a machine that had multiple ways of recharging/resetting it. My thought would be to have a lightweight 'sled' with a heavy removable weight on it. When the heavy weight is removed from the sled, a very small counterweight pulls it back up to the top of its track, so you can place the heavy weight back on. That's one way of resetting it, and the easiest provided you could pick up and lift the weight at once. The alternative would be to put a small crank on the sled's counterweight wire, which would allow you to slowly crank up the sled, with the counterweight on it. You'd end up doing the same amount of work but with a much smaller amount of force, due to the mechanical advantage of the crank.
That arrangement completely avoids using springs (it would only use counterweights) and would probably last a long time. I'm not sure whether it would be long enough to build some sort of 'Clock of the Long Now'-type device, but it would probably last a few human generations.
Re:Why not use a spring? (Score:4, Insightful)
As to the people whining about how it's too much work to move the weights... check your waistlines. 'Nuf said!!
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Uh, I'm pretty sure they are still used most of the time even with automatic doors. Those chincy little motors couldn't lift the full weight of a wooden garage door, nor could their mountings handle it most of the time. The spring is still there, and is still doing most of the work. Certainly at least when the sprin
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Which just goes to show how little you should trust your intuition or feelings when it comes to true environmentalism.
We live on a 13,170,856,500,000,000,000,000,000 pound rock. Are you sure that 50 pounds of mass is going to break Gaia?
50 pounds of something in particular could be an environmental problem. 50 pounds of mercury would be horrible. But just "50 pounds" is nothing. Personally, I'd love to have thi
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Re:Looks cool... (Score:4, Funny)
Think of it in terms of your health/fitness and gym membership fees you save.
Re:Looks cool... (Score:4, Insightful)
Unless you are weakened by some medical condition lifting 10 pounds, 4 feet, 5 times in a row, every four waking hours isn't enough of a demand to be an issue. On the contrary I think this regular weight bearing movement might be a very good thing for the elderly or physically frail. [familydoctor.org]This could be viewed as an in-home several-times-a-day physical therapy light. Maybe a moveable stop, which could allow for the weight to start higher off the floor, but would need to be rest more often would be good addition for those with bad backs or knees that can't reach low to the ground. But to force people to get off the couch every two to four hours and move a few ten pound weights can really only be a benefit for the majority of the western world.
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Then you just lay it on the floor, and stand it back up again on the opposite end.
I guess maybe the rotors can only gear one way or something.
Re:Looks cool... (Score:5, Interesting)
Set the stand on the floor, it has an arm that goes up to 50% of the height of the lamp and attaches to the back of the lamp. The lamp would be supported by the stand and wouldn't actually touch the floor. When the weight reaches the bottom, simply flip the lamp over by applying force to the upper portion. You could add in little catch or ratchet points so it would be easy to do.
Re:Looks cool... (Score:5, Funny)
Wet noodle? (Score:4, Funny)
Re:Looks cool... (Score:4, Funny)
Give me your lunch money.
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Re:Looks cool... (Score:4, Funny)
Re:Looks cool... (Score:4, Funny)
Re:Looks cool... (Score:5, Interesting)
Re:Looks cool... (Score:5, Informative)
because it cant be made. You have a better chance at making cold fusion work or a perpetual motion machine than making this lamp do what was claimed.
first, there is no way for them to make enough energy even assuming 100% conversion to generate the electricity needed to power even 1 led for enough light to match that of a book light, many others here have covered this fact already..
Secondly the designer made HUGE mistakes in assumption is is a fact being missed by everyone else here debunking it.. Led's when rated in lumens are rated in their very narrow beam pattern, when you fire it into a lens/reflector to disperse the light to get an area lighting effect that his lamp is going for the lumens drop logarithmically. to go from the 15Deg beam pattern the LED's lumen output is measured at to a 270 degree pattern you will lose about 80% of the lumen output level.
So to get The claimed output, the device needs to generate a SHITLOAD more power, or increase the weight to be near 900 pounds or only operate for a few seconds at a time.
In other words, it does not work, cant work, and will never work. I think the guy is waiting for the laws of physics to be broken for his lamp to work.
I have been working with a company that designs LED lighting systems and most everyone get's confused because ratings on LED's are all over the road and not measured the same way as other lamp technologies.
This lamp if it used CFL lamps would have a far better chance at makign the claimed Lumen output than with LED's led's are still far-far less efficient than CFL lamps when it comes to area light output in beam widths wider than 20 degrees.
It can't possibly work either (Score:5, Informative)
The red led on the front of your modem requires around this amount so the glow will be feable. To get the equivalent of a filament 40W bulb requires around 10W so the system is only around a factor of 1000 out.
Re:It can't possibly work either (Score:4, Interesting)
White LEDS are currently ~65 lm/W and will possibly soon be 150 lm/W http://en.wikipedia.org/wiki/Light-emitting_diode#Operational_parameters_and_efficiency [wikipedia.org] so there is approx factor of 10 improved efficiency, so if the lamp can achieve 4W output he can match the 40W incandescent output. Even so this would require 57600J over 4 hours, which from a potential energy release from 1m would required a weight of 5000kg, so I think he fucked up his calculations or got a bit carried away.
Still, don't let science get in the way of art!
Re:It can't possibly work either (Score:5, Informative)
The red led on the front of your modem requires around this amount so the glow will be feable. To get the equivalent of a filament 40W bulb requires around 10W so the system is only around a factor of 1000 out.
Your conclusion is right, but your figures are a bit out. The drop is 58" according to the plan [core77.com]. This gives about 0.022W at 100% efficiency.
For reference, the highest efficiency LEDs that I know of get 131 lumens per watt. If we're generous and allow them 150 lumens/watt, they still need 4W of power. This would require a drop of 255 metres using the 50lbs of weights he claims. Since we can't really go above 1.5m high, we'll need almost 4 tonnes of weights.
A shame really, I'd have rather liked one.
Re:It can't possibly work either (Score:5, Insightful)
Meanwhile they're talking about how it would last two hundred years. Right. That's what they spent thier time with, trying to find a way to convince people how incredibly green this thing is.
I hate this sort of environmentalism that has absolutely no regard for reality. This one has no regard for basic conservation of energy, they might as well have said we can solve the energy problem with perpetual motion.
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I think it was Popular Science (maybe Popular Mechanics) that had a safety product design contest after 9/11. One of the winning entries was a device the size of a tube of lipstick that was supposed to contain an absurd amount of compressed oxygen - something like 30 min
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Re:It can't possibly work either (Score:5, Informative)
And exactly how does having a screw generate more energy?
The path the weight takes to the ground is irrelevant.
An object weighing X lifted to a height of Y meters generates has a certain amount of potential energy, regardless of the path taken to the ground.
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OK, let's go back to physics 101. The device has stored a certain amount of potential energy when the weight is on the top, and a lower potential when on the ground. That's all there is, that's all the energy you can transform into light. Nothing can change that. The only effect (besides added friction) of making it spin around is that you stretch the time in which you make use of the energy. Result: less light, but over a longer time period.
Not that it would even be a bright light if the weight would
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Re:You are way, way off (Score:4, Insightful)
Watt is newton per second, not newton per minute. You forgot a divide by 60.
Re:It can't possibly work either (Score:5, Funny)
One Design Improvement (Score:3, Interesting)
Just a thought.
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Home Gym.. (Score:2)
Re:Home Gym.. (Score:5, Insightful)
Never
Humans can not produce large amounts of sustained output power, even when exercising. A "healthy human" can probably push out 300W for about 20 minutes [ohiou.edu] before they collapse from exhaustion. Even if you can convert all of that to electricity and store it for later use at something like 50% efficiency (which would be staggeringly high), you're only talking about 0.05kWh of usable energy. You could do much better if you were willing to exercise at much lower intensity for much much longer periods of time (but who would do that just to light a minuscule handful of light bulbs). But you're really not going to ever get usable amounts of power out of your daily exercise routine.
Alas (Score:4, Funny)
Re:Alas (Score:4, Insightful)
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that's 4 reps to get the weights that high if attached to a ratcheting system. properly constructe
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But you're really not going to ever get usable amounts of power out of your daily exercise routine.
The real issue is that so much power is wasted. A lot of energy is just dissipated for no reason around your home. That energy could be harnessed somewhat inefficiently but still cheaply and if it were done over time and as a matter of course the actual cost would be minimal. Of course, so would the benefits, but we all know such things add up.
I've heard about several households where a crap TV was hooked up to a bicycle-powered generator. Oh sure, the TV probably dies an early death due to brownouts, bu
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Total Gym. (Score:3, Funny)
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Layne
What's next for gravity power? (Score:5, Funny)
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A patent? (Score:3, Insightful)
Re:A patent? (Score:5, Funny)
One tells time, the other emits light. I thought that was fairly obvious.
Re:A patent? (Score:5, Funny)
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bwahaha. (Score:5, Funny)
Re:bwahaha. (Score:5, Funny)
But who is going to control (Score:5, Funny)
Will it still be cool to light up your lamp with gravity, when there's no gravity left and people are spinning right off the planet into outerspace? I guess it will eliminate the greenhouse gas issue by allowing the atmosphere to disappear when there's no more gravity left - but unfortunately it will also not allow people to live (the ones that are still on the planet after the other ones spun off into space as noted earlier)
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Peak Gravity (Score:5, Funny)
Way ahead of you buddy (Score:5, Funny)
Re:Peak Gravity (Score:5, Funny)
One guarantee: it's all downhill from there.
Bending Space-Time Lights the Way (Score:5, Insightful)
LED technology (Score:3, Interesting)
Since this particular lamp emits too much blue, I would wager that it uses a blue indium-gallium-nitride LED.
Increasing the phosphorous coating would make the resulting color more yellow and thus negate any need to wait 15 years.
The most commonly used phosphorous emits in the 580nm range (yellow), while the blue diode itself emits light at around 470nm (blue, surprisingly).
I total misread that (Score:3, Funny)
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Wouldn't it be more accurate... (Score:3, Insightful)
I guess "Potentia" isn't as marketable a name, though.
And it runs for four hours, too. (Score:3, Informative)
Four hours is an awesome run-time for such a device.
I lived in a house once where the land lord had a wind-up radio. It was great in every respect other than its run time; every fifteen minutes or so you had to crank it up again, which made it annoying to use.
-Fl
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The maths just don't check out, however. There is no way to produce that much light for four hours with anything less than a ton or so of weight.
Physics for designers (Score:5, Informative)
There's 50lbs of weight that fall about 4ft, if I'm reading the diagrams right. That's 200 ft-lbs. Which comes out to... hmm... 0.075 watt-hours. Over 4 hours that means 0.019 watts continuous power. From memory really good blue LEDs are around 200 lumens/watt so
To get ~700 lumen light at 200 lumen/watt would require 3.5 watts of power, over 4 hours is 14 watt-hours or 3700 ft-lbs. Over 4ft of fall that amounts to 925 lbs. My goodness, that is a group effort.
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He might not, but here's my work (Score:4, Insightful)
He might not, but from what I gather, it's something like this:
PGE = m*g*h (potential gravitational energy in joules = mass * gravity * height)
50 lbs = 22.7 kg
PGE = 22.7 * 9.81 * 1.5 (I'm assuming a generous height of about 1.5 meters here, based on his diagram which gives 58" as the height)
PGE = about 334 joules
A joules is one watt-second, so 334 joules means 334 watts for one second, or 1 watt for 334 seconds.
According to Wikipedia, "The highest efficiency high-power white LED is claimed by Philips Lumileds Lighting Co. with a luminous efficacy of 115 lm/W (350 mA)." The claims is that this light can produce 600-800 lumens. If we take the lower number, 600, that breaks down to about 5 1-watt super-efficient LEDs to produce about 600 lumens.
So that's 5 watts per second, which with energy of 334 joules yields about 66 seconds of output. A far cry from 14,400 seconds (four hours).
Feel free to correct my math, it's been years since I've taken physics.
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Next step ... (Score:3, Interesting)
Re:Next step ... (Score:4, Funny)
Hmmm. What else falls around the house? (Score:5, Interesting)
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Thermal instead of potential energy recovery (Score:3, Informative)
http://www.eere.energy.gov/consumer/your_home/water_heating/index.cfm/mytopic=13040 [energy.gov]
http://www.gfxstar.ca/specifications.htm [gfxstar.ca]
As pointed out by some other posters, kinetic or potential energy recovery might lead to the nasty problem of clogged pipes, but thermal energy recovery doesn't have that problem.
Quality light is not like making coffee (Score:3, Funny)
Waste of time and money (Score:4, Insightful)
What about the FIRST prize winner... (Score:3, Interesting)
The first prize winner seems MUCH more interesting: An open-source design for an energy meter.
See here [core77.com]
Basically, he's gonna provide the design specs to build your own kill-a-watt [p3international.com]
So, it's:
And no interest whatsoever on Slashdot? WTF?
Small Correction (Score:4, Interesting)
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That's not how the electricity is being generated, rather it is coming from a rotor system.
There would be no functional difference between one 50 pound weight and 5 10 pounds weight, other than in resetting the system.
Re:green? I don't think that word means what you.. (Score:3, Insightful)
Ranting for no good cause. That's EXACTLY where it is aimed at, anyway. May I also point out that lifting those weights is not going to produce signficant enegy usage that someone is going to have to change their diet in the richer parts of the world. Don't forget that one of the biggest problems in the wealthy world is OVER eating not undereating!
Re:Doesn't check out. (Score:5, Informative)
Given that LEDs emit about 100 lumens/watt, that's say, 6 watts, * 4 hours = 86,400 joules They claim it's about 2m high.
Plugging those two values into the gravitational potential energy calculator at http://hyperphysics.phy-astr.gsu.edu/Hbase/gpot.html [gsu.edu] gives a weight of about 5000kg, slightly above the claimed 22kg...
Re:These numbers look worng (Score:3, Informative)
I'm replying to my own email. Sorry!
550 lbs over an hour will yield the numbers I posted. 55 LBS will yield 1/10 of the above.
He doesn't have 10.34 watts. He has (50/550)/3600 = 2.5253E-5 HP * 745 = 0.019 watts.
This won't provide much light.
550 lbs dropping 20 feet in 1 hour is (550/550)*20/3600*745 = 4 watts for an hour.
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Re:!perpetual motion machine (Score:4, Informative)
Force x Distance/Time=W
22.6Kg x 1.47m x (9.8m/s/s)/14400s =
A brushless motor can operate at up to 90% efficiency, but the friction in the system will reduce the efficience a lot. We'll just say it runs at 60% efficiency. That's just 13.5mW. You need five of these to power an LED under current configuration. They want 600-800 lumens. So we'll lowball the figure with 600. Each LED can do about 80 lumens.
600/80=7.5, so 8 LEDs. That's 400mW of power for the system, or 30 generators.
Either you need 30 generators, a 680Kg weight, a 44.1m tall light (falling 30x's faster), OR a planet with 30x's the gravity. Your call.
Re:!perpetual motion machine (Score:4, Informative)
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I think you have a parse error:
The design goal of Gravia is to provide light in a room (600-800 lumens — roughly equal to one 40 watt incandescent lightbulb), over a period of 4 hours, using people to generate power.
Note the parentheses. It really does say the goal is to light a room over a period of 4 hours.
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