Gravia ‘Gravity Lamp’ lasts 200 years, doesn’t have power cord
A Greener Gadget Award has been given to Clay Moulton, a Virginia Tech student, for his floor lamp powered entirely by gravity.
The Gravia, as it is called, has 10 LEDs and is powered by a weight which is manually raised once a day and slowly falls to the bottom as the day progresses. There is no power cord in sight. The entire column, measuring just over 4 feet high, gets a soft, diffuse glow as a result.
The best part? Moulton estimates that the Gravia can last about 200 years with daily use, and that its lifespan is only limited by the LEDs which will go out by then.
This is definitely one of the greenest gadgets around. Who doesn’t want a device that will power itself as long as you live? Although probably not the brightest lamp around, at a reasonable price the Gravia would make a welcome addition to many homes.
Tags: gravia, green, led, light
February 19th, 2008 at 11:11 am
it looks as though the world is finally trying to invent rather than re-invent. this is by far one of the most innovative things of this year (i know it’s only feb).
February 19th, 2008 at 4:37 pm
Wow, where do I signup? That thing is really cool, but I don’t know, I’m pretty lazy. Do I really have to manually raise the weight everyday? Sigh. Maybe when this thing makes a clapper version.
February 20th, 2008 at 9:39 am
This thing doesn’t work. They claim 4 hours, but you’d be lucky to get 4 minutes.
This thing has a 23kg weight, falling 4ft, which gives an output of 270J, assuming 100% efficiency (!)
270J is 1W for just over 4 minutes. One watt for 600 lumens is also really, really generous. The best are in the region of 150 lumens/watt.
February 20th, 2008 at 10:24 am
Ian, I agree with your calculations however maybe when you lift the weights the ‘rotor’ is still engaged and as a result you are doing more than using the potential energy of gravity. As you lift the weights, it turns the rotor and stores that energy as well?
Just a thought. See the design at
http://www.core77.com/competitions/greenergadgets/projects/4306/greener_gadgets_03.jpg
February 20th, 2008 at 4:46 pm
That kid doesn’t have to work anymore.
February 21st, 2008 at 12:01 am
Pay attention to Ian Calvert’s post above. His calculations are *very* generous and give an upper bound on output at 4 minutes.
Kevin: even if it engaged the motor while life the weights (which is not in the “design”), note that then *we* still have to provide that energy (and over the work required to lift the weight in the first place!) Thus, if the rotor applied an extra 23 kg of resistance to lifting, assuming 100% efficiency and a storage device (the design does have one) , you could double the life of the unit (to <8 minutes). Now your lifting ~100 pounds!
If you want to get that extra 54 minutes from these *very* generous calculations, the rotor would have to provide resistance of somewhere over 300kg, just a little beyond human capabilities.
In short, unfortunately some things just are too good to be true. Fortunately, we do still have stuff like human-powered flashlights - we just have to do actual *work* for that energy!
February 21st, 2008 at 10:29 am
I can’t believe people fell for this bullshit. This little sociopath won an award, for chrissakes.
As if we lived in a world where we could get most of the power we need by occasionally running around and lifting shit off the ground.