The amazing gravity-powered lamp design that won a 2nd-place Greener Gadgets Conference competition award for Virginia Tech grad Clay Moulton last month is too good to be true. Literally.
This is how Moulton’s Gravia Lamp is supposed to work: Weights totalling 10 lbs. move slowly down a narrow brass slide, activating a rotor. The rotor powers ten LED lights in the 4-ft.-high acrylic column, generating about as much light as a 40-watt bulb for up to four hours. The weights would have to be moved to the top of the slide at least once a day, but that’s a small price to pay for a cordless lamp that could last for an estimated 200 years.
Though public response was enthusiastic, Moulton likely would have hit a snag when he applied for a patent: As pointed out by Colin Watters on the Green Building forum, even with maximum efficiency (100%) LED lights, which don’t exist, the lamp would have to weigh 1.4 metric tons to function as intended. Like so-called free energy devices, the theoretical lamp simply generates more energy than what is being put into it.
Faced with these facts, Moulton admitted that his design was purely theoretical.