Well, the weight is stated as 50 pounds in one of the diagrams…

I don’t see anything wrong with m’s math. Looks like you will need a crane to start your lamp.

The claims are outright fraud, and would only work if 2 + 2 = 400…

Here’s the whole math:

0lbs == 22.6 kg
4 ft == 1.21 m

Potential Energy = mgh = 22.6 kg * 1.21 m * 9.8 m/s^2 ~= 270 J

Power = energy/time = 270 / (60 minutes/hour * 60 seconds/minute * 4 hours) = .019 Watts.

Assume 100% conversion of that power into visible light (a PERFECT lamp) is 683 lumens/watt. So this would be 12 Lumens of output.

A typical 40W bulb outputs 500 lumens!

So the design is a FRAUD, it CAN’T WORK! In order to get the 500 lumens of output, with theoretically perfect efficiency, it either needs 40x the weight (so a TON of weight, literally), 40x the drop (so a 160 foot fall), or can only operate for 6 minutes, and this would be with a perfectly, 100% efficient conversion of the potential energy into power and the power into illumination.

Its not a green design, its outright snake-oil, and if it worked as advertised it would violate the laws of physics.

Frequently with LED lights, you don’t actually have the LED on all the time. Very short but high frequency pulses (i.e. low duty cycle).

Above a certain threshold you can’t tell the light is flashing, but it is.

Additionally, you don’t have to be able to provide the instantaneous power on each cycle – you have the time between cycles to accumulate it. Think of a camera flash and how it charges. Now speed it up.

I have not worked out the numbers for this assumption, but it may at least come closer to working, as opposed to being off by a factor of 1000 in the constant-power case.

It’s great for hi-gear-ratio reduction and can be built on to the end of a motor, so it’s been used in robotic arms that need to be thin & have high-torque.

I liked your earlier comment, too – As a design presentation it’s really good. But, the goal was to “come up with new and innovative solutions to address the issues of energy, carbon footprint, health and toxicity, new materials, product lifecycle, and social development.”… so, with a 200 year life, they must have been going for product lifecycle & not energy conservation. Of course, most lamps (not bulbs) would last 200 years, too.

I’m disappointed that Mark’s original post didn’t come with a heavy dose of skepticism– instead, it was presented as “this is neat!” The link leads to “Pure Energy Systems”– they don’t seem to distinguish between real and fictional gadgets.

Very steam punk.

Drag out and dust off those old family heirlooms – hack ‘em with small generators and pimp ‘em out with LED’s. Real grandfather clocks that illuminate. Jam a bright blue bulb up the arse of that little annoying bird that pops out al the time. Make a sensuous glow come from your great grannie’s old mantel clock.

Brilliant!

To calculate the needed weight:
700 lumens @ 90 lm/watt (an efficient LED) = 7.78 watts.
7.78 watts * 4 hours = 31.1 Watt-Hour = 112,000 Joules
Potential energy of 4 feet high weight = mgh = mass * 9.8 m/s^2 * 1.22 meters
112,000 Joules = mass * 9.8 m/s^2 * 1.22 meters
==> mass = 9367 kg = 20650 pounds = 10 tons.

It’s still a beautiful light & a cool design. The VT Architecture is awesome (I got an EE degree from there).

In any case, sweet. If it works, I want one.