I definitely watched the video. This is really nothing more than an awesome night light. That's how effective a single lower power LED is. It's hard to do anything by such little light, especially one that will be hung across the room.
said by aurgathor:
When you have a choice between this and a lamp that runs on petrol (roughly the same light output), or no light at all, I think the choice is pretty clear. Anything solar powered will normally require batteries -- they are expensive and wear out, especially in less than ideal operating conditions.
Maybe, maybe not. This light won't be bright enough to light up a room. It won't be bright enough to read by unless you stand up next to it. Don't be deceived by the video and pictures. This is not a bright light. Kerosene lamps are brighter and more portable. Kerosene can also be used for cooking. Really, the gravity light is an attempt to solve a problem without taking into consideration what is actually required to solve the problem. Simply making a light that costs nothing to run won't solve the problem. It has already been done.
The battery problems of solar lights were solved some time ago through the use of super capacitors. Although the company making the lights appears to have gone bankrupt. There wasn't enough demand for their lights, in part due to the price. NiMH batteries can be purchased for under $1 and last years.