The basic idea here is actually a very old approach -- clocks have been powered this way for centuries. But it's very cool and refreshing to see a modern electrical spin on it.
GravityLight: Generate light with gravity
11–20 of 132 posts
Re: GravityLight: Generate light with gravity
#12This is wonderful. I plan to buy at least one for emergencies, and also to help make them cheaper for others.
A battery powered LED torch is far superior for emergencies. The only reason you'd really want to use this is if you really can't afford a solar-rechargable battery. (But for some reason can afford this, which I'd expect to be more expensive.)
Although that might be true, battery powered flashlights/torches suffer from the problem of leaky batteries. I've tried to use many flashlights that don't work, only to find the batteries have started to leak acid and ruined the flashlight. Sure, one should check the batteries every year or so, but who really does that? I'm not saying the gravitylight is a good replacement, just that battery powered flashlights do have some drawbacks.
Re: GravityLight: Generate light with gravity
#13Earlier quoted context omitted.
A battery powered LED torch is far superior for emergencies. The only reason you'd really want to use this is if you really can't afford a solar-rechargable battery. (But for some reason can afford this, which I'd expect to be more expensive.)
Although that might be true, battery powered flashlights/torches suffer from the problem of leaky batteries. I've tried to use many flashlights that don't work, only to find the batteries have started to leak acid and ruined the flashlight. Sure, one should check the batteries every year or so, but who really does that? I'm not saying the gravitylight is a good replacement, just that battery powered flashlights do ha…
This is what lithium primaries are for; they don't leak.
Re: GravityLight: Generate light with gravity
#14You need to lift a 10KG weight about 2 kilometres to get a teaspoon of kerosene's energy, so it's not a great replacement on that front, and having 10KG weights dangling around at variable points between ceiling and floor sounds if anything even more of a liability than a lamp with a naked flame, which does at least stay where its put. Sorry to be negative but it's difficult to conceive of a realistic scenario where…
The amount of energy is not directly comparable if the efficiency of its use is very different. A kerosene lamp is multiple orders of magnitude less efficient than decent LEDs, so while you might have to lift 2KM to get the same energy, you'd have to lift much, much less to get the same amount of lumen-hours.
A kerosene lamp has an efficiency of 0.1-1 lumens/watt, while a white LED has anything around 80-100 lumens/watt.
Re: GravityLight: Generate light with gravity
#15You need to lift a 10KG weight about 2 kilometres to get a teaspoon of kerosene's energy, so it's not a great replacement on that front, and having 10KG weights dangling around at variable points between ceiling and floor sounds if anything even more of a liability than a lamp with a naked flame, which does at least stay where its put. Sorry to be negative but it's difficult to conceive of a realistic scenario where…
Regarding the energy of lifting a 10KG weight 2 KM high is not a 1:1 comparison with the tech here. It's using an LED which much more efficient than a Kerosene powered flame, since most of the energy in the flame is spent in infrared.
Re: GravityLight: Generate light with gravity
#16You need to lift a 10KG weight about 2 kilometres to get a teaspoon of kerosene's energy, so it's not a great replacement on that front, and having 10KG weights dangling around at variable points between ceiling and floor sounds if anything even more of a liability than a lamp with a naked flame, which does at least stay where its put. Sorry to be negative but it's difficult to conceive of a realistic scenario where…
> You need to lift a 10KG weight about 2 kilometres to get a teaspoon of kerosene's energy, so it's not a great replacement on that front
This says nothing of light output. If you want light, and most of kerosene's output is heat, your energy calculation is not helpful.
> and having 10KG weights dangling around at variable points between ceiling and floor sounds if anything even more of a liability than a lamp with a naked flame
This seems like an incredibly contrived "problem". What's the liability? Somebody may bump into a somewhat heavy object that is moving downwards at a barely perceptible clip? Somebody may tweak their back lifting the weight? That seems lower risk than my housing burning down with me in it.
Re: GravityLight: Generate light with gravity
#17You need to lift a 10KG weight about 2 kilometres to get a teaspoon of kerosene's energy, so it's not a great replacement on that front, and having 10KG weights dangling around at variable points between ceiling and floor sounds if anything even more of a liability than a lamp with a naked flame, which does at least stay where its put. Sorry to be negative but it's difficult to conceive of a realistic scenario where…
How much of that energy of the kerosene is converted to visible light?
This is some LEDs, a weight, some gears and an alternator. Is a solar panel and a battery going to come anywhere close in price?
Re: GravityLight: Generate light with gravity
#18The basic idea here is actually a very old approach -- clocks have been powered this way for centuries. But it's very cool and refreshing to see a modern electrical spin on it.
Might be fun to make an electric clock that uses gravity, go full circle.
Re: GravityLight: Generate light with gravity
#19Earlier quoted context omitted.
Although that might be true, battery powered flashlights/torches suffer from the problem of leaky batteries. I've tried to use many flashlights that don't work, only to find the batteries have started to leak acid and ruined the flashlight. Sure, one should check the batteries every year or so, but who really does that? I'm not saying the gravitylight is a good replacement, just that battery powered flashlights do ha…
This is what lithium primaries are for; they don't leak.
And before anyone jumps in and says "lithium batteries self discharge!" Yes, yes they do. But it's really, really small. It discharges quickly initially, but then tapers off to about 1% per month.
Re: GravityLight: Generate light with gravity
#20This is wonderful. I plan to buy at least one for emergencies, and also to help make them cheaper for others.
A battery powered LED torch is far superior for emergencies. The only reason you'd really want to use this is if you really can't afford a solar-rechargable battery. (But for some reason can afford this, which I'd expect to be more expensive.)
> A battery powered LED torch is far superior for emergencies. The only reason you'd really want to use this is if you really can't afford a solar-rechargable battery.
Rechargeable batteries can be reused, but still need to be replaced; this may prove lower maintenance, which means once you can get it, you are more secure with it with a less secure distribution system. In many of the places where people are without electricity in the world, that's potentially a significant benefit.
(Also, solar recharging in places that experience long periods of darkness, e.g., the arctic, may not be an ideal solution. There aren't any places that experience extended periods without gravity, at least not on Earth.)