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GravityLight: Generate light with gravity

gravitylight.org

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Re: GravityLight: Generate light with gravity

#81

Post by aaron695 »

ris wrote: post #58

I implore people to support something far more practical like http://www.solar-aid.org/ than this. Solar lights are many times more thermodynamically efficient, cheaper to make, smaller and much more robust (no moving parts!). This "lifting weights" thing is a silly gimmick. A lifted weight stores a miniscule amount of energy compared to a battery that's been charged by the sun.

Coal and kerosene are cheap.

We need to stop dicking around with idealistic ideas involving electronics and design more efficient and safer uses of these existing cheap fuels for lighting and more importantly cooking and phone charging.

They are being used because they work for people in these situations.

http://www.gatesnotes.com/Energy/Two-Videos-Illuminate-Energ...

Re: GravityLight: Generate light with gravity

#82

Post by metasean »

mabbo wrote: post #8

There's a lot of reasons why this is cool, but I'm skeptical about it's aims to get rid of kerosene lamps. Kerosene lamps are made with garbage. They can be replaced in minutes if there's a problem. Fuel costs are high, yes, but capital costs and maintenance are low. Those matter. To really make this a long term win, you need to make it indestructible and easy to repair with on-hand parts. I hope they can do that.

It looks like they are trying to make them in a locally sustainable manner...

>We're doing this in our approach to distributing GravityLight

>We are partnering with local networks of people earning a living by selling products such as GravityLight, rather than disrupting local markets and jobs with free giveaways.

>We're doing this in our manufacturing strategy

>We aim to create jobs and skills in the regions where GravityLight will be sold, firstly by establishing an assembly line in Kenya.

from http://gravitylight.org/our-approach-3/

---

And it looks like they've already run into robustness issues, but they weren't due to cheap plastic components, and it looks like they've modified the system to deal with them...

>GL01 had a protection mechanism that clearly indicated an overload with a red light, and helped reduce damage to the gear teeth by allowing it to run more swiftly, but this did not make it indestructible. An entirely novel way of protecting the system has been designed for GL02. It will allow an overloaded bag to descend to the ground in a safe and controlled manner, repeatedly.

>GL02 suspends the bag from a pulley, which reduces the strain on the cord and the gearing. This also decreases the loading on the drive system and permits a smaller gearbox ratio, which helps to improve efficiency.

from http://gravitylight.org/coming-soon-gl02/

Re: GravityLight: Generate light with gravity

#83

Post by pbhjpbhj »

effie wrote: post #79
leanthonyrn wrote: post #34

Earlier quoted context omitted.

Can't you suspend a bed wired to one of these to the ceiling? At night before you go to sleep climb the stairs and get into the potential energy elevated bed. Then in the morning, after the bed descends, you have enough reading light energy stored for the next night.

How do you lift the suspended bed back up again?

Unhook the four corners from the system, raise the "hooks" and have 3 or 4 associates help you lift the bed on to the hooks?

Re: GravityLight: Generate light with gravity

#84

Post by nwmcsween »

mabbo wrote: post #8

There's a lot of reasons why this is cool, but I'm skeptical about it's aims to get rid of kerosene lamps. Kerosene lamps are made with garbage. They can be replaced in minutes if there's a problem. Fuel costs are high, yes, but capital costs and maintenance are low. Those matter. To really make this a long term win, you need to make it indestructible and easy to repair with on-hand parts. I hope they can do that.

Yeah this seems to be a big issue just by looking at it and makes me wonder why they didn't use everyday parts like a chain or a sprocket off a bike.

Also I wonder if you could just do all this with a refitting of a rachet lever hoist or something similar.

Re: GravityLight: Generate light with gravity

#86

Post by aidenn0 »

fla wrote: post #65
aidenn0 wrote: post #55

Earlier quoted context omitted.

My automatic watch contains an electronic circuit, so I'm not sure what your point is.

Interesting. What is the circuit for ? Are you sure it's not powered by a standard watch battery ?

Yes, it is a quartz movement with a capacitor that is charged by a mechanism similar to a mechanical auto-winding watch.

https://en.wikipedia.org/wiki/Automatic_watch#Automatic_quar...

Re: GravityLight: Generate light with gravity

#88

Post by imaginenore »

CyberDildonics wrote: post #80
Gravityloss wrote: post #61

Earlier quoted context omitted.

1 watt of led light would require 1 Newton at 1 meters per second. Assuming 100 kg is the highest practicable mass, so that's 1000 Newtons -> 1/1000 m/s for each watt. Assuming a height of 2 meters, you could operate a very dim 2 watt led light for 17 minutes. I think that's not practical.

You can use it to read and it is free.

It's not free. It's a very inefficient way of converting food to human energy to humans lifting weights that in turn power the lights.

If this is targeted at very poor people, food isn't cheap for them.

Re: GravityLight: Generate light with gravity

#89

Post by jameshart »

Gravityloss wrote: post #61
pavel_lishin wrote: post #28

Earlier quoted context omitted.

But this isn't for charging a phone; it's for having light, right now.

1 watt of led light would require 1 Newton at 1 meters per second. Assuming 100 kg is the highest practicable mass, so that's 1000 Newtons -> 1/1000 m/s for each watt. Assuming a height of 2 meters, you could operate a very dim 2 watt led light for 17 minutes. I think that's not practical.

Or, using the numbers provided for this actual product which exists, rather than a spherical LED on a frictionless plane, we raise a 12kg mass 1.8m and get a 0.1W LED light for 20 minutes. Do you think THAT's practical?

Re: GravityLight: Generate light with gravity

#90

Post by ricardobeat »

brannon wrote: post #87

A 12kg weight hanging 6 feet in the air seems a little dangerous to me. Definitely less dangerous than a kerosene lamp, but I'd be worried about poorly attached weights falling if someone bumps their head on it.

Do you own a TV? It's certainly way more dangerous than that.
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