That's one of those ideas that is stunningly simple and makes you wonder how you didn't think of it first.
An ingenious gravity-powered light source has reached its first funding goal in four days. Co-invented by industrial designer Martin Riddiford - who crafted Psion's hardware - the cheap kit allows an LED to be run for 30 minutes from a three-second pull on a rope. Gravity does the rest. The GravityLight was devised with …
Agreed, great implementation of a simple idea, but it's not unique. I remember having a pull-down camping light in the Seventies that worked off a similar principle - it hung from a hook on the end of a cord that was coiled around a clockwork mechanism inside the body, you pulled down against a clockwork spring, and whilst the unit wound itself back up the cord it would power an ordinary torch bulb in the bottom of the body for about three or four minutes. Very useful for those quick tasks that you didn't want to expend torch batteries on. LED tech makes it much more efficient but it seems to be the same principle.
This idea, or other like it, have been thought of many times before. It's simply that t wasn't feasible with energy slurpers liek incandescents, whereas the new high efficiency LEDs make this particular design practical.
And funding, of course.. It used to be that you needed to trawl for funding for ages to get anywhere, with all the risk of your design being corrupted or usurped by some smart-alec. Direct crowdfunding shortens those lines towards funding as well, so you can actually get from idea to deployment a hell of a lot quicker.
"This idea has been thought of many times before...in fact, I believe Apple are seeking a cease and desist as it breaches a patent of theirs."
Your half-witticism has also been thought of many times before, and some of those thinkers were dim enough to think that it was clever enough to actually post.
But it wasn't, and it still isn't.
Yes, it's mostly the use of highly efficient LEDs that make this a fantastic idea. Most people who don't have electricity available burn stuff for light which is both highly inefficient and very dangerous (particulate matter + fire risk)
Also I read somewhere else that it could be made a lot more portable / practical using a wind-up spring to store energy rather than lifting a heavy bag. The gravity method necessarily requiresa heavy weight to store potential energy, while a spring can store the same energy in a smaller / lighter / more portable package.
But all in all, well done, good job!!
I imagine it's a simplicity / cost thing. A spring and associated winding mechanism costs more? Likewise, I imagine, a dynamo-charged battery as in any number of wind-up torches in a shop near you.
For long-term reliability, I would have thought a solar cell and battery better (ie directly stored sunlight) No moving parts to fail. But I guess poor folks can't afford the extra capital outlay even if it did come with a 25-year guarantee.
"You don't have to carry the weight around...".
Allan, I think you did not read Charles' post to the end. You want the light to be portable within your dwelling - either to light up another room, or to provide more concentrated light in a particular area (to study, for instance). You are not going to empty the bag and refill it every time you move it about.
Here in South Africa (and elsewhere on the continent) numerous people die or get horribly burned through candles or kerosene lamps falling over (for whatever reason) on a daily basis. Added to that numerous shacks get destroyed, increasing the misery.
This light has the potential to save numerous lives and reduce the number of shack fires and should therefore be applauded and supported. As far as I am concerned just one life saved makes this a worthwhile project.
Some recent examples:
The video doesnt work for me, but it reads like a neat idea.
I think its a hypermodern version of the knijpkat(No idea what the english word is), a WWII era latern that you could power by repeatingly putting presure on a lever:
I remember one of my history teachers bringing along such a device one day. I'm pretty sure most country's had similair equipment.
The gears of a "knijpkat" - literal translation: "squeezecat" - make a sound not unlike the purring of a cat (Felis Catus).
On top of my "knijpkat" is imprinted: "MADE IN HOLLAND - IMPORTE DE HOLLANDE - TYPE 7424-03 - 2.5 VOLT - 0.1 A" with the Philips logo, the one with double-cross on either side of the channel, in the middle.
Modern versions with 3 LEDs, a rechargable battery and a crank are available (Made in China). Their plastic gears make a softer sound than the 1940's "knijpkat" made of steel and pertinax.
Wind up lights are far better. For the same price - or even less - you can get a clockwork lights that are portable and thus more useful.
I expect 99% of the commentards here have never lived for extended periods using 3rd world lighting. I have.
Rule number 1 is that you don't try to light up a whole building. If you need to go to another room then you take the light with you. That means you need a portable light. A device with bags of rocks is not at all portable.
But it is British!... whatever that means.
Pendulum based clocks use pull up weights for power source
for clockwork dynamo
LEDs - think bicycle lights - were incandescent, required D cells, lasted 8 hours, now use two AAA and last all winter
Having been out to some of these cultures I would love to live a different life in a mud hut without all the western technologies. Many of the people in these cultures look at the way we live with pity.
If you live in a mud hut or similar as the people in the video did you don't need a gravity light to attract mosquito's harboring malaria or such like. You simply go to bed and get up when the sun comes up.
> Having been out to some of these cultures I would love to live a different life in a mud hut without all the western technologies. Many of the people in these cultures look at the way we live with pity.
Bizarre that I get all these funding calls to pump money in the direction of people obviously dying on their arse, the way mother nature intended.
"Having been out to some of these cultures I would love to live a different life in a mud hut"
Well, what's stopping you? Your current bank balance will pay for a one-way ticket to a suitable developing country.
Oh! You don't actually want to live a hardscrabble subsistence farming lifestyle with no modern medicine or technology?
Yeah, I thought so.
I took antibiotics once in my life. Had a severe reaction to them and have never taken them again.
That said modern medicine is I believe a fantastic thing - and I wouldn't want to put anyone down who is involved in the research of such medicines . You can (with a bit of luck) live or at least have a life without it though and billions have done so before.
Industrial Sewage Systems are also undoubtedly one of the best inventions known to man. That said there's a again a hell of a lot of people managing just fine without. In places that are not over populated this is not such a big problem. Where the mud hut was shown I doubt they'd have a problem. Fresh water is more of a problem .. something i am always happy to help see resolved. Some of the large cities like in India where sewage is more problematic... I wouldn't like to live like that. Maybe much of the reason for that population density is possibly where they are pushing for western ideals.. (I'm no historian though so feel free to point me wrong).
I don't have all the answers for sure. It's sure good to know everyone else is so happy in their box offices and houses and the constant rush. That the endless supply of goods from slaves in China or where ever is enough to keep everyone going.
To start pushing our consumerism on other cultures though does scare me.
When these light devices break who will recycle them? I've visited one village who were making significant money from travelers. They started buying mobile phones and other electronic items. When they stopped working they'd throw the phones on the floor - expecting it to decompose like everything else in their lives.
Before long these places could become a dirty plastic dumping ground...kind of like around here actually...
The gravity light on it's own does sound like a great invention - simple and effective. Maybe on reflection such devices do have a place - where interference has already been too great. On the edge of Cape town there's people connecting their own power cables up to live electricity pylons to pinch electric for their televisions (probably donated innocently by someone thinking it can't do any harm (KZZZRT?!)
Maybe with a few years of dev they can produce a gravity powered TV?!
I stand by my original comment though... you don't need it in a mud hut.
Get down voting :-P
Well I have had to take antibiotics more than once, and not for just I have a cold reasons but because without them I would have been in serious trouble. I think you'll find generally they save more lives than kill.
Admittedly mud huts probably don't need great sewage systems, and clean water is more useful. I was maybe using hyperbole to point out with that and hot tropics that the amount of nasty things you can catch and be infected by goes up, and that some western things are definitely useful.
As far as lighting goes, I have never noticed it to make that much difference with body heat, and smell mosquitoes find you in various ways, and I have been bitten in the dark plenty of times.
I'm pretty sure decent lighting at night is quite a useful thing though, it tends to get dark early and the sun goes down fast. If you can find a good argument for not being able to choose when you need to see easily then fire away.
"You think "they" didn't have such things before white man came along? Really?"
Guns- No, these were a "western" concept - sure we gave them out to whichever indigenous communities we thought would use them *with* us rather than against us - but we only gave them to the tribes/communities we liked. As a result those with guns found they could decimate their opponents (and in cases where we gave them to everyone; each other.)
Disease - Yes, we gave 3rd world countries a lot of our diseases. Not that they didn't have any of their own - but they had a modicum of immunity to theirs. It was the introduction of western diseases such as smallpox that devastated communities of 3rd world countries who had no exposure.
torture - sure, all humans could inflict pain on each other - but it took people such as King Leopold II to truly show how brutal humans could be. Whilst cutting the arms off people who didn't work hard enough in the rubber plantations could be filed under "brutal dictatorship" (which is, for the most part, how the Belgian Congo was run) I'd say it also fits pretty well under "enslavement" too (although I think we've got plenty of examples of how the west has given Africa slavery).
Colonisation - I'm sure there were conflicts and attempts at wiping each other out amongst local tribes before we came along, but never with the kind of force or scale that we used. The fact that many African nations now speak French or a variation of Dutch demonstrates what sort of effect we've had.
Apartheid - Seriously? You think native africans came up with this?!
Segregation - Not only in places such as the U.S, where Africans were considered to be lower class humans (and not even citizens for a long time) but in Africa as well - In Rwanda the genocide of the Tutsi's at the hands of the Hutu was in no small part due to the efforts of colonists deciding, based on arbitrary physical attributes (which, admittedly, did have some basis in tribal history, but was still no basis on which to decide which people were "better") to decide who would effectively be upper and lower class citizens.
These are things that we "gave" them.
Not reading history books doesn't change history.
"Not reading history books doesn't change history."
Reading only selected histories doesn't change it either. Guns, Maybe I'd agree but they are only a better weapon. Weapons are pretty much indigenous everywhere. Colonization, slavery, bigotry, hatred, disease, every location has their own home grown varieties. What the west did was to industrialize the whole thing.
> Weapons, disease, torture, brutal dictatorships, apartheid, colonisation, enslavement, segregation - you're complaining about giving them *this*?
They had all of these things before the west got there.
Do you really think Africa was a wonderful paradise where everybody lived in peace and love before the west got there?
The tribes of Africa have been fighting and enslaving each other for centuries.
Actually, many of those people use fires in their huts to see at night... which negatively impacts their health, means less wood for other purposes (like cooking), and has all sorts of other interesting side effects.
I would imagine there are many people (ones who are in mud huts because they are poor, not because they are defending tradition) who would welcome this, and for whom the cultural impact is positive, not negative.
Regardless, I think that decision is best left to them... not us.
"If you live in a mud hut or similar as the people in the video did you don't need a gravity light to attract mosquito's harboring malaria or such like. You simply go to bed and get up when the sun comes up."
Sounds pretty defeatist to me, why would you want to be a slave to the environment like that?
I have never understood why traditionalists try and preserve something not worth preserving.
If modern tech can improve lives (as this lighting system can) then it should absolutely be used, I mean, who the fuck would prefer to live in a smoky, carcinogen filled hut when a clean source that fufills the same purpose exists?. Yes, i know they cook with the fire as well as use it for light, but there is better tech for that as well (solar oven).
Incorporate a bug zapper and the mosquito problem is reduced as well.
Funny - I thought malaria pre-dated artificial lighting. I always thought that those pesky mozzies fount their way around by sense of smell. The moment you turn the light on, that annoying meeeeeeeee noise stops, and you can't find the bloody insect to swat. Maybe that's only Italian hotel mozzies, though. Or maybe you are confusing mozzies with moths?
That aside, wouldn't people be happier with more usable hours in their day? Eight hours sleep is plenty, but the sun is down for twelve-ish hours (near the equator). Which is why they use fires or candles for light, which is wasteful, hazardous, and smoke inhalation is a long-term killer.
You see it as bringing medicine, food, electricity, roads, and telecommunications to these poor bastards scrabbling in the dirt.
They see it as bringing smallpox, gambling, alcohol, drugs, racism, marginalization, despair, and suicide to a culture that was doing fine without your fancy gadgets (and now that they know about them, can't afford them anyway), kthxbai.
Mind you, the original damage of colonization is already done. So may as well give them cheap light to educate themselves by at night.
Conrad's Heart of Darkness
- there is mention of different lights being used as markers of status... the officer-classes were allowed (clean) paraffin wax candles, the lower-class Europeans in the camp had to use tallow candles that were unpleasant to work by.
That's like saying that it's actually nuclear powered because ultimately the thing that gave it the potential energy (by lifting it) got its own energy from the sun (indirectly, via plants and possibly animals). The sun being one big nuclear reactor, this little LED is actually nuclear.
On a less obtuse note, are you saying that 'battery powered' devices aren't, because the batteries have to be charged by something else?
could save people relying on biomass fuels such as kerosene, which are bad for one's health
er, since when has kerosene been considered biomass? Anyway, it isn't directly bad for one's health, neither is the dung that is burn for heat and light. The problems start with the soot caused by burning them inefficiently in enclosed spaces.
Solar for lights isn't that expensive and there are several projects which are installing low-cost solar generators, which make a great deal of sense in much of the third world. Given Andrew's generally sceptical views on climate change the article is slightly ironic as people like Amory Lovins have been banging on about giving cheap, reliable and low power renewable technology for the third world for, er, decades.
Still, it's a good project and I hope it does well.
Well, you can make biokerosene, which is what Andrew was driving at.
"Biokerosene"? In the third world? If they have got the process to do that in the wild then they don't need lamps like that. Kerosene from biomass is generally associated with greenwashing/tax efficient strategies from the aviation industry. It's plain and simple paraffin for that lovely, sooty flame.
"Solar for lights isn't that expensive "
For the western world it isn't. For the developing world, a bit more. Plus, solar panels can't be fixed or rebuilt, and to provide light when the sun isn't there, require batteries which also lose efficiency / need maintenance / replacing.
A mechanical contraption like this is a lot more robust and easy to maintain. No reason a device like this couldn't work for scores of years* , even taking into account changing teh LED every 10 years or so.
*unless it was built to built-in-obsolescence specs as most technology for westerners' consumption seems to be these days
This is NOT what the patent system is for. If this gets a patent then the new European Patent system is well and truly fscked. And if these "inventors" apply for a patent, then they're as bad as all the patent trolls that came before them.
This is bleeding obvious and there's a ton of prior art.
This is exactly the thing the patent system was supposed to prevent: wasting good ideas on people who can't pay for it. But while running lights may be fine and dandy, charging mobile phones surely is not! Or have the guys at Apple forgotten to patent that one?
While we are at it, let me be the first to file:
- "Storage of energy by moving an object in a gravitational (or other) field"
- "Conversion of mechanical energy to electrical energy via a generator"
- "Use of gravity to exert a constant force on a weight"
Now then, you may be on to something! Replace hamster with your own local livestock of choice e.g. live near the Serengeti? Replace hamster with Cheetah (scale wheel to suit, but how much power?). Maybe not much torque but pretty good speed. When will they harness the power of the annual Wildebeast migration (I'm thinking travelators along all those crocodile infested rivers they have to cross, but you would have to react the force applied by Wildebeat running from croc. into the travelator some how). Scoobee Doo springs to mind....
>When will they harness the power of the annual Wildebeast migration (I'm thinking travelators along all those crocodile infested rivers they have to cross, but you would have to react the force applied by Wildebeat running from croc. into the travelator some how)
Best. Episode. Of Gladiators. Ever.
I would say the light is gravity powered. The unit has a store of gravitational potential energy which it converts to light. Yes, the unit is "charged up" using muscle power, but that is no more sensible than saying that my wireless mouse is steam powered because the batteries in it where charged up using electricity from Didcot Power Station.
I recall seeing gravity powered radios almost 10 years ago working on the same principle - a cord with a large weight (e.g. 10kg) on the end which was slung over the nearest tree or pole. Same principle except for what the generated current is being used for. It's essentially the same as those clockwork radios except the potential energy is gravity instead of a spring.
I assume a light wouldn't draw as much power as a radio so it could either last for longer, or the gravity drop would be less, or some other variation. There are plenty of wind up torches too. Could probably produce gravity powered USB charger too assuming the weight and cord length was sufficient to make it viable.
It's powered through conversion of potential energy into kinetic into electric into EM - hence by gravity.
The method of initial charging or recharging is irrelevant. Petrol tanks also need to be filled up before they can be used but nobody is trying to say that internal combustion engines are human-powered or gas-station-pump-powered.
'this light is not powered by gravity. It's powered by the human who lifts the weight onto its hook.'
The light is powered by a conversion of stored gravitational potential energy. You are simply taking whatever energy conversion process came before and claiming that that's the one responsible. You could just as easily say: -
'this light is not powered by the human who lifts the weight onto its hook. It's powered by the chemical energy in the food eaten by the human.'
'this light is not powered by the chemical energy in the food eaten by the human.. It's powered by the nuclear energy of the sun that grew the food eaten by the human.'
Basic physics tells us that it takes approx 98 joules to lift a 10kg mass up 1 metre - how much of that do we get back? A 0.05 W LED consumes 90 joules over 30 minutes (1800 seconds). Gonna need a big weight or a long rope (and you'd better get good at Olympic-style weightlifting!) to power the average set of LED Christmas lights...
A pully system could allow even a child to raise a great big bag of rocks, pulling a long rope hand over hand (against a safety ratchet) which would still be faster than winding up a torch. It might be better if the mechanical stuff was all made locally and the only thing they has to buy was the efficient LED/dynamo component.
They were created with poor people in mind, who couldn't afford batteries.
But it seems the majority of wind-up radios and torches are on sale in Lidl and Aldi as gimmicks rather than in Africa as really useful appliances.
I fear the same will happen to these lights. The tooling and manufacture already exists for wind-up lights. I don't see how a weighted light with a cord is going to succeed where wind-up technology failed. The real problem with many poor countries is the money they have is spent on AK47s rather than radios and lamps.
Batteries are expensive.
Batteries are not nice things to have decomposing into your soil when you've slung them away.
Batteries can't be recharged indefinitely.
Batteries may not be as efficient as this method of energy storage (that recharging batteries get warm is a clue)
Batteries are harder to repair than a piece of rope and sack of stones.
I have a wind up LED torch and I find it quite useful. It's wind up in the sense that there is a handle attached to a dynamo and you turn it for 60 seconds and it stores enough charge for maybe 10 minutes. It's fine for putting the rubbish out or going up in the loft. I have another torch I got in poundland which has a squeeze handle and is okay at a pinch but doesn't hold much charge.
I was once given a Baylis clockwork radio and the thing was more trouble than it was worth. As a radio it had an excellent sound but it only lasted 10 minutes per charge. The windup mechanism packed in after 20 winds and would rapidly spin itself out without charging anything. Gravity should in theory be simpler providing the drop was correctly regulated.
Anyway there is potential for these things in Africa but I think most will just end up being sold with the rest of the shit that Marks and Spencer, Debenhams etc sell around christmas time along - golf ball polishers, fart noise keychains, whiskey flasks, Stig mugs and suchlike. A crappy stocking filler.
I do think tech can help developing nations though. Especially solar stuff - cookers, stills, lights, radio etc. People have to trek for miles to get fuel when they are sitting directly under a giant fire ball capable of cooking their food for them with the aid of a few mirrors.
Your problem is, the drive belt in your wireless wireless has stretched. It can be replaced easily (field-maintainability is designed into the set). The outer case separates into two, and the scary mainspring is concealed behind another tray -- which you don't need to remove just to replace the belt. Wrap a piece of string around the pulleys, and subtract one millimetre for each centimetre to allow for stretchiness. Order yourself a new belt from CPC or wherever, and you should be good to go again.
My Freeplay gives me almost one minute of listening on FM per turn of the crank, with the volume turned up just loud enough to be heard over the sound of the spring unwinding. It's nearer 30 seconds per turn, when loud enough to listen in the shower (radio on the bathroom windowsill; it's not waterproof).
You've misquoted, and then started your reply effectively adding the bit you snipped out.
The correct quote you should have used was, "it seems the majority of wind-up radios and torches are on sale in Lidl and Aldi". I'm going to have to deduct two points from your score on tonight's quiz.
Out of interest, how many are actually on sale countries where poor people live?
Quick question for the usual El Reg geniuses of which there are many. As the device is self powered by the weight of the sack, would it be possible to use some of that power when the sack reaches a certain point to bring the sack (slowly) back up to the top to release it again, possibly with a counter weight on the other side which starts to go up when the one goes down, possibly equal weights and using tiny amounts of power to allow one side to go down rather than staying equal? As long as it generates more power than it uses it should be able to ensure the light stays on as long as required rather than for 30 minutes or an hour?
Or a spring at the top, the bag on one side goes up and the other goes down, when the bag reaches the top it runs in to the spring which when compressed enough releases the force which starts to push the bag down and pulling the other bag up? As both bags are equal weight it would still require a little bit of power to stop it from stopping in the middle, but again, if it can generate more power than it uses it shouldn't be an issue.
You are over 100 years late with that idea.
Back when you could actually patent a perpetual motion machine as a power source it would have gone down a storm.
Hint: The energy required to get the bag back up is exactly the same amount as it gave you on the way down, assuming a system with no losses (tough shit there too). Thus there's nothing left to run the light......
"....As both bags are equal weight it would still require a little bit of power to stop it from stopping in the middle, but again, if it can generate more power than it uses it shouldn't be an issue." Don't be silly, the idea of a cat with a piece of toast with the buttered side down strapped to the kitty's back makes a much better perpetual energy generator! (Evidence for this theorem to be found here (http://www.flycatfly.com/flying-cats).
In seriousness, it may be technically feasible to design a counterweight system to prolong the action, but it would add massively to the complexity of the device, its cost and possible problems in operation, whereas getting Mrs African Wife to scream at the kids to lift the bag again is a lot simpler and more economic.
You've just invented a perpetual motion machine. I can't see any flaws myself. :-)
On the off-chance you're actually completely serious, no, it is impossible. For it to work would break several laws of physics, as any 14-year-old physics student should be able to explain. If you don't have a 14-year-old to hand, here goes:
In the light, the energy to power the LED comes from the food a human eats. His or her muscles convert this stored chemical energy to motion (kinetic energy) to overcome acceleration due to gravity and lift the bag from the floor to the top of the rope. The energy is stored as gravitational potential energy in the bag at the top of the rope. As the bag descends, this gravitational energy is converted back into motion (kinetic energy) . This kinetic energy is converted by the mechanism into electrical energy and that electrical energy is converted into heat and light by the LED. Apart from the fact that some energy is lost to the environment as heat (largely due to friction) at each stage, once the energy has been converted to heat and light by the LED there is no way to convert it back to the energy required to lift the sack.
No - what you are proposing is a perpetual motion device and such a thing is not possible.
The sack, upon being raised, has a certain potential energy. When released, the energy is converted to electricity. Energy is lost in the system through friction, transmission losses, conversion losses etc. You could use some of the energy to raise another weight but you'll never raise it as high as the first weight was raised. And if you raise another weight then you have less energy available for running the light.
You can change the length of time the device will create light by altering the gearing, the weight in the bag and the efficiency of the conversion system / LED. Adding reciprocal weights won't do anything useful.
"... if it can generate more power than it uses it shouldn't be an issue."
If it actually could do that, it would be an enormous issue. Anyway, the perpetual motion machine has been invented (or 'designed') many times throughout history. For some reason, a working model has never been constructed.
98ish joules to lift a 100N (10kg) bag by 1m. in a lossless system you would need 98ish joules to bring it back up. That would leave no energy to power the system (LED). You would need three bags to power the system (LED) AND return one bag to the starting position. Better to put two bags on to begin with and drop slower.
"if it can generate more power than it uses"
You would be a very very rich person indeed if you could figure this out.
If that was a genuine question, I guess it is simply confusion on your part, and teh downvotes are ungenrous rather than enlightening. The point where your vision falls down is this:
" As long as it generates more power than it uses"
By definition it will always generate less power than it uses, and that power is being used to keep the light on. You can't use the same power to both lift a counterweight AND keep the light on.
I'm pretty sure I didn't mention perpetual motion, more along the lines of a see-saw, at the moment it's half a see-saw with the one side dropping and staying down, but with a see-saw you put force into one side (that'd be the start with the human bit) and it doesn't just stop, it keeps going until the other forces catch up with it and stop it extending the uptime of the light past 30 minutes. That is what I was asking about possibility, not the possibility of keeping the light going for eternity which would be a pretty silly thing for a light to have to do in a persons home, or shack.
Though in fairness I did invent what I think is a perpetual motion engine about 5 years ago, but I'm still running tests on it before I can actually conclude it is a perpetual motion engine, once it stops I'll be able to give the definitive answer........
I'm all for any advances to help out people in the poorest situations, however I have a couple of problems with this design having worked in Africa.
1. Dust, the clockwork components will jam easily.
2. Getting up every 30min to lift a very heavy bag will be a problem for many.
3. if it can only power a LED for 30min, that connection isn't going to be much use for charging a mobile phone or anything else.
4. pump action and wind up torches have been around for years, cost less than $1 and are portable.
He was originally tasked to create a cheap solar light to take advantage of the abundant solar resources available near the equator, and I have to ask, why aren't the people who originally tasked them supplying the funds they're now chasing? Probably because they ignored the brief, but there may be other reason too.
This appears to be western thinking along the same lines as "lets just give every person a mozzie net!" which results in the nets being used as fishing nets which is destroying the fish stock in rivers and especially Lake Tanganyika as mosquito nets will capture everything not just adult fish.
The most impressive achievement in this arena is with Corus (now Tata) and their PhotoVoltaic Paint, however it's still at least 5 years away from being available.
So it's like clockwork, or old-fashioned grandfather clocks.
And it might produce LED light for the stated 30 minutes, but we're still talking about the same amount of power as lifting a weight up a metre or so. That takes it into tiny amounts of power that can also be stored in clockwork or, say, an even-cheaper, mass-produced, rechargeable battery. "Environmentally-friendly" once in operation, yes, but hardly "bringing light" to anyone who doesn't already have it (and it's doubtful that the cost of creating and shipping the device is actually doing much that is overall positive environmentally, especially with the LED's and the strength of components to hold the weight steady).
It's clever and we can all go "wow", but I just don't see the market. Even the clockwork radio died a death:
"After Baylis lost control of his invention (the clockwork radio).... units switched to disposable batteries charged by cheaper hand-crank generators." (and although you might own a clockwork torch, like a lot of people, when was the last time you owned one that didn't use rechargeable batteries in it or that actually was worth the hassle to wind up for the amount of light it gave compared to, say, just about anything else - batteries, electricity, kerosene, even a lit-match? Last time I tried to use one, I got tired of having to keep cranking it - because it hadn't been cranked regularly and the internal battery was not holding a charge well - while trying to do a simple job in the fusebox and ended up just putting a battery torch down the hole)
I think we're over-simplifying and under-estimating people in third world countries here if we think that they need these sorts of things so desperately - like the "bottle in the roof" lighting... are you honestly telling me that people sat in the dark rather than collect a piece of broken glass, or even just put a hole in the ceiling? Maybe it just wasn't that important to them? And that particular invention required plastic bottles (probably harder to find than just "something clear to cover the gap"), water and bleach (to stop the water going green) and only worked, shockingly, in daylight. So it was a pretty hole. It's like the "spoon made from a fork pushed through the bottom of a polystyrene cup" image that roams the Internet - clever if you think of it on-the-fly and get to use it that once, but I can't see quite what problem it's solving long-term that doesn't have a better solution.
If you desperately need lighting from a bunch of low-power LED's and are willing to stumble around in the dark with a heavy weight to get it, I'm sure you'd be equally as chuffed with an solar-charging-LED torch - the kind of things we give away with Christmas crackers now. And I'm not at all sure that something you routinely have to move kilos of weight (from a suspended hook) by hand to activate would last even as long as the torch would, in terms of sheer robustness (I'd give it a month or so of constant use before the gearing went).
The real benefit of this new device is that it can be left on a shelf indefinitely with no worries about battery leakage etc. So it's an ideal thing for people like OXFAM to include in emergency kits. Take the kits to people who have just suffered a disaster / been displaced by fighting and they can just rig it up and have some light in their emergency accommodation. No need to have relatively expensive stuff like solar panels or batteries in storage.
Some people hereabouts are looking at things with a western, nice safe / warm home view.
An idea I had a long time ago, which is blindingly obvious, is for small communities to have an old bicycle rigged up on a fixed frame with the rear wheel replaced by a dynamo charging some batteries, that would be used to power the village radio, LED light, charge up mobile phones etc. The fit young people could jump on and make their 'contribution' at any convenient time, and a simple LCD display energy meter would display how much they had contributed - this gets some competition and social kudos going.
All the parts required are mostly generally available, understandable and fixable by many people, though the control and monitoring package may need to be donated.
Hehe, we had some fun in the pub beer garden the other month... a couple of the regulars came in with half a bike fitted to a stand, with dynamo, switch and car headlamp unit. You coulc switch between no resistance across the dynamo, the dimmed light and the full headlight- at which point cycling became very hard.
The comedy arose from the effects this concentrated physical exertion had on us, our hearts and lungs being sub-optimal due to being.. well, pub regulars.
Can anyone do a back-of-the-envelope estimate of the efficiency of charging a lead acid battery by this method, compared to the weighted rope method outlined in the article?
(My intuition suggests the rope is more efficient, since it is quieter and doesn't get as warm, but I may have overlooked something)
Like the clockwork radio, this device replaces a cheap, efficient solar voltaic solution with intricate mechanical parts and a dynamo. It will be hard to make the mechanism robust while still cheap. Actually, I doubt it will be possible in any case to make it cheaper than solar LED lights, since you can buy thgose for your garden at under a pound.
And in practice, it won't be any more repairable than a solar cell and battery either. (i.e. not repairable)
The point of this design is that (unlike the solar/crank systems other posters are suggesting) there is no rechargeable battery - obviously a deliberate design decision chosen by the designers.
So why make this choice -
cost (good longlived rechargeable batteries add cost and complexity to the electronics)
longevity (rechargeable systems have a finite lifetime - I have solar garden lights that lasted less than a year)
maintenance (fewer moving parts and simpler electronics)
no delicate solar panels that have to be cleaned/aligned to the sun/cabled to equipment/stop working in the rainy season.
I think the design is simple, easy and safer than kerosene lamps, and a better solution than more complex designs.
I think you'll find this design has more moving parts than your solar garden lights.
And the mechanical components in this will wear, too. If it's made out of a significant amount of plastic for less than $5 then they will wear quite quickly. Especially if the weight hanging off it is large enough to be useful.
... a limited understanding of the word 'poor'. With a cash income of 80 cents a week, this is better than a month's income in rural s areas of India.
Neat idea, but useless if you are on the grid, which is to say, fairly poor but able to afford incandescent light bulbs, and to expensive if you actually are poor.
"You need gravity to make it work but that's not where the energy comes from."
And suddenly you're in the same boat as the people claiming the light is muscle-powered. And in that case, I refer you to the answer given above by Lexxy: in the end it's all gravity powered.
No, it isn't !
Weight on ground, energy used to lift weight to height above ground,physics well understood, energy released again as weight falls to ground - really it's not complicated - where on Earth do you think it comes from ?
Just potential energy - it's no hard. If you tensioned a spring the energy wouldn't come from the ground state of the spring -it would come from the muscle energy required to stretch it.
I like the idea, as long as the mechanism can be made reliable over the long term -- gears wearing out, plastic becoming brittle and breaking, dirt entering the works, etc.
I'd like one as part of the earthquake emergency kit. Sold in the first world for this type of use could increase economies of scale and reduce costs.
I'm thinking about putting a bigger version of this in my house. Two bags, one full, one empty and tonne of rocks. Instead of going to the Gym. I'll carry weight upstairs and put it in the top bag of the generator. Over night the full bag will descend generating power and lifting the empty bag. Repeat each might moving the rocks from descended full bag to the higher empty one.
Cheaper electricity bills, No Gym membership, Ultimate fitness. Win- win-win!