Gravity Light: Our Renewable Energy Future

Gravity Light

Gravity Light. By GravityLight (GravityLight) [CC BY-SA 3.0], via Wikimedia Commons

Guest essay by Eric Worrall

What could be better for providing light in a poor country with no electricity than a cheap kerosene lamp? A group of renewable entrepreneurs think they have found the answer – meet Gravity Light, a third world LED lighting system powered by lifting a bag containing 12Kg (27lb) of rocks every 20 minutes.

GravityLight Brings Clean Energy to Kenya

In Kenya it’s estimated that one in seven people live without access to electricity. Sixty eight percent of Kenyans rely on kerosene as their main source of energy. Kerosene is expensive as a fuel, and can be dangerous as a flammable in the household. GravityLight is one of several startup companies working to make clean and renewable energy and lighting available to families in Kenya and around the world. The foundation has partnered with Shell to send more than 3,000 lights to families in Kenya.

Read more:

The light isn’t very bright. According to the specification;

Product weight (empty bag) 1.2 kg / 2.6 lbs
Max loaded bag weight 12.5 kg / 27.5 lbs
Nominal Voltage 2.7 V DC
Max current <0.031 A
Max electrical power 0.085 W
Luminous flux 15 lm
Luminous efficiency 208 lm/W
Colour temperature 5000 K
Colour Rendering Index > 70
Beam angle 147o

Read more: Specification Document

But hey, the idea has an endorsement from Bill Gates. And think of the health benefits. Instead of studying for hours by the steady flame of a kerosene lamp, risking DVT from all that sitting down, every 20 minutes someone has to winch up a heavy bag of rocks.

Perhaps the benefits will spread to first world countries. Who needs an industrial economy and a steady supply of fossil fuel powered electricity, when you can have the healthy exercise benefits of owning a human powered gravity light?

403 thoughts on “Gravity Light: Our Renewable Energy Future

    • I have an idea. Why not burn a gram or so of hydrocarbon oil/wax/whatever every 20 minutes? And then, and then arrange a bunch of grams in sequence so you don’t have to ‘reload’ all the time…..Just an idea.
      Think of all those poor hamsters you will save from a life of misery…

      • Yeah, Pop, I’ve got a couple of those, and they work pretty well, with three LEDs . . When I first read the blurb on the homepage, I thought there would be a much longer downside, so to speak ; )
        I also have a few solar charge path-lights I use as if candles, when the power goes out, and have used when camping. I got them for very cheap, A few hours of available light each night should be easily maintainable, in the tropics especially so . . This newfangled 20 minute wonder would be better than nothing no doubt, but I’d much rather have a well designed small solar/battery light.

      • “JohnKnight November 26, 2016 at 12:24 am
        …but I’d much rather have a well designed small solar/battery light.”
        Exactly! We have them all over Australian cities powering lights in public areas like parks etc and signs etc. Work very very well and are almost maintenance free and no need for someone to “recharge” the system every 20 mins.

      • Garrity Power Lite 3 LED Crank Light
        Price: $29.16
        * Self-powered flashlight ideal for power outages, camping, and traveling
        Provides up to one hour of bright light per minute of cranking
        • Three super-bright LED bulbs; sealed, rechargeable NiMH battery
        • Magnifying lens casts a bright beam; comfortable rubberized grip
        • Lightweight, compact housing; lifetime warranty on the fixture

      • Eight years with a Democrat President and it will be a job posted in the internet. Hopefully, by then they will have those Treadmill generators.

      • “have a few solar charge path-lights ”
        Took just the light part of two of those on a camping trip and they were great in the tent.

      • That flashlight uses a rechargeable battery which eventually dies. This scheme seems to have no battery being charges. The power is generated as needed. So the equivalent would be constantly cranking a flashlight.

      • Rocks last longer than the rechargeable batteries in those flashlights. I’ve thrown several of those things away.
        Like we say in the engineering world when some marketing wonk thinks they have a notion, “A bad idea whose time has come.”

    • That thing is extremely efficient in use of energy. If it’s 10 kg dropping 1 meter in 20 minutes, that’s 98N X .00084 m/sec or .08 Watts [1 Watt = 1 N-m/sec] . If the LEDs including circuitry are really 208 lumens/W, that’s 17 lumens.
      I once had a US Navy diver on a treadmill putting out about 250W for a half hour. That’s the best he could do. It gives you a lot of respect for the energy in burning fuel.

      • Some more perspective.
        In my mid 50’s, I can still manage 237 watts during a half hour Functional Threshold Power test on the bicycle. FTP testing determines maximum sustained aerobic power. Most of my racing buddies are in the low 300’s. They tolerate my anemic FTP power because if I survive to the end, my all fast-twitch muscle fibers will produce 1,300 watts for about a minute, which is good for about 40 mph in the lead-out sprint train. Professional (un-doped) cyclists are in the low 400’s watts for FTP. The best are around 450 watts.
        But the human body runs around 25% efficiency, so I am burning somewhere north of 900 calories per hour to produce anything over 200 watts. The average human stores a little more than 24 hours of sugar supply in the muscles, or for me about 2,400 calories. At 900 calories per hour, that sugar runs out in about 2 hours, 40 minutes, and from them on calories have to be supplied by fats, which requires 30% more oxygen to metabolize, and since we are already at our aerobic maximum this forces a 30% reduction in power, which is also known as hitting the wall. And the brain runs only on sugar, so hitting the wall and running out of sugar makes you stupid. So for longer courses, we have to dial back the power, or cram in some more sugar during the ride so we don’t run out. In the end, if you expect to produce power for say an 8 hour day, you have to dial the power down to about 100 watts, or you just will not have enough fuel to make it to the end, and even then you will end up lighter due to supplemental fat burning.

    • As a kid, this kind of olden-days technology is exactly what popped into my mind when people said,
      “Many hands make light work.”
      I guess that puts me somewhere on the spectrum.

    • Or a bigger generator on a hill with a shitload of really big rocks, that will do for a whole village! Duh, why didn’t I think of that!

    • This reminds me of the article by the author of Dansdata who ripped into an environmental award winning ‘gravity lamp’ – which he writes no one actually tested before handing out the award..
      He wrote of the Gravia light way back in 2008, but seems you can’t keep a goofy idea down. Well worth reading his thoughts on the matter.
      Possibly this new gravity light is just the inevitable outcome of making learning ‘easier’ for people such that they need never heart their brains by doing something so mundane as researching (I saw this with science advanced diploma’s being dumbed down to the point graduating students didn’t know what pH meant.. and I quit lecturing in disgust)

  1. I saw this in a “BestofYouTube” video a couple years back…maybe 18 months.
    I judge the technology as a stopgap survival type technology. So it is OK. I am not enamored with its novelty.
    What would be better is a more intelligent division of labor brought on by work specialization and a stable government. Erect power lines, build power plants, lay water pipes and sewer lines. This requires social change and the end of tribal warfare.
    Instead we tell these poor people to hang in there with their corrupt socialist governments and live the green religion. Do as the UN dictates, use gravity rock lights, like a green peace wilderness nut job.
    The answer to 3rd world poverty is to allow them to burn coal, oil, gas, and get rid of their tyrant leaders propped up by the UN.

      • Paul wrote – ” The answer to 3rd world poverty is to allow them to burn coal, oil, gas, and get rid of their tyrant leaders propped up by the UN. ” – kind of what Western Society did to progress out of the horse and buggy era

    • “The answer to 3rd world poverty is to allow them to burn coal, oil, gas, and get rid of their tyrant leaders propped up by the UN.”

    • 15 or 20 years ago, I saw a TV program about somebody that made a clockwork radio. It was for similar places, where people had no electricity and no money to buy batteries. Frankly, I think that this light would work better off clockwork.

      • A clock with the same operating torque as the Rocky Horror Chandelier would shear all the teeth off its gears in a day.

      • I am old enough to remember wind up watches. We can sell them to the college snowflakes as an environmentally sound alternative to battery driven watches. Run articles about the millions of watch batteries polluting our landfills. Save the planets! The money will roll in!!!!
        Eugene WR Gallun

      • Good Lord! I’ve got two watches…both wind-up models and I’ve still got a clockwork radio somewhere, I’m obviously completely out of date.

      • Eugene WR Gallun
        November 26, 2016 at 2:28 am I am old enough to remember wind up watches.
        I am old enough to remember them AND still have two working versions, one of which is a 22 jewel kinetic automatic which is about 50 years old and the other a genuine 17 jewel wind up, which is about 60 years old.
        My wife has a vintage ladies Cocktail Watch which is nearly 100 years old and still working.

      • I am old enough to remember wind up watches. We can sell them to the college snowflakes as an environmentally sound alternative to battery driven watches. Run articles about the millions of watch batteries polluting our landfills. Save the planets! The money will roll in!!!!

        I’ve had Casio solar watches for the past 20 years. Never changed a battery, and they have never not worked. And, they’re calibrated with the Atomic clock in Colorado. Never had to set the time.

      • Jeff Alberts,
        The Casio “Wave Ceptor”, I have one one on my wrist also. One of the best uses of solar power. I’m planning on upgrading to a Citizen EcoDrive this year. Same concept, but better quality.

      • The Casio “Wave Ceptor”, I have one one on my wrist also. One of the best uses of solar power. I’m planning on upgrading to a Citizen EcoDrive this year. Same concept, but better quality.

        My latest is a Pro-Trek, much more expensive than I usually go for, but since it’s Casio I went for it.
        I’ve had the Citizen Wingman before. Was not impressed for a $150 watch 20 odd years ago. The band came apart in less than a year, the rotating bezel came off after a couple of years. All battery, had to replace it twice I think in 3 years. Maybe they’re better now, but once bitten…

      • I remember self-winding watches. The had some kind of weight on a slide internal, every time you moved, the weight would slide back and forth, as it slid the weight would hit a lever causing the spring to be wound up one tick.

      • Eugene WR Gallun
        I am old enough to remember wind up watches.

        I remember my first luxury purchase out of boot camp was a Seiko self winding watch. A few months later I bought a plastic Texas Instruments LED watch where to avoid wearing the batteries down you only saw the time when you pressed the button. My first foray into consumer electronics.

    • Regime change for people too ignorant to even know what that is merely means more civil war, warlords, squalid permanent refugee camps, and social chaos in the ensuing power vacuum. Meanwhile the children don’t go to school, and then become easy manipulations for death squad recruitment as illiterate teenagers. Repeat.

      • Been there, seen that, smelled that. These leftarded a$$holes have never had to collect and bury the remains of the children, elderly and women their leftist ideology has systematically murdered. F*ck them.

    • And what do you do in the meantime? Zambia has coal…but the mines have been left to ruin and the rail lines are in disrepair. There are no coal powerplants in operation. Zambia has hydroelctric power, but the twin governments of Zambia and Zimbabwe have allowed the reservoir of the Kariba Dam to drop lower than they should have, so the entire nation is living on rationed electric power, while paying customers (like neighboring nations) get priority. It is all very well to declare a truism about what people should do in the long term…but the long term will not arrive until the political system is rectified to make it possible, and meanwhile the struggle to live is a daily one.
      I do not scoff at this gravity-lamp approach. At least you can give it to someone, and they have usable light when they need it. My cat weighs 16 pounds, so lifting 27.5 pounds is not unduly onerous. My briefcase seems to weigh as much. I would hope the lifting distance is not much more than a meter, just for the sake of comfort.

      • Hi, 2hotel9:
        Gee, whiz. No electricity. I guess I didn’t get through a week of power outage in December during snow, when the only heat I had was burning wood in a cast iron stove, and the only light came from LED lanterns. This would not have been the first or only time. On previous occasions, I used kerosene lanterns, both with and without modern mantles (it makes a difference). I had to put all our refrigerated food out in the snow. We were lucky the municipal water supply was working. And this was in the heart of darkness of liberal Puget Sound (Federal Way, population 75,000…and as many 100-foot-tall Douglas Firs). Oh, yes. I had to chop the wood for burning. We would stoke it to reach 90 deg F in our family room and then bank the fire and rely on the stove to keep residual heat in the house until morning, when the cycle started all over again. We used handcloth baths (not brave enough for cold showers).
        Yeah, I guess we knuckleheads know nothing about what it is like to NOT have electricity. Or…who is the real knucklehead?

        • You were inconvenienced for a few days and that makes you SOOOO special. Your self imposed martyrdom shows you to be a knucklehead. I heat using wood and gas every winter, have 2 kerosene heaters for backups and use on job sites, oil/kerosene lamps(hanging and free standing), have rebuilt 2 spring fed catch basins so we don’t have to depend on municipal water and multiple electric generators for emergencies and job sites. All of this makes me not a martyr, it makes me a prepared, intelligent citizen.
          Please feel free to pull that thorn crown tight on your head and rend your garments and wail about how special you are. I’ll continue to laugh at your dumb a$$.

      • 2hotel9:
        What is the matter with you? In no way am I trying to set myself up as a martyr or anything else. I was just trying to emphasize that lack of electricity in Zambia was a serious problem, and we ought not dismiss it as being a trivial inconvenience. Do you disagree with this message?
        In any case, you came out with the presumption that I knew NOTHING about what being without electricity was like. Well, I knew a little something–and now you chastise me for not living off the land, like you do. I guess if I lived in the middle of Montana, or somewhere between Ellensburg and Spokane, doing so might be necessary. But I have the wonderful privilege of living in an electrified western urban environment, and I have a due appreciation for that privilege. Zambians also have that appreciation…when the government is not turning off the lights on them, paralyzing anything resembling modern life.
        But what I can say about your lifestyle is that it is redolent of luxury, compared to the rural poor in Zambia. Access to, and the ability to purchase wood, gas, kerosene. Springs of water. Stoves & heaters, lamps, LED lanterns, catch basins. My wife’s father was once the Minister of Forestry for Zambia, and his project was to proliferate tree farms (Eucalyptus) to increase the forestation. It got to the point where wood was a valuable export. He died. Time passes. The Zambians have been burning down all their trees to produce charcoal for heating and cooking. Kerosene (paraffin) is dear, when it is even available. Equipment is expensive. Good water is not generally available. In the outskirts of Lusaka, my stepchildren are reporting the municipal water supply is providing dilute and detestable goop (treatment system has not been cleaned out, due to lack of funds and electricity). Mind you, Lusaka is the capital. President Lungu and his chief henchmen go about in Mercedes-Benzes.
        Be smug and enjoy your access to 20th century technology in the midst of the planet’s most technologically endowed nation. It is yours for the taking, and it is good. God bless you. But also pity what the Zambians are doing without.

        • Son, you cried about being out of electricity for a few days, people in Africa, Asia, South America and right here IN America live their lives with no electricity. Tell your sob stories to someone else. You don’t impress me and you damned sure don’t impress any of them.

        • And why are you hung up on Zambia, boy? Did you see that name on NatGEO yesterday? Compared to Zimbabwe, Rawanda, Republic of Congo, Sudan, Somalia et al Zambia is a glittering jewel of progress. Oy vey.

      • 2hotel9:
        Uh, I’m married to a Zambian, and have 3 stepchildren in Lusaka, and numerous family connections (her side) in Zambia and Zimbabwe. But what do I know? I only get the story from the people who are there. I must be a knucklehead.
        In case you haven’t noticed, I have been trying to emphasize that their plight is serious and beyond any inconvenience that we live through. Do you want to argue that it isn’t? Then we have no argument. Have a good night…with or without electricity.

        • You keep acting like one that is what you are perceived to be. Been there and done that, every bit of it wasted by the people IN Africa continuing to embrace socialism. Once they are ready to throw that sh*t off get back to me, till then it is ALL wasted.

  2. It would be interesting to know how many of these could have been purchased, for every return plane ticket to Marrakech that US Taxpayers have just paid for.

    • You win. Best reply in the thread. A 15 watt LED is somewhere around a 70-80 watt incandescent so nice an bright. No need to buy fuel so you can spend the money on other stuff further stimulating the local economy.
      By the way to those who think getting up every 20 minutes to lift a pile of rocks is somehow bad think about the fires from lamps that kill and maim thousands every year. Third world folks would laugh at the idea that getting up every 20 minutes was a hardship. They walk everywhere and do most chores manually. Don’t judge them by lazy first world behaviour.

      • No, TRM. Read the specs again. This thing produces only 0.085 Watts, & its light output is 15 lumen, probably not even as bright as a candle. It is at least white light, though, at 5000K.

      • At the 15 lumens in the specs, it produces a bit more than a typical candle at 12.7 lumens (and it’s ~500X as bright as a firefly). Hardly worth the effort, especially every 20 minutes. Reminds me of Sterling engines: clever, efficient, and cute to watch, but not very useful or practical.

      • sure- just go and trigger all of africa – that’ll be good.
        the light is white? what were they thinking?!
        besides that, it’s cultural expropriation.

      • techgm: The Swedish Navy would disagree with that. Their Gotland class submarine can stay underwater for weeks using its Stirling engine.
        The reason you don’t see Stirling engines in cars is because they are more expensive to make. Mechanical Technology Inc had some nice prototype Stirling powered cars in 1970-1985. here’s a 1986 NASA report on their program.

      • As a child one of my jobs was to maintain the oil lamps. That involved polishing the brass lamp bodies, cleaning the glass chimneys, trimming the wicks and re-filling the oid tanks.
        Looking back it would have been much more fun to lift a bag of rocks every twenty minutes.
        You folks never had to live without electricity for a single minute of your pampered lives……WAKE UP!

      • TRM — OK, you buy it and report back in a year. Make sure you get rid of all electric lights and even candles. No cheating. — Eugene WR Gallun
        PS — You have obviously never held a job where you are physically tired at the end of the day.

      • I did misread the specs. My bad. I thought it was 15 watts which would be plenty bright. At 15 lumens well that is not very helpful. So this now falls into the nice idea but not very practical for the amount of light.

      • It is essentially a common childhood night-light. Just enough light to allow you to walk across a room – not enough for reading without straining your eyes.

      • First, we substitute light for darkness. Then we make the light brighter. This is called Enlightenment (and I’m not being arch).
        Better to light a candle than to curse the darkness. But it is totally foolish to curse the candle.

  3. Funny that it’s always wealthy western new-colonialists living in luxury inventing devices requiring absurd levels of effort and discomfort for the poorest in the world which have the effect of delaying proper heating and lighting and freeing themselves from the poverty of “sustainability” (whatever that is supposed to be).
    Actually kerosene is a great form of heating as anyone familiar with Japanese homes will tell you.

    • My grandfather’s grandfather clock would run for a full week on one raising of the weights – over 500 times as long as this contraption.

      • My wife inherited a late 1800s 8-day kitchen clock that still keeps decent time (it needs a cleaning).
        We also own her parents’ Grandfather clock built in 1970 which has weights for chimes and clockwork lasting 1 week.

  4. Stupid. But for the record, 27 pounds of rocks is not heavy except to unfit armchair Warmunists in sheltered places like Seattle or San Fran.. The old small rectangular twine bound hay bales on my Wisconsin dairy farm went ~60 pounds each, and we heaved hundreds of them per day from baled fields onto hay wagons using bale tongs, and then via a loader again via bale tongs onto the winter hay benches in the upper hay storage of the old barns. Cyrus McCormick invented haying technique from ~1850 to ~1990.
    Much easier now using plastic mesh covered half ton round baler bales and a skid loader with bale prongs. No barn required. Square baler scrapped. Hay wagons scrapped. Upper barn now fit mainly for Halloween parties. Lower barn cows still very happy with hay. Just round steel framed feed pens rather than old linear feed troughs.

    • so those of us with multiple torn discs in spine limited to 15lbs lifting are warmunists?
      would say this has survival benefits EXCEPT it reqs a mount and a weight falling to work.

      • From the linked article:
        “One thing that Jim Reeves wanted to improve was the usability of the product. If a child was studying alone they might not have the ability to lift 12 kilograms of rocks, limiting their access to the light. This new redesign incorporates a winch so that anyone can pull the winch to lift the weights and gain twenty minutes of light.”

      • AMA/American Medical Association: ‘Human Health Impacts From LEDs’
        ‘Report of The Council On Science and Public Health’, 2016
        “Human and Environmental Effects of Light Emitting Diode (LED) Community Street Lighting”
        AMA/ American Medical Association, June 14, 2016
        ‘AMA Adopts Guidance to Reduce Harm from High Intensity Street Lights’
        Seems there are some health and safety factors associated with LEDs and I have a few LEDs.

      • Those references are not based on medical health studies, Barbara. They’re guidance, based on possibilities; e.g. High intensity white light could affect night time rest, according to “large surveys”…

        “The guidance adopted today by grassroots physicians who comprise the AMA’s policy-making body strengthens the AMA’s policy stand against light pollution and public awareness of the adverse health and environmental effects of pervasive nighttime lighting.”

        Nor is the announcement based on proven medical research. It is a statement against light pollution coupled with a bland activist statement regarding vague health and environment lighting effects.
        LEDs emit specific frequencies, not broad ranges of light. Bright white LEDs originally came in response to the desire for bright illuminating light.
        Demand is toward warmer multiple frequency, essentially friendlier home lighting. Light that does not wash out colors; a tough thing for LEDs to accomplish since individually, LEDs do not emit a full range of light frequencies.
        LEDs constructed for plant growth utilize ranges of LEDs to maximize plant growth.
        Similar arrays of LEDs can resemble the broad range of daylight or incandescent light frequencies.

        • There are LED replacement bulbs for home fixtures that are not the blindingly white or numbing blue that most older LEDs produced. Also dimable and 3 level for residential use. I tried the early LED replacement bulbs for MagLight flashlights etc and they SUCKED, newer ones are excellent. I carry a Tasco LED flashlight on me at all times(Never know when you are going to be in the dark) and it casts a strong beam out to 120 feet in total darkness and works very well in crawlspaces and attics. Left it in a drop ceiling, on high, for 3 days. It was still working and the batteries lasted another month before replacing. LED has come a long way in a short time with ZERO government subsidies and no laws/regulations requiring their use. Imagine that! Market forces at work.

        • Also, been using LED “christmas” lights for shop and business applications. Put 3 strings under the bar at my local watering hole and they have been able to stop using most of their florescent overheads. Another business we put single bulb ceiling fixtures up to replace the 4 foot by 2 foot florescents, using a dimable LED 60watt replacement bulb and greatly improved their dining and bar area lighting. Customers immediately began commenting on how much better the lighting was. And both cases saw less electric use. It is an amazing and wonderful world we have managed to stumble our way into!

      • 2hotel9:
        Yes, LEDs started off as basic electronic component usage as a diode.
        Initial light emitting diodes were dull and dim, good for indicator lights.
        The light emission tended to be frequency specific and yes, market desire coupled with customer demand slowly brought LED efficiency and brightness from dull and dim to bright.
        A large part of that demand came from people losing their quality incandescent lights and suffering under flickering fluorescent lights.
        That bright white/blue LEDs took longer to develop. There are several decades of work and research behind the current state of LED lights.
        Light spectrum destruction of vitamins in milk has been identified for several decades.
        If you want healthful milk, you’d transfer all milk from translucent materials into absolute light blocking stainless steel containers. Next up to worry about is oxidation caused by milk exposure to oxygen in air. One can always buy some compressed CO2 to spray in the container to displace that nasty O2.
        There is little difference between LED light and any other light, except that LEDs are restricted to narrow bands of light emission frequencies.

        • I have seen this here in western PA. Pointed it out to a friend works for PENNDOT and he said not to worry! His union has already put in the bid to hire specialty workers to clean them off for only $65.000.000 per year, so we are saved!

      • Unless you have more than one of them, the it will be dark while you are lifting the weight.
        Of course you are going to need more than one if you expect to have enough light to actually do anything useful.
        Of course if you have more than one, you have spend that much more time lifting the weight on each one.
        Eventually you reach the point where you are going to spend all of your time lifting weights, no time left to do anything useful.

    • I doubt the fully grown adults would lift the weight, after the novelty wore off they would more likely delegate to the nearest kid, who would in turn delegate to smaller kids…

    • ristvan November 25, 2016 at 4:27 pm
      Eric Worrall November 25, 2016 at 4:33 pm
      Guys bad bad idea, you are forgetting we are Americans. Well if 27 LBS of weight will produce 15lm what would 150 LBs do. Yup I can see it now “Hey Bubba help me left this”. Ever hear the caution “don’t let rednecks play with anti-matter? Any, all of us would be heck bent on improving it
      Note disclaimer a few days ago during a thunderstorm we had our power go out. I’m still laughing.

    • ristvan November 25, 2016 at 4:27 pm
      Joking aside this is the typical stupid idea that someone who lives in a advanced society makes when trying to help less advanced.
      What happens when something breaks? No hardware store for a couple hundred miles, and if they dispensed with all their lamps and candles?
      You don’t give Tech that the recipient can’t reproduce on their own.

      • Really, how many 1st world consumers even understand the tech they use every day? let alone have the ability to reproduce it.

      • Not needed. Plenty of places where broken tech can be fixed or replaced. In first world countries the infrastructure is in place so that each individual does not need to know how to fix everything.

    • Luxury. We used live in a shoe-box, in road, and every morning we had a load of rotten fish dumped all over us.

    • FWIW, 12kg is basically six full 2-liter soda bottles. Your local grocery store will probably only put two in a bag — three if you ask. A bag with six such bottles is heavier than most folks wish to carry. It’s also heavy enough to possibly rip the handles off a reusable cloth bag. (I’ve had that happen). OK for a healthy adolescent or adult. Definitely too much for small children, the sick, the frail, the elderly, or folks with bad backs.

      • “Don K November 25, 2016 at 11:05 pm
        Definitely too much for small children, the sick, the frail, the elderly, or folks with bad backs.”
        Which you find more of in poor, rural areas in Africa.

    • True. Why don’t they just stop breeding?
      I mean, over many decades the entire world has been hammered by images from Cambodia and Africa full of starving children in countries run by despots. The parents can barely feed themselves already. Seriously, what’s the message here?
      Stop breeding, die out and there’s nobody for the despots to lord over anymore, then they too die out. Job done.

      • Small populations V big ones.. I’ve had this conversation many a time with well meaning folk and it’s a matter of perspective – them imaging our current standard of living but with reduced numbers resulting in a better quality of life.. Sure this is kind of what happened with the Spanish flu ripping through the world resulting in a concentration of wealth for the survivors, but it also meant setbacks that took time (and more people) to overcome.
        But it ignores the efforts of the many people who contributed to the raising of this standard before they were sacrificed. Fewer people means less to do maintenance, less brains contributing to problem solving and clever steps forward.. it means like in many small Australian towns you do not get a hospital or maybe even a school – there needs to be a critical mass of people to have these things – and in the Australian example, there’s a nation of wealth which can subsidize these smaller towns. Paved roads become a luxury.. I’m reminded of the story of a Scot called Calum who spent 10 years building 1 3/4 miles of road by himself. You don’t get roads without a critical mass, you don’t get power stations.
        Telling people who can find themselves penniless and with no social security to keep them alive to stop having children who can help keep them alive seems cruel.. and of course you can’t just have one or two given the lack of available medicine.. child mortality, illness and accidents are going to take a few out of the picture. My wife’s grandmother was married off when she was 14.. had 10 living children who made it to adulthood (no one knows how many did not survive), buried all but one and even some of her grand children before she herself left this world..
        the command ‘Die out’ .. delivered to others seems very harsh. I’m sure you might see this if you think about it from your own point of view? Those images we’ve been hammered with of carefully selected poor people were often to guilt us into making donations to wealthy western corporations to provide aid..
        Look around yourself, without a vast number of people almost nothing you see would exist – it’s hard to have the time to build an iPhone when you’re swatting flies away while you’re grubbing the forest floor for food

      • Thanks for the input, ЯΞ√ΩLUT↑☼N @ November 25, 2016 at 10:59 pm
        But the solution is known: Cheap energy > labour saving devices > increased productivity > time and opportunity for education > more prosperous society > rapid decline in population growth.
        Summed up nicely here: Hans Rosling and the magic Washing Machine)

    • How many times do you have to tell people to boil their drinking water and not to urinate/defecate in their local springs/streams/river? Apparently we have not reached that magical number since we have been doing it for around 200 years now. Perhaps this is also an indicator of why socialism keeps being so persistently embraced in these places.

      • Too right. Why constantly give “aid” when there’s a very high chance that much of it reaches only the despotic grabbermint in that country?
        For the rest, making cheap energy available to those without a means to pay for it except using maybe dung is pointless.

    • “Let the market decide, but for those without any electricity this may prove to be a suitably low tech intermin part of the solution”

      Can the device be ‘pre-charged’ by lifting the weight a dozen or a hundred times?
      Spring controlled pocket watches were designed centuries ago; built upon older technology based on using weights, gearing and chains. Essentially reaching spring controlled perfection early in the 20th Century. Modern wind up watches use a person’s normal motions and activities to keep a watch ‘wound’.
      Now, allegedly, some urban art nouveau students of the electrical grid have again devised a chain driven clock; taking modern non electrical grid society back at least 300 years.
      Such genius.
      Care to lay odds that the dang thing is noisy too?
      I have this little device, an NSD Powerball, for exercise. Just by holding the ball while swinging one’s hand in tight circles, spins an internal weighted gyro. The faster the gyro spins, the brighter led lights flash. There are apparently folks who try and spin the little gyro over 20,000 rpm.
      In a world that easily designs and constructs such devices, one would expect modern society to build a much brighter, less intrusive much longer lasting device.

  5. It’s parallel-thinking to the wind-up flashlight/radio products (which I think are brilliant for when the power goes off, or was never there in the first place when the sun goes down.
    The treadmill analogy, adduced above, is a perfect rejoinder. It’s fine, so long as the jail-birds(?) driving it don’t drop dead of starvation. As the Russians so acutely manipulated the energy-balances to the last Calorie in the Siberian gulags, so we get to the $-efficiency of man-powered (or horse-powered, for that matter) generation at the margin: that is, $-worth of Calories to *just* keep the treadmill operators alive, vs. alt. methods.
    Soon, we hit upon economies-of-scale, and — lo! — the Industrail Revolution makes sense …. RIGHT! (Economies of Scale and Thermal Efficiency seem to be long-forgotten truisms!)

  6. They need a TV and a fridge too. So I would prefer a small windmill or some solar cells with a generator when both fail.

    • Griff is a great supporter of the project in Kenya to deploy 10,000 homes with………a solar powered light and TV.

      • I’ll take door #2. The Scrubber-equipped coal plant with matching water treatment and sewage facility combo.

    • Well, first you have to have cheap energy to o create good jobs so they can afford to buy windmills and solar cells. — Eugene WR Gallun
      Then take away the cheap energy and watch them regress.

  7. I imagine a similar amount of energy could be generated with a handful of loose change and half a cup of urine…
    Now, THAT must be worth a research grant if anything is!

    • Agreed, a bag of rocks is a ridiculous way to produce power. Those little fans you put on top of your wood burner, powered by a sterling engine, produce that kind of energy. Totally safe, they can be made of really cheap materials such as heat resistant plastic. All they need is a source of heat.

    • November 25, 2016 at 5:34 pm
      “Sterlings are not cost effective.”
      What are you babbling about? they use heat from the stove to power a fan. Where is the cost? Are you trying to say that the heat used to power the fan is more then you would get from not having the unit to begin with?
      Name calling is bad form unless I do it,
      respectfully michael

  8. “Gravity Light: Our Renewable Energy Future”
    Well, rail gravity storage seems to be a good idea. So, even though you are just taking a cheap shot at renewable energy systems, you may actually be right.
    As for the gravity light, you don’t even pretend to take a serious look at the idea. I suppose you think the real answer for people in Kenya is to have a proper power grid.. Well, great, but they don’t, and unless you are going to go there and build and maintain it for them, they will still need to rely on other alternatives, and the gravity light actually works, and does something useful.

  9. Probably not a bad idea, actually. If you are out in the middle of nowhere with no electricity.
    These sorts of kinetic electric generators used to be something of a joke, but now with ultra-low power electronics being all the rage among the EE crowd, more and more devices will be able to make use of this.
    I would bet that the system is way cheaper and more reliable than a solar cell+battery combo. If your needs are small and intermittent, there is probably a niche for this sort of thing, just like the old hand crank flashlights, or explosive detonator boxes.

    • i think they already tried the solar powered night light.
      it turns out that you need diesel generators to power the lamps that shine on the solar cells…

    • I still prefer clockwork. But anyway, very suitable for anywhere that there isn’t reticulated power, like Kenya or South Australia.

  10. This would work in America instead of Michelle’s food program. The cycle time would have to be cut down to 5 minutes and any child with a high BMI would get the honors.

  11. To help put this miraculous 15 lumen advance in technology into context – this mini pen torch (see link) which operates from a single AAA battery – can produce 300 lumen max, or 15 lumen in low power mode for 7 hours. Obviously it can be run from a rechargeable battery. It’s just a random example chosen from many.
    I think that I would rather recharge some batteries and have a handy mobile source of bright light – than spend my evenings lifting rocks and straining my eyes in the 15 lumen gloom.
    I’m not saying that Africans should all buy top-notch U.S. manufactured flashlights.
    They should be permitted to choose the best options which suit their needs, as we do.
    But – the fact that a single AAA and LED combo can produce 20 times as much light – tells me all that I need to know.
    I have 3 watts of warm white LED illuminating my desk and keyboard at this very moment. It is sufficient.
    0.085watt would not be.

    • Most lumen claims of flashlights are greatly overstated. 300 lumens from an LED on a usual flashlight budget requires at least 2 watts (even though 15 lumens can be obtained from a single chip LED from significantly less than .1 watt due to nonlinearities that LEDs have). And the LED requires more voltage than a single AAA cell provides, so a boost converter is required, and it costs a lot to get a boost converter that is more than 75% efficient with 1.5V input and ~3 volts output. So, to get 300 lumens from a 1.5V battery is going to require over 2.5 watts or a high budget. Even at an extreme 210 lumens/watt, 300 lumens requires 1.43 watts – nearly am amp from a AAA cell, which a AAA cell can’t do for more than a few minutes, even if its datasheet says a majority of an amp-hour of charge (applicable at a low discharge rate and not considering the cell dead until it is down to 1.1 volts or something like this). 300 lumens is probably what the LED produces at its maximum power when cooled by Niagara Falls, bare from the LED before losses in following optics.
      As for an amp from a AAA cell – once alkaline cells became the common chemistry of D, C, AA and AAA disposable batteries, flashlights using D cells got upgraded bulbs with premium fill gases and with current consumption increased from around .4-.5 amp to around .6-.9 amp. So did some with C cells, although C cell flashlights with the new premium bulbs did not shine bright long enough for most night hiking use. And 2-AA cell flashlights came alonmg, to use the old PR-2 bulbs. And 2-AAA-cell flashlights came along to use special bulbs with premium fill gases and current consumption around .25-.3 amp or so.
      15 lumens is about the light output of a 4-watt 120V incandescent nightlight bulb, or in the range of flat wick kerosene lamps. It is also about the light output of an old-fashioned 2-D-cell or 2-C-cell flashlight using the PR-2 bulb / lamp.
      Also, 15 lumens of 5000K LED light has more effectiveness in dim areas than 15 lumens of ~1900-2000 K kerosene lamp light or ~2300 K incandescent nightlight light because the LED light has greater stimulation of scotopic vision, or a higher scotopic/photopic ratio.

      • google ‘joule thief’. good to the last drop. they’ll drain that cell till it’s around 0.6v.
        with a proportionally short duty cycle, and led can be overpowered in pulses that are very bright and persistence of vision makes the light seem brighter than the same average power at lower but continuous brightness.

      • I never trust any high power battery-LED device IF it doesn’t have a DC-DC driver.
        Relying on stacking two 1.5V cells and then hoping that the voltage is matched to the LED’s needs is a shoddy approach. And then, this would fail to take consideration of the 1.2V of NiMh versus 1.5V of Alkaline. I always prefer to drive LED’s using a constant current source. i.e. I regulate for current not voltage.
        I was aware that there are possibilities for exaggerated claims of high watts and high lumens.
        But, I think that we can expect better fidelity to the actual real-world values from American and European manufacturers, than from the Chinese non-branded market. So, that’s why I chose a U.S. manufactured torch.
        I’ve been using LED’s for torches and lighting, since I manufactured arrays of superbright LEDs to function as backlighting in my off-grid home, back in the 1990’s.
        Initially, these served the purpose of allowing us to navigate in the dark, when the main generator and inverter were turned off, at night.
        Now, I can buy cheap 3 or 5 watt torches which run from a couple of AA’s. They are COB technology.
        A wide band of active material.
        The principle downside, is that they are so bright that I have to put them inside a lampshade so that looking at them doesn’t temporarily compromise my vision.
        Apologies for not going to town with analysis of the technical spec. discussed in my original post.
        I was really only offering a general comparison.
        I think that we can safely conclude that the torch that I pointed to is considerably brighter than the rock-lift assembly. I’m more inclined to doubt the veracity of the rock-lift lumen claims, than the AAA torch’s claims.

  12. It’s some light. That’s better than none.
    Compared to being on the grid it’s rubbish.
    But compared to being off grid and wasting fuel on low energy necessities… it has a use.
    For inconvenience, it’s not much worse than having to get up and put a coin in the meter.

  13. A lot of work involved for just 20 mins of light, for goodness sake! They’d be better off with a string of solar-powered Christmeas lights. At least there would be a chance of a few hours’ worth at a time. Not so good in very shady places though.

  14. I’m sure Kenyans would erect a pole rigged with a block to raise the rocks up high enough to give them an evenings worth. Twenty minutes isn’t much of a span.
    It could have some use I suppose, but it is a bit of a Luddite idea. The feel-good thought that lefty, well-off, white sustainability types are doing something wonderful for Third World unfortunates by giving them dull lights powered by their own labor is a product of an insidious, subtle form of racism that the perpetrators are unaware of. It is built into their world view and out of sight, yet it is part of almost everything they think or do.
    Back in the 1960s, following independence of Nigeria I was puzzled, but only for a little while, when a Nigerian newspaperman said to me “Why is it that Bature (whites) can’t understand that an African can take a handout from them with one hand and smack them in the face with the other?” After being in the country for a while and seeing the missionary ladies in white ankle socks and sensible shoes doing God’swork with the heathens and the “Aid” communities’ patriarchal condescension, I came to see the journalist’s point. The same thing imbues the new world order types view of the world and that’s what pi55ed off middle America in the election and middle UK in Brexit.

  15. Okay, lots of deservedly snarky comments but no one has done the math. So here it is:
    At a luminous efficiency of 208 lm/W, and an out put of 0.085 watts, the light gives 17.7 lumens. And at 5000 K, which is very blue, which makes it dim to the eye.
    A check in my linen closet found a 60 watt incandescent bulb that puts out over 850 lumens at about 2800 K (called “warm white”)
    So it would take 48 of these gravity lights to give the equivalent light of one 60 watt incandescent bulb.
    One LED bulb found at Lowes on the internet, sold as 60 watt equivalent, puts out 800 lumens at 2700 K, and uses 9 watts.
    From wikipedia:
    “Flat wick-type lamps have the lowest light output, Center Draft round wick lamps have 3 – 4 times the output of flat wick lamps and pressurized lamps have higher output yet ; the range is from 8 to 100 lumens. A kerosene lamp producing 37 lumens for 4 hours per day will consume about 3 litres of kerosene per month.”

    • re “Flat wick-type lamps have the lowest light output, Center Draft round wick lamps have 3 – 4 times the output of flat wick lamps and pressurized lamps have higher output yet ; the range is from 8 to 100 lumens. A kerosene lamp producing 37 lumens for 4 hours per day will consume about 3 litres of kerosene per month.”
      As a kid on a post WW2 Soldier Settlement block in rural Australia, I remember well our progression from the flat wick lamps to mantle lamps and eventually the pressurised lamps (all bought secondhand) which seemed to match the increase in amount and complexity of school homework as we progressed from primary to secondary school when fortunately electricity became available.

    • I’ve never experienced life in Africa and I have certainly never experienced extreme poverty – at least after my college years. But Wikipedia left out one major category of kerosene lamps; round wick, unpressurized, incandescent mantle lamps. I have five Alladin Mantle kerosene lamps. The oldest is approaching the century mark and the newest is around 20 years old. Parts and components for all of them are still available. They all work well and I use them whenever the grid goes down due to weather. I also use them just for the warmth and gentle quality of their light, supposedly the closest to natural light. Their design eliminates any objectionable kerosene fumes except when they are first lit or extinguished. Their output is the equivalent of a 40-60 watt incandescent electric light and they normally give me 12 hours of light per quart of kero. Yes, flat wick kerosene lamps are very inefficient, producing little illumination with their incomplete combustion but properly designed lamps utilizing complete combustion and incandescent mantles are safe and effective.

    • 5000 K does not make light appear dim to the eye. For one thing, the lumen is a photometric unit rather than a radiometric one – the lumen is defined in terms of photopic reception by the “standard human eyeball” as defined by CIE. For that matter, how human eyes deviate from “standard photopic vision” in dim light conditions makes them more sensitive to wavelengths from mid-green to greenish-blue.
      Another thing to consider: Peak wavelength of a 5000 K blackbody, as determined by amount of radiometric content per unit nm of bandwidth, using the blackbody formula, or simplified using Wien’s displacement constant: 579.5 nm to the nearest .5 nm, 579.6 nm to the nearest .1 nm. This is yellow.
      The temperature of a blackbody radiator that maximizes its luminous efficiency (according to the CIE photopic function) is about 6600 K. The peak wavelength of that is somewhat bluish, but lowering the temperature increases the percentage of spectral output being in infrared more than it decreases the percentage of spectral output being in ultraviolet due mostly to broadening the bandwidth in wavelength terms.

      • 5000K light sucks. Everything has this weird bluish hue. Feels like everyone is a zombie, (if zombies were blue, that is).
        This is my very (un)scientific observation.

  16. Who, among the smarmy scoffers, here has ever done anything to improve the lot of the world’s poorest? We all understand that this a lo-tech, non-starter in our world, but if a 9 yr. old Kenyan child is helped to learn to read by such a simple device, it’s in very poor taste to condemn it for lack of sophistication. Please, people, think before commenting. Other people are watching this site.

    • +1 We need to encourage technology transfer to those that lack it. Whether they embrace it or not is their choice…. but I don’t see that they would not no matter how simplistic.

      • This is not technology transfer, how do the Kenyan’s repair the darn things if they break? It is simply a feel-good response from some over-educated idiot. They would have done much better to promote the building of coal fired electricity generators & an electrical grid in rural Kenya.

    • The best thing to improve the lot of the third world would be access to cheap fossil fuels and small single cylinder diesel engines… With that you can run small agricultural plants, fishing boats, businesses. You can run refrigeration, freezer plants, generate electricity, us as PTO’s for all manner of agricultural work, engines for fishing boats and commerce…. etc.
      This light is rubbish…. A 5kva 240v generator or 24 volt/240volt inverter system driven by a 8 hp diesel engine would be a lot more practical for a family farm.

    • And using a weight that requires resetting every 20minutes or so, instead of getting cheap large scale power to the poor helps them nearly zip.

  17. The technology of the Grand Father clock incorporated into a light…. So we’re going back to the 1600’s.
    So what comes next? The reinvention of the wheel or the lever?

  18. JH, you’re missing the point. Yes, they would be better off with a one-lunger diesel engine, but are you going to deliver it to them? Nor do they currently have access to ‘cheap fossil fuels’ or even expensive ones. Hoisting a fairly small bag of rocks is something that can be done now. Don’t let ‘best’ become the death of ‘better’. Your situation has nothing in common with a Kenyan peasant.

    • ” Don’t let ‘best’ become the death of ‘better’”
      Agreed. If I was sitting in the dark, and could lift a bag of rocks every once in a while to get light, I would. That might allow me to get an education. Priceless.

    • Larry, I take your point, and ECB is correct as well.
      However the philosophy behind these types of projects isn’t that it’s to be a stop gap until wide scale generation arrives, but to delay wide scale generation. You don’t need to build a power station and grid if the people are shown to be happily lifting bags of rocks for light and have you beaut solar Bar B Ques for cooking on. (Just don’t expect a hot breakfast.)
      “They already have zero emission lights and cooking, why do you need a power station?” It’s about keeping non whites down. Seriously. If you believe in finite resources on the planet then every developing nation of non whites is taking irreplaceable resources from your grandchildren and your grandkids will have to make do with less.
      From this POV, stopping or slowing development is a very good thing.

    • For about 2.5USD one can buy retail small solar LED “pathway” lights. Sold in bulk the price will be much lower. All the little light needs is a switch so it comes on when desired and not just when it gets dark.
      Simple is better, or rather best.

    • An engineer friend of mine worked on a project to develop a very low-tech, minimal cost water-well drilling rig for African use. It worked well, but was never deployed. Why? Because the import baksheesh demanded by local authorities made the rig generally unaffordable, even with subsidies. Rather than play King Canute, trying to halt the tide, the backers [who had VERY big money] withdrew funding. Well- intentioned outside theoreticians will never make one iota of progress in most of Africa. Too much corruption/ greed/ politics.

  19. And we are not going back to the 1600’s or any other time. They desperately need to exit the Stone Age.

      • +1000
        And they aren’t going to be solved by a solution that requires a bag of rocks to produce 20 mins of light.
        They might be solved by that bag of rocks used in a different way however….but that is UP TO THEM to do it.

  20. Candles and lamps aren’t all that convenient if you live three days walk time from the nearest store. Ever been backpacking in the Sierra Nevada? No 7-11s above treeline, nor in the Kern valley nor anywhere else if you forget to bring matches.

  21. I think all the clue challenged brain dead buctflacks should start by reading “The Ugly American” by Eugene Burdick and William J. Lederer. Once they understand the relevant parts of it, possible but probably only after years of contemplation in the lotus position for most of them, they can go live Kenyan style in Kenya, or in the style of the residents of any other place in amongst said residents, for a while. Then, if any of them actually have the brains God gave a grape, they might figure out how to use something readily available right there to do something the people who live there would really like to do but haven’t figured out yet.

    • I agree, and one of the reasons the gravity light is getting such contempt in this thread is that some greens think it is some sort of real solution. I remember seeing an interview with an Indian peasant saying he wanted “real electricity”, not solar panels and batteries. They want to keep the peons in their place.

      • Well Tom, it seems very “Green”. I’m thinking all those ecologically responsible people in California could use this system. I will start selling ” bags of green power” next week (just add rocks). Engineering consulting services extra if you want two lights or air-conditioning or something (1 really big bag or dozens of smaller ones?) Also, they can hire illegal aliens as ” bag men”.

  22. Why not just give them those flashlights with the spin handle? Several hours charge with 30 seconds of spinning.

    • I have a lantern, a radio/flashlight and a flashlight that run on that principle. None give “several hours charge with 30 seconds of spinning”. I’m lucky to get an hour. The lantern and radio/flashlight are pretty much useless unless I’m desperate. The flashlight isn’t too bad—you can wind it, walk until it goes dim, then wind again. None of these seem to perform as advertised.

      • How much you pay for each? What quality of battery and charger are they? You get what you pay for, and with gravity light you get a sack of rocks.

  23. A lot of guys here talk from life in Africa, even if they never have been there and certainly not knowing the circumstances of poor people there.
    When I worked in Tanzania, kerosene in small amounts was 2 $ per litre. Dayly income was 1$, if you were employed. Many are not.
    Kerosene Lamps produce smelly gasses which are not healthy. At night you have to close the door and windows because of moskitos. And evne in Africa it’s cold, so it seems there is som impact on health.
    LED light with 15 lumen you can direct to a table or desk and this is much brighter on that area than a kerosene lamp. If you direct the light with a small angle, its multiple times brighter than 360° surround of a kerosene lamp.
    If you have such a lamp, you never have to spend money on kerosene. So it depends on the price of the gadget.

    • I agree, it is likely a great fix if you can buy it for a dollar and it lasts for years. I recall a visit to a village where there simply was no light for most. This could be a real godsend to them. The negative comments here come from people who live a life of Kings by comparison, and so they simply have no idea. A bit of Christian humility is due IMO.

      • Liter of kerosene would last way longer than 1 week. More like 1 month, or longer if you try to conserve it.
        How long do you think would this thing last, if it costs only $20, with 30lb of weight moving on it every 20 min? With daily use, I’d be surprised if it survived for a month. Something that can last years would be much more expensive.
        But the derision is not because of LED lights, it’s because there is so many better alternatives that had been in existence for many years, like for example crank-powered lights with battery, which gives light for much longer at lot less effort.

  24. I have a nifty little device that is a hand crank 5 led flashlight and radio combined. 30 secs of crank is about 3 hours at max usage. It cost about $25 dollars. Its only problem would be aging on the rechargeable battery but mine has lasted about 10 years so far, it just needs a crank a little more often. This “new” tech idea is totally ridiculous. Im all for helping but for heavens sake you need to really help and not just feel good about sending them crap, they have enough crap.

    • As noted above, I have not gotten more than an hour. Mine are less expensive than yours, I think. However, as other commenteros noted, $25 is a lot of money in Africa. If you’re sending them as gifts, that’s great. They are much better than nothing, and much better than lifting 27 lbs of rock every twenty minutes. As gifts to the people who have no lights, that’s fine.

    • A better than good proposal. The stone age clearly ended when they ran out of stones, and using rocks risks a similar problem coming up, but the world will never run out of UN bureaucrats.
      Enough green UN bureaucrats and the stone age could well be refreshed as the stones recover.

  25. My cousin brought down many 40W equivalent bulbs he got at Cocos to replace the incandescent bulbs here in Cabo, Baja, Mex. He payed $1 per bulb. (I think they are actually 4W bulbs now).

  26. I suppose that you are welcome to do as you please, but the concept of packing 25# of rocks along on a camping trip leaves me a little cold., /sarc A rechargable battery/dynamo would seem more practical.

    • I think rocks are common enough that you can find them where you are, no need to carry them with you. Sand, wood or water would work just as well, too.

    • jorgekafkazar has nailed it.. but instead of using a kid, put a cradle in place of the weight like a garden swing – you want light, you sit on the cradle.. as you descend you get your light, when the light runs out you stand up, wait for the return spring to raise the cradle again then plonk your butt back in the seat for another round. 60+ kilograms with just the effort of standing up at the end might be easier than lifting 10+ kilograms of rocks..
      Note: greenies, you’re not free to pinch this idea, go away – it now belongs to jorgekafkazar and Anthony.. I suggest it be marketed to families with a chunky relative who they’d like to put to use. Marketing-wise, a picture showing ring of happy smiling facing bathing in the glow of LEDs with granny suspended in the middle should do the trick. Optional extras could boost the profits, like a sharp metal spike that could be placed beneath the swing to prompt the weight to raise it’s self when the pendulum runs down..

  27. Kenya is one of those countries where micro-installations of solar cells are working. The houses pay via cellphone that is also recharged. After one panel is paid for, most families sign up for another. The receptacles are reasonably priced and the systems devised for adding more is easily done.
    This product is more suitable for the outhouse or animal/drying shed.

  28. I wonder how many rural Kenyans have a house sturdy enough to hang a 12Kg weight from the ceiling?
    And how long will what appears to be a plastic strap to hang the weight on last when it is in use?
    Finally, positioning this thing so that the light produced is pointing where you want it will not be easy with a 12Kg weight hanging off it.

  29. Lets calculate the efficiency of this great engineering innovation.
    The suspended weight is 12.5 kg and is lifted to a height of 2.4 m, a potential energy of 12.5*9.81*2.4= 294.3 Joules.
    This energy is released over 20 minutes, a power of 294.3/(20*60)= 0.245 watts.
    Now as per their spec sheet the led lamps were is rated at 0.085 watts. We are not talking about the lumen efficiency here, just electrical rating of the lamp.
    Thus, the nominal mechanical to useful electrical energy conversion efficiency is = 0.085/0.245 = 34.6%.
    Well done boys, a bicycle generator will have around 95% of conversion efficiency and I now really love my antique cuckoo clock.

  30. What they need is a generation plant that will run refrigeration so they can spend less time gathering fresh food and more time learning to make iPhones.

  31. What happened in remote villages in Indonesia in past decades, and probably still is in some places not yet connected to the grid, is that some enterprising villager who often had left the village to work elsewhere and saved some money, would buy a small genset then set it up paying a villager to run it for several hours each day. Wires would be strung on poles or on trees to households that would pay a small fee based on the size of the light bulbs in each house, a win-win all round. A free enterprise spirit can achieve much in the absence of a bureaucracy.

  32. The Clinton foundation was in talks to put in a 10 MW Rock plant in Kenya. Which would be more then sufffient to bring electricity to thousands so the they can watch a 15 lum bulb in a dark hut.

  33. Hey! Just think of what we have here.
    This is a guaranteed way to get people to exercise while watching TV. Take old, fat, retired people like me and don’t let me watch Fox News or Oprah without doing some heavy lifting, and I will become a new person. a lean, mean, lifting machine. You could sell these things on TV for $49.95, or two for the same price with only an additional $50.00 shipping and handling charge. You will love it. Your kids will love it. Your cat can will play with it. It’s a great deal!

  34. So, basically, instead of reducing the pendulum load to chunks a child can lift they added in another device that can fail.
    That’s moronic. I don’t think this was engineered well enough.

  35. I think replacing all their CF globes with these is the only way Hillary supporters can get over their ‘literally shaking’ episodes and find some safe space to be at peace with themselves and Gaia again. They can also double as pendulums to answer their big questions for the future, particularly if filled with rock crystals.

  36. 1. Who buys these for poor people? They need tens of millions of these for Africa alone.
    2. What is the carbon footprint for the lifecycle of each gadget, raw material to final product delivered? Does it really save that much emissions in a life cycle evaluation?
    Buy a man a fish, and he eats for a day. Teach a man to fish, and he feeds himself and his family for life.

    • Teach a man to fish, and his wife complains that he’s never at home and when is he going to put up those shelves, and his children say “Not fish again!”

  37. I’m just surprised Bill Gates hasn’t advocated extending the life of billions of slow old computers by installing fast and light Linux operating systems on them, all free and ready to go.
    Actually, I’m not surprised.

  38. There are better solutions already out there. D.light is one brand of small, inexpensive solar lamps. Out of curiosity I bought the S2 and S20 a few years ago and they still work fine.
    The solar cell charges even during fairly cloudy days, and when charged, the S2 provides several hours of light you can read with, and the S20 has two brightness settings and gives more distributed light – also lasts longer. They don’t provide lumens ratings on their web site, but instead rate as “x times brighter than kerosene”. I haven’t bought a kerosene lamp to compare, but solar powered lights like this are a marked improvement for people at the bottom of the financial ladder, in that buying one gets you off the kerosene purchase (and smoke) and lets you extend daytime a bit.
    They offer larger systems, too, and their top-end D30 system can also be bought on a pay-as-you-go approach being adopted in Africa and elsewhere, where the ubiquity of cell phones means you can be billed per usage even while living where the traditional grid might never reach.
    There are a variety of companies and public/private partnerships getting basic illumination and charging capacity out to the non-grid public using the pay-as-you-go approach. People benefit, and it’s not simple charity – they are buying electricity instead of kerosene. Light, no smoke, no inhaled particulates. One step up the ladder.

    • We used a solar powered shed light and had good luck with it—it was surprisingly bright and lasted for quite some time. We put the charger inside in a window so hail wouldn’t get it.

  39. I find it a good idea, if it is cheap.
    There exist cheap flash lights that are powered by hand. They are useful for everybody where shops are far away and shopping is done once a week and one runs out of batteries. I have two at the country house. Maybe I should experiment with a bag of rocks :).
    This goes one step further. Not a bad idea for summer houses that still have outhouses here in Greece. . Or garages and store sheds without electricity extensions. 20 minutes is plenty to find what you are looking for.

  40. Every large village has a well. This could be operated by raising and lowering the bucket. It is still far short of what is needed.

  41. The Wikipedia article on kerosene lamps says that kerosene consumption in Africa for producing light is about the same as jet fuel consumption by the US. And if most of Africa’s kerosene lamps are of the flat wick kind (which I don’t know for sure), which are generally little or no brighter for nighttime illumination than this “bag of rocks” lamp, then a lot of kerosene that poor Africans buy can be used for cooking instead of for making light, and less animal dung gets burned for cooking so more animal dung gets used as crop fertilizer.

  42. No, it’s pretty dumb. Give each kid a bike, attach an efficient generator and a lead acid battery, enough energy for a decent light and TV. The kids will charge it during the day and love doing it. Not only that you can send them to the corner Hut for milk and an hour of TV.

    • I think it more likely that a special spot in hell finally opened up just for Fidelito. May Fidel Castro burn in hell forever.

      • Gareth, comparing Thatcher to Castro is a disgusting insulting display of ignorance. Thatcher was elected, served until democratically removed, and despite your implications, left the UK better than she found it. Castro was a faux revolutionary kleptocratic tyrant who has left his country worse off, and only ended his rule after nearly 50 years when he finally assigned power to his equally tyrannical and corrupt brother. Bugger off.

      • Hey Hunter, you are obviously one of the political ignoramuses who don’t realise that some politicians kill their opponents like Castor did, others get other people to do it like Thatcher did.
        Thatcher and other right wing politicians gave substantial support and arms to countries like South Africa , Argentina, Chile and others so that they could kill their citizens without being hassled by people who complained about “Human rights”
        Castro did indeed infringe human rights as did many other countries. But he also did positive things which the usual human rights abusers did not do.
        What did the far right regimes in latin America so beloved of Thatcher and Reagan do for their citizens? Like Castro they killed their opponents ( in the case of right wing regimes through death squads)
        But did they provide universal education, healthcare and social services free at the point of delivery? Something that not even the US has yet quite achieved, though we have had it in the UK for some time, despite the actions of Thatcher to stop such services to citizens.
        Well did they? Nope not a bloody thing.
        But idiots like you never understood that. Castro had a lot to answer for, but he also took a poverty struck island from the hands of a dictator and the mafia and gave the citizens a basic level of care. That deserves some praise.

      • “you are obviously one of the political ignoramuses …”
        No Gareth. That’s you actually, and all your traitorous Lefty mates.
        Your Lefty friends such as Lenin, Stalin, Mao and Hitler – yes, HE WAS A SOCIALIST, no matter what you lying lot claim – killed several orders of magnitude more than any other political or religious ideology that has ever been.
        Margaret Thatcher rescued this country from the lunatic Left trade union thugs – motto: “We will bring the country to its knees” – and massively improved the exonomy for decades.
        Unlike you lot, she was a true patriot.
        Were you around in the 1960s and 1970s, terminating in the 1979 ‘Winter of Discontent’?
        I very much doubt it.

        • Reality check: “Gareth once again illustrates just how far one can stretch reality in an attempt to justify the unjustifiable.”
          That’s what Leftys do

    • Let’s not forget Che!, his brutal colleague.
      But, many people, mainly women, weeped when Stalin died.
      People are crazy.

  43. Maybe they could get the total weight down for backpackers. Twenty-five pounds seems like a lot to carry.

  44. Kenya is an oil rich state. This is proof of the adage about aid to Africa being a black hole for money and resources.
    “Aid is all about taking money from poor people in rich nations and giving it to rich people in poor countries.”.

  45. God…. certainly hope none of the Progressives that run California get wind of this. We will be mandated to buy them to light our houses. They will probably also mandate improvements to be made to the gravity power generators to power all the appliances and water heaters in our house as well By 2050 your house will have to be 100% gravity powered our you will be paying a $20000 fee.

  46. The climatocracy is less and less subtle in their arrogant and demeaning view of how those outside the climatocracy should live. The attitude expressed towards the poor by the climate obsessed deserves a third finger salute.

  47. I did better by modifying a foot pump to be a generator charging a conventional led lantern cheaply and readily available from camping stores in the same way the wind up ones work but foot power was capable of far greater capacity for less effort. I think it was 150 lumens as well ( I Cant’t be sure as the label print has worn off.)so it has a reasonable light level. The foot powered generator was made entirely from scrapped stuff and I saw enough for two fair sized villages in a single trip to the recycle centre.
    I did wonder about modifying one of those stepper exerciser things so you could do it while sitting down in an arm chair but never got round to it.

    • Why should the Kenyans be trapped at the equivalent of the kerosene lamp? Are they less worthy of the liberation of high quality, high quantity power than us in the West? It seems to me that only a bigoted misanthrope would answer on the affirmative

      • There is something to be said for working one’s way up. Americans didn’t go from kerosene lamps to 24/7 power in a week or a month or a year. Starting at the bottom allows people to work up slowly and adjust. It’s not keeping them trapped—thought that may be the goal of the greens—it’s realistically letting them grow and learn and move up.

        • Problem is the people of African countries should ALREADY have worked their way up to it. At the end of European Colonial rule most of them HAD productive industry and agriculture, they were already at and above the kerosene lamp level of technology.
          I keep asking this question, been asking for 30 years, and never get an answer. How many times do you have to tell people to boil their drinking water, do not urinate/defecate in springs/creeks/rivers/lakes? What is the magic number? Apparently we haven’t reached it, we have been telling them these things for nearly 200 years.

  48. will the world ever be rid of these crazy marxists ?
    pheeeew i cant believe enough people have awaken
    to give us another bite at the freedom apple

  49. Forrest Gardener — Remember Pet Rocks? When the fad passed stores were stuck with them. A little repackaging and they can clear their storerooms. Pet Rocks, now more than just a companion! They will bring light into your life! Etc, etc, etc.
    Eugene WR Gallun

  50. Andyj’s remark about aid is taking money from poor people in rich countries to give to rich people in poor countries is sadly so true far too often and excellently phrased.
    Can I just mention something to the gentleman who uses kerosene mantle lamps. Yes they are very bright indeed and surprisingly so compared to wick types, but this brightness is achieved by a reaction in the mantle using Thorium to achieve incandescence. In the process it seems that alpha particles are a by product. There are health warnings about not using them in confined spaces.
    I am not advocating using kerosene if electricity can be provided, but kerosene heating is efficient in cold climes and for cooking kerosene stoves are far better for health than dung fires.

  51. Dammit, I will repeat what i said up top. WINDUP WATCHES! There is a fortune to be made. We can get Al Gore in for a piece of the pie. Next speech he gives he dramatically pauses halfway through — and winds up his watch! What an impact! Greenies will be falling over each other to purchase the new green status symbol! A WINDUP WATCH!! We can go weird — windup Mickey Mouse watches! Go high end — the windup Rolex! There is a fortune to be made here!
    Eugene WR Gallun

  52. Having worked a lot in very poor parts of Africa, think this is a pretty good idea, but wonder how people whose job is picking up gravel off the road and selling it to the guys making concrete blocks will be able to afford this.

    • They state target costs of 5$. This is affordable in africa and an equal price to a kerosene Lamp.
      And best thing is to produce as much as possible of it in Africa.
      To donate something is a dumb thing. Make things simple and cheap and people will buy it, if they agree to the idea.

      • Agreed. You may have to donate a few to get things started, but figure out a way to involve the people in future production, and you have something going. It’s not charity that way and the people have a stake in it.

  53. In Laos the other day there was a shallow river which people had dammed with stones and rigged little homemade paddles generating a few volts for the kampong. Thick wires, less loss. Pathetic. They need a coal fired power station NOW.

  54. Children sitting next to a kerosene lamp for hours trying to study is not a great health benefit. The lamp may not have a poor light, but the light is infinitely better than a lamp when you have o money for oil. Instead of whining that it is not perfect, how about helping to develop the idea along with other idea for free lighting sources in poor countries Or are you worried about losing the excellent profit made on selling paraffin to poor nations?

    • Several people have already mentioned a better idea, Gareth; Solar/battery lights. I got some for 2$ apiece, and I’d rather have one of them than this intermittent contraption.

      • How long will battery of your 2$ Lamp last if used on a dayly base? I guess its finished before one year.
        And how many hours it will shine? In Africa sunset is nearly exact 6pm, so you need about five hours
        And how good is the light for working or studiying.
        I worked in Afica seven years as a development worker, and the battery has always been the most vulnerable part of solar lighting.

      • Johannes,
        Well of course they won’t last forever, but neither will that gravity powered one. Replacing the battery once a year would not cost much . .
        The brightness of mine seems to be about what this new thing is offering (dim), but mine are VERY small and cheap. I’m thinking it would be best to beef it up some, and design it for the specific use, and make the battery easy to replace.

      • Oh, and five hours (total, mine have an on/off switch) average per night doesn’t see unrealistic in the tropics given the sun is always high in the sky. More solar cell area, more charge and or brightness . . from my limited experience it seems a natural fit . .

  55. These are human powered lights. The need is based on the inventor’s question (from the video), “What do you do if you’re not going to store power?” Why aren’t you going to store power? Maybe the question should be what is the best way to replace kerosene as an energy source for light.
    There is already a supply chain for kerosene. People have the money to buy kerosene. How about using the existing supply chain and financial resources to distribute … batteries?
    The bottom line is that this may be a good idea but unless users are willing to pay for it instead of buying kerosene or batteries or hand cranked generators, it’s not a good idea. So far, throughout the world, chemistry has won out over muscle in the market for lighting the darkness.
    And finally, why is this better than the human-wound-spring-powered clockworks inside each all the “Big Ben” alarm clocks that were popular around the world for decades?

  56. There are a wide variety of wind-up lamps available on the market, from headlamps to flashlights (UK ‘torches’) to lanterns. Usable by people who can’t lift 12 Kg of rocks at one time. Many feature selectable light levels, and they last much longer than 20 minutes. One by C.Crane will power 15 LEDs for 5 hours on one winding (9 LEDs for 7 hours).
    GravityLight may prove to be the BetaMax of the portable lamp industry – badly timed, bad read of the market.

    • I did have a similar one as well as a wind up radio. neither lasted long, the winding arm breaks or the generator is not good quality. It’s a great idea though, and if they improve the quality I’d buy another one.

    • “Usable by people who can’t lift 12 Kg of rocks at one time.”
      Did anyone actually read the article? Eric certainly could have provided more information if he wasn’t so busy taking cheap shots a renewable energy. The new design incorporates a winch so that you don’t have to lift the whole weight in one go.

  57. If I was a contestant in a beauty pageant (I know, not gonna happen) my stock line would be, “I’d like to see safe, inexpensive, reliable, electricity to anyone who wants it.”

      • A decade ago I moved from Lower Manhattan to 2500m up in Teller County , CO . Now I’m aware of the phase of the Moon w/o thinking . But I am still amazed by the amount of light from Colorado Springs and even Denver .
        When I was at Northwestern , they had built an impressive observatory , , at the corner of their new Lake Michigan land fill . My immediate thought was what a stupid place to put an observatory ; pure show .

      • LEDs do not inherently cause or increase light pollution, any more than any other electric lamp technology does. Light pollution is caused by the choice of how much light and what wavelengths of light to produce. Those who replace non-LED lamps with LED lamps can use LED lighting to not change anything except for reducing electricity consumption, which has many benefits – even if manmade climate change is not a serious problem or significantly reduced by increasing the efficiency of lightbulbs.

  58. ..So how exactly does this cook their dinner ? Or will they be too tired, from gathering food and water all day and then continuously lifting 27lbs in the evening, to bother eating ?

  59. I would think that significant lifestyle improvement would require a “stack” of tech advances rather that isolated ones such as this gravity lamp.
    For instance, there are groups building efficient “rocket stoves” for folks who cook with wood/coal/dung and suffer from indoor air pollution and deforestation. These stoves have often been a hard sell. Now imagine such a stove with a built-in or detachable peltier generator which charges a capacitor or battery which then connects to a reading light after cooking is complete. That would be three “stones” stacked: cleaner cooking, micro electrical generation, and one micro-electric device. But that could be the foundation for many cheap follow-on devices. For example, even in the US I can buy a USB reading light for a dollar.

  60. I have a clock that works like that. And sure enough it keeps the clock ticking for about 24 hours. Then I have to pull down one of the weights to cycle it again. Think I’ll figure out how to hook up an LED light. Send money.

    • Thanks for the chuckle, we have one of those, the weights don’t go down anymore but the time is accurate twice/day. One needs to think long and hard as to why in 2016 some people in this world need to be relegated to such primitive and inadequate technology while those of us in other nations just need to get off our butt and turn on a switch.

  61. It is not the idea that is poor — it is the scale. But only if all that one wanted was light in the home in the evenings.
    This little light of theirs produces the same number of lumens (the measurement unit of luminous flux) as your average table candle (not a tea light candle, but a real taper) 12-15 lumens. I, for one, could not read or study under those low-light conditions, but it would be preferable to stumbling around in my shack-like home in the evening. We have spent many an evening sitting at a simple table under candle-light or kerosene lamp light eating dinner with families that could not really afford to feed us. (Most husbands never knew that I slipped their wives a $20 bill after the meal to make up for my offense.)
    However, the clockwork mechanism of this little clock is a real engineering workhorse, and suffices to take energy stored by raised weights, and allowing that energy to do work over a period of time.
    Apply this to the village water-well by building a water tank tower — tank on top — over the hand-pump well. Extend the output pipe of the well up to the tank. Install the clockwork under the tank, operating an oscillating arm that moves up and down three feet at each stroke, operating the pump. The clockwork is run by a 55 gallon drum filled with rocks or sand that is raised to the top each morning and evening by the cooperative effort of all the healthy adults pulling on a rope tug-a-war style. The resulting system provides running, pressurized water to the entire village in a low-tech, locally build-able, locally repairable system.
    Simple generators (using ubiquitous 12 VDC car generators) could power automotive light-bulbs (also ubiquitous) in every home of the village….with proper gearing … easily providing all the homes
    with light and cell-phone charging for four or five hours each evening — and the weights could be raised again in the morning providing another period of power.
    Simple, time-tested OLD technologies, that rely on locally available resources, including human strength, can be used to bring modern advantages to rural locations.
    These over-engineered solutions — like the panel-battery-LED give-aways — are solving the wrong problem. The people need electricity to run refrigeration and the machines that make micro-businesses possible, Such power needs to be at the very least dependable — even if just 8 hours a day — so that food can be preserved and safe and businesses can operate and produce needed things and services for sale.
    All of the thought, effort, and money being put into these “neat-but-silly” solutions, which their inventors and promoters would never consider suitable for their own homes in a million years, ought to be going towards the construction of locally-feasible and maintainable electrical grids, powered by whatever the locals have to offer — micro- and small-hydro, small steam-generation burning waste, human-power, mini-solar-farms. In all the areas I have worked, the locals people would gladly have exchanged an hour’s work a day for dependable electrical power.

    • Few people are aware of the power of cheap power.
      A machine which is about 75% efficient produces one horsepower for each kilowatt of input. One horsepower equals 550 pounds of weight lifted one foot every second. Or more than 3 of those 60 pound bales lifted 3 feet every second, 180 per minute, about 11,000 per hour. Cheap electricity is an amazing productivity multiplier.

    • A small coal fired plant would provide a lot of villages with all the power they need to actually live, AND supply jobs mining the coal AND supply energy for small factories, thus creating a cash flow into the area…Oh wait..that is Capitalism, the “Watermelons” will have none of that ! The liberal left KNOWS what is best for the poor of Africa and the world, just like they do in Detroit…

  62. I’ll be the goat to say I think this is a pretty good idea. I don’t understand all the sneering.
    There’s plenty of silliness that comes out of the AGW crowd, and Worrell does a great job of exposing it. This time however (and it’s the first time in my reading) Eric swung and missed.
    Indeed, this idea should be developed further so that the system runs for hours rather than 20 minutes between need for lifting, and is much brighter. While to a modern western person it seems rather silly to have to lift 100-200kg of rocks/bricks/whatever every few hours to have lighting, it would be miraculous to people without lights at all.

      • @rovingbroker good point, although I still think a gravity light has some attraction over kerosene lamps (nothing to do with AGW idiocy, rather simply the stuffs nasty and messy).

    • Why is this a questionable idea? Because there have to be better ways, even in Africa, to make electricity than pulling a heavy bag of rocks up every 20 minutes to get light. It’s a cutesy, not well-thought-out idea that I cannot see selling to the African people. I’m sure they have better things to do than lift rocks every 20 minutes. They might even be insulted.

    • ..Just think, if YOU or anyone else here, had the money that Bill Gates, Warren Buffet and George Soros have , how much good could you actually do for ALL the poor, not just in the U.S., but in the world…As the great man said…”It’s jobs stupid” …OK, I am giving myself a time out ! This silly crap gets me angry…They are simply hypocrites !… IMHO…

  63. My grandfather used to have a magnificent gravity clock, although it was never called that way. It was a pendulum clock and it enthralled me. It only needed to be winded up once a week, the weight was much lighter than 27 lbs.
    That said, this gravity light has a 15 lm luminous flux, basically the same as a candle has. A kerosene lamp has much higher light output. And you have to lift the weight about three hundred times to get the same amount of light as by burning a liter of kerosene.
    What is more, price of GravityLight is $70, while you can get a kerosene lamp for ten bucks. A liter of kerosene is about 75 ¢ and the thing is up to 8 times brighter, than this gravity hack.
    Eight GravityLight costs $560 and you have to lift weight for them 24 times in an hour. That’s a full time job, so you need a slave to keep wages down. But that’s illegal and rightly so.
    Awful deal.

    • For $70 in Zambia (~700 kwacha), unfortunately, the best use of these gravity lamps would be as paperweights for the Lungu administration’s bureaucrats. I hadn’t realized they were so expensive. At $7, they might have made sense as freebies from the West. A poor person might have been able to purchase one at 70 cents (competing with food and clothes for priority).

      • Yes. And you’ll have to lift your ass three times in an hour, which weighs considerably more than 27.5 pounds, to have your candle light running. Energy is kinda conserved, so you can never get it for free. You need to purchase, eat and burn some extra food to be able to do that exercise, which costs money and is associated with carbon dioxide emissions much higher than burning kerosene due to the extremely low energy efficiency of processes involved.
        Silly idea, anyway.

  64. This reminds me of the history channel series on the men who built America with electricity, steel , railroads, and petroleum fuels.
    Absent the contribution of these titans it is speculation as to where we would be today. This is an excellent documentary of how these men (Rockefeller, Ford, Vanderbilt, Carnegie, Morgan) in competition moved the US and ultimately from the darkness of candles and whale oil into the modern age we enjoy today. Part of the story includes how Rockefeller dominated and distributed kerosene to the masses who could not afford whale oil for lighting. Later upon the advent of electricity, Rockefeller saw the demise of his kerosene business developed gasoline as a fuel revolutionizing auto transportation.
    The average person has no idea where we might be absent a system that allowed these titans to make the world a better place to live, while they became rich and wealthy themselves.

    • ..Most College graduates today have no idea what surviving in the “Real World” means, never mind surviving in the depths of Africa…Why not ASK the Africans what they need or require ? Show them the options and then let THEM decide ? Isn’t that called …FREEDOM ?

      • Excellent idea. Take in a bunch of options and see what the actual users like. Kind of like a focus group here……Not really. Just wanted to see if you were paying attention! Still, marketing research does have it’s place.

    • ..Hey, it only cost $5.000,000, so far, of her supporters money, for her GREEN stupidity !! Liberals and Greens have no problem spending OPM ! ( I assume I do not have to define OPM to most commenters… here)…IMHO….

      • You know that a BOT filled her coffer to the tune of a steady $160k per hour, including the wee hours of the night? This money mostly came from a source other than her supporters. Think in the direction of the Soros “family”.

      • You realize that her coffer was filled by a BOT at a rate of $160k per hour, including the wee hours of the night so as to meet the Wisconsin deadline? This was mostly not her supporters, but a organization. Likely with a puppet master such as Soros at the end of the string.

    • Actually, run the electric output from one of those into a set of batteries then draw current for use from them. Almost like something that has already been done, only it has been! 😉

  65. I think that I would quickly supersede this invention and replace it with a treadmill wheel powered by a flock of white mice pursued by a trained cat. Even a battery linked exercise bicycle would be more fun.

  66. Think of all that energy packed in a 28 lb bag of rocks at 5 feet above the floor.
    It is 0.18 BTU’s, WOW.
    Now a gallon of Kerosene has 134,000 BUT of energy and weighs 6.75 Lbs.
    So 1 gallon of Kerosene has 744817.6809 times as much energy, or put another way the a child would have to winch up the bag of rocks 744,817 times to get the same amount of energy as from a kerosene lantern with one gallon. (not including any relative inefficiencies)
    Wouldn’t the child be better off spending the time reading rather than winching up a bag of rocks?
    Please somebody tell me I made a math error somewhere?
    Besides one cannot easily hang 28 lbs from a wall?

    • It seem as though the Progressive elites are so guilty about letting the developing nations use fossil fuels, they become irrational about understanding how degrading it is to deny others access to useful energy while they jetset around the world wily nilly keeping multiple mansions wasting energy.
      I always say you go first, the elites should get off the grid and read with the “rock” powered generator getting up and winching the rock bag themselves for a few years

  67. Now, really want to help people in under-developed counties, really? Transport AND a source of electricity for charging electric storage/use type devices. Oop, there it is.

  68. We seem to have lost focus, in all this argy-bargy, on the stark split between producing energy by anthropogenic means (including trained mice, horses, buffaloes, etc.,) and that produced by perhaps the greatest breakthrough of all — the harnessing of fuel to create heat-engines and Power.
    The advance of less-developed tribes/nations/cultures is axiomatically circumscribed by the limitations of “Horse-power”, “Man-Power”, “Child-Power”, etc. PERIOD!
    The impoverished billions of less-developed peoples need CHEAP SOURCES OF ENERGY to lift themselves from poverty … just as we did in the Industrial Revolution. For anyone to argue that THIS IS NOT THEIR RIGHT is beyond my comprehension of civilized, empathetic, progressive thinking.
    So, if Kenya is sitting on a pile of coal, and if coal is the lowest-cost source of energy, let ’em go to it, exploit it, advance their economy, and advance (and welcome) their progress, bringing all the fruits to them that we have taken for granted for the last 2 generations (e.g., laundry & dish-washing-machines ; refrigeration, etc.)

  69. great idea. i’m gonna start a kickstarter campaign to raise funds to develop the “gravity powered hello kitty vibrator”….wanna sign up?

  70. this (ridicule) post was no good one and the forum an echo chamber for poeple not understanding how life in rural Africa is. Vera often no cash availble / only after harvest, Mile away from a store. Expensive kerosene.
    And some guys talk about cheap coal power or diesel engines! Buy these from 20-50$ per month or 100$ per year after harvest….A family need ligth now, not in 20 or fifty years, when electric supply is finally there.
    The alternatve to move to the slums of big cities with electric suppply, but earning money through prositution, illegal work and crime.
    Having a light in the evening may be a part to keep them there. And about fiftenn lumen as compared to a candle:
    If you direct them with an angel of 60 or 45° toward a table, you get a 10 brighter light there compared to the 360° of a candle.

    • Any idea is not better than no idea when it’s the wrong idea.
      (In plainer terms, throwing in any old idea and trying to say it helps is not good if it doesn’t help. Has anyone actually taken these to Africa and tested the idea large scale? Cook stoves were a hard sell. Old ways resist change and this is a huge change.)

      • RC? In the late ’80s I did time in central africa. Yea, people got no real concept, that has changed a bit, with so many Americans having been exposed to the middle east during the last 15 years. Still, we are all able to come back to The World. I have lived without running water and spotty/unreliable electricity right here in CONUS so I feel for them. All the same they got to fix their problems.

  71. It’s good to see that some commenters are well aware of both the expense and safety hazards posed by kerosene lamps. (see details at: Many children are burned each year by kerosene lamps and candles. Even dwellings are burned accidentally. When I was young, my sister’s hair caught fire when she was reading by candle light. Much safer are a number of solar powered lighting devices that have become increasingly available in regions without electricity, but these are not necessarily cheap. My phone, iPad and three cameras are powered by a 20-watt solar panel that charges a lithium power pack. Total cost is more than $100. A 100-watt panel and a much bigger power pack can power my laptop. Cost exceeds $400. Cheaper systems that power only a single white LED lamp can be found online.

    • Forrest and Johannes
      Ai agree about the risks averted and the superiority of the high tech solutions. I was just handed as a memento a solar powered key fob that has two high intensity LEDs. It is made by Poly Solar, a company in Beijing. It has three small batteries in it. It is somewhat like a garden light in that it has a small solar panel on one side and an LED switch. It is far brighter than a garden lamp.
      In Africa it has been shown that when students have light after sundown they study about 2 hours more per day.
      LEDs are one invention that really transforms lives. Like the cell phone, it greatly reduces costs, saves lives and makes people happy.

  72. especially since LEDs put out so much light nowadays.

    A single bright while LED draws about 3 watts. Several are used to make an LED lightbulb.
    You’d need to put about 30 GravityLights together to power that LED.

  73. “Corruption” is a term bandied-around so often that it has lost its bite.
    We need a refresher, as a large % of readers have no clue of the obstacles to getting 1st. World money to 3rd. World recipients.
    It is a beautiful, and eminently sellable Charity-concept in principle but the reality of getting most (any?) of it to the village-leaders is another matter.
    Just as emergency food supplies are ‘taxed’ at successive road-blocks between (air)port and village, so does cash transfers. MOney sent for funding water-wells, or buying diesel-gen-sets will get there — if the recipients are lucky — at cents in the $.
    To say nothing on the tax imposed on the importation of foreign manufactured goods, administerd by ….. ? guess who??
    I’m just mentioning this ‘cos this wd seem to be the reality of altruistically trying to help peasants in 3rd. W. couhtries. The crooks get their substantive cut first …. coming & going.
    I wish I had answers ……. Any thoughts?

  74. Sounds great for those who want to get off the power grid. How much weight would be required to provide power to the typical window air conditioner for an hour of a typical frig for a day. or to cook dinner? What would be the cost of these power units on a KW basis?

    • You want a kilowatt? The device in this article is .085 Watts. A kilowatt 24/7 using this technology would need a team of two horses on a treadmill. They can probably work at that rate for 4 hours, so you need 6 teams of 2 to get 24 hour power. That’s 12 horses. Then add the full-time horse minders, the horse feed, shelter, and disposal of waste from 12 horses. Call it 4 people full time needed to support the horses.
      Or you could buy a 1.6 KW generator that uses 1.1 liter/hour to fuel. But that uses evil petroleum fuel and we can’t allow that.
      I, for one, am extremely grateful that I can flip a switch and get a kilowatt whenever I want it. I am also grateful that I live where my government doesn’t prevent me from using that kilowatt. (California was heading in that direction though) I have also installed an off-grid power system using a small PV array, a forklift battery and a 1.2 KW sine wave inverter. It was FAR more expensive than grid power but there was no grid where I needed it.

      • Real horse power, that’s the ticket. I live in California. To not be cruel to animals, the state should mandate i acre per horse and at least every other day each hourse should be pastured. All of the hourse’s food must come from pasture land maintained by each household. So California should mandate that each household maintain a minimum of 24 hourses for power and 25 acres of pasture land to support the 24 hourses.. California will have to very significantly lower its population to make that happen. In my case, the state needs to come on and get rid of most of my neighbours and to convert their homes and access roads into 25 acres of pasture land to be added to my property and facilities, like a barn and stable to support the horses. I am poor so the state needs to provide personel to take care of the horses and to run the 1kw hourse actuated power system. The state needs to do this for every poor person like me that decides to remain in California. I also want the state to provide me with an all electric car and a roof top solar charging system to charge the car and to provide additional energy for my home so I can cook, run a refrigerator and on occasion warm and or cool my home. The solar energy system must be such that it works off grid and has sufficient energy storage capacity, The solar energy system must also be suplemented with a wind energy system. I am poor and cannot afford to pay anything for such a system but all equipment installed on my property I must own free and clear and without any negative tax consequences. I am willing to do my part and allow such changes to my property but the state must first do their part and provide what I request and without raising by taxes.
        It is great that your have done well moving away from California but i still live here and cannot move away from the costal zone where I live due to asthma and alergy problems. I also need the state to come and build at least a hundred foot sea wall to protect my property from sea level rise and from possible title waves and storm surges. The seawall will have to be built form Corona Del Mar to Palos Verdes and provide protection for all harbors and boating facilities in the area. I also want the State to provide a hign speed rail station within walking distance from my home and another station within walking distance of my daughter’s home in Northern California so I can visit her anytime I want and not have to use my car. Since I am poor the state will have to provide me with a pass that will allow me to ride the high speed rail system anytime, free of charge. I am not asking for much.

  75. Stupid concept. Just throw some NiMH cells in and hand crank generator, and you can have hours of light without recharging. Can also use solar to charge during the daytime.

  76. Greenies always ask me how long it takes me to recharge my Smart car. “Usually about 3 to 5 minutes.”, I respond, casually. Then, they want to know how far it will go on a charge. “About 400 miles at 70 mph.”, I again calmly explain, which seems to mystify them. They rarely begin the asking with, “Is it electric?”, which ruins my joke. Some call me a liar. Some shake their heads and simply walk away as I must be crazy. My Smart runs on gas….(c;]

    • Larry, I always park in spaces with signs for “energy efficient” vehicles. When questioned I respond”I efficiently put gas in the tank and it then is efficiently burned so I can efficiently drive where I am going”. Leaves them sputtering every time. The “Pork Eating Infidel” and “All out of F*cks to Give” bumper stickers really should clue them in.

  77. So, this is intended to be used in a poor country. The weight to be used is rocks, which are easily available. That makes sense. The maximum loading of rocks, for this light, is 12 kg. Since this is a poor country, how do they weigh out the rocks? Is there a scale built-in to the light? How much does it degrade the mechanism, to put too much weight on it? How easily can the gears be stripped out? If there is a lot of dust in the air, does that affect the mechanism? Has this been field-tested for several years, or merely assembled in a pristine laboratory?

  78. eliminating the kerosene lamp is a great idea – kerosene is expensive, taking a high proportion of incomes in developing countries and contributing to fuel poverty…. it is also a health hazard and safety risk.
    but the solution is already being rolled out throughout Africa and Asia – commercially sold solar LED lamps (with mobile phone chargers)
    (many other examples)
    Or you can go one stage further with solar home systems and other improvements:
    I’ve often suggested LED lights for the developing world in these columns – and have been roundly criticised for it…
    Strange that this seems acceptable so long as the word ‘solar’ is not attached to the light…

    • As long as the LEDs are made in China, or someplace like that, I’m fine with LEDs. The process for making them is quite dirty and nasty. That was the big advantage to incandescent bulbs, they were relatively clean to make. Of course, the big problem with an LED is making sure the resistor/LED combination is balanced, or else the LED will blow if there is a spike in the current. Companies cut costs by using one resistor for a group of LEDs, and that just means the whole group will be taken out at the same time. I have some light panels that have hundreds of LEDs, but they are in groups of 8, attached to a resistor. Over time, I have watched the panels slowly darken, as groups of 8 stop working.

  79. I think it is a great idea! I’d love to use it as the power source for my son’s computer when he’s playing video games.

    • Giving them sh*t that does not help is sh*t that does not help them. Period. Full stop. Want to help them? Kill the f*cking socialists.

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