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.
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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?
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.
Political stability is the problem.
Figure that one out.
” 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.
I don’t see this supplanting candles and lamps. Too inconvenient.
And we are not going back to the 1600’s or any other time. They desperately need to exit the Stone Age.
It’s up to Africans to solve their many political and economic problems.
+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.
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.
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”.
I want the rock concession, John.
Then they would have accomplished something worth doing.
Just gotta love it. A “hi-tech” candle! Whatta they think of next?
A clockwork watermelon.
LOL-You just caused that “singin’ in the rain” scene to flash through my head.
Sunbeams from cucumbers.
Why not just give them those flashlights with the spin handle? Several hours charge with 30 seconds of spinning.
Way brighter too.
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.
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$, if you were employed. Many are not.
Kerosene Lamps produce smelly gasses which are not healthy. At night you have to close the door and windows because of moskitos. And evne in Africa it’s cold, so it seems there is som impact on health.
LED light with 15 lumen you can direct to a table or desk and this is much brighter on that area than a kerosene lamp. If you direct the light with a small angle, its multiple times brighter than 360° surround of a kerosene lamp.
If you have such a lamp, you never have to spend money on kerosene. So it depends on the price of the gadget.
I agree, it is likely a great fix if you can buy it for a dollar and it lasts for years. I recall a visit to a village where there simply was no light for most. This could be a real godsend to them. The negative comments here come from people who live a life of Kings by comparison, and so they simply have no idea. A bit of Christian humility is due IMO.
Even 20$ is not bad. People who use kerosene need more than one litre per week, so it is paid off after ten weeks.
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.
Let’s not forget why they are poor.
Clean up the corruption and things will get much better.
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.
I have one also. From South Africa. Good for hurricane country.
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.
How about a bag of U.N. Bureaucrats think of the potential. Wieght and hot air.
Brilliant idea, Logo!
The benefits go on and on.
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.
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).
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.
Or use a kid. Billy, it’s your turn to grab the rope and hang on for 20 minutes.
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..
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.
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.
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.
What brand bicycle do you use?
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.
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.
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.
A chance to get an education and really big muscles.
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!
Didn’t they try that with exercise bikes?
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.
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.
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!”
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.