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LEDs Lighting Up the African Darkness
Peace Corps Online writes "In a non-electrified society, life is defined by the sun and little is accomplished once it sets around 6 pm. Only 19 percent of rural areas in Ghana have electricity. The rest use foul-smelling kerosene lamps to light their huts, which pollute, provide little light and are major fire hazards. But now Philips has partnered with KITE, a not-for-profit Ghanaian organization, to bring artificial light to villages that have no electricity. The new Philips products include a portable lantern which provides bright white light where it is needed, the Dynamo Multi LED self-powered (wind-up) flashlight that provides 17 minutes of light from two minutes hand winding, and the 'My Reading Light,' which is a solar-powered reading light with built-in rechargeable battery. 'People can now do things in the evening,' says Harriette Amissah-Arthur, KITE's director. 'If you could only see the joy these products bring the villagers. You look at their faces; you have to see it to believe it.'"
This isn't the first product Philips have produced for developing countries.
See wood-burning stove: http://www.research.philips.com/newscenter/archive/2006/060227-woodstove.html
I wish they would make them available to buy in the developed world though. I'd love some of this gear for outdoor pursuits.
A small price to pay for not being eaten by a Grue.
Village idiot in some extremely smart villages.
This article is biased towards Phillips' contribution... Shouldn't there at least have been a mention of the "Light Up the World Foundation" and Dave Irvine-Halliday (U of Calgary)?
http://www.ucalgary.ca/oncampus/weekly/nov4-05/schulich-lutw.html
http://www.google.com/search?q=philips+lutw
This game will waste your life. Don't clicky!
The EU has done no such thing. Yes, it banned the sale of classic lightbulbs (effective September 2012). But what you replace them with is your own choice, you are not forced into buying fluorescent tubes.
The mercury problem is easily solvable. Just institute a deposit recycling system for the fluorescents, like there exists for bottles in many countries.
By the way, am I the only one to find the light from white LEDs irritating? Somehow I find it harder to see in LED light than with alternatives, even when the light output is theoretically comparable. It is as if the frequencies in its spectrum just miss the the ones my photoreceptors are tuned into...
I am the only one who thinks kerosene lamps actually do smell quite nice.
- Raynet --> .
So Philips is the agent of the Devil?
think of this:
"In an electrified society, life is defined by the television and little is accomplished once it starts around 6 pm".
Philips makes lots of TVs too.... case proven :)
It is as if the frequencies in its spectrum just miss the the ones my photoreceptors are tuned into...
:-)
Well, that's because the LEDs actually are missing (large) components of the spectrum!
Even when your eyes are tricked into believing the light is white (by equally stimuling the three kinds of color-sensitive cells), the light reflected off of objects isn't "correct".
Imagine two green objects. One has true green pigment, the other has a mixture of yellow and blue pigment. Both look the same under incandescent light, because the light from a glowing filament emits a full spectrum .
When an LED doesn't emit a full spectrum the two objects don't like alike. The "true" green objects only reflects "true" green, not yellow + blue. The "yellow + blue" object doesn't reflect "true" green.
That's why it's hard to see in such light.
Your eyes (or brain) can adapt very well to changes in color temperature (yellowy incandescent light, or the blueish halogen light), but it can't cope with holes in the spectrum.
This goes for compact fluorescent lights as well, even as they keep getting better. The cheap ones are really crappy in this respect.
For fluorescent tubes there is a rating for color temperate and color rendition. It isn't used (as far as I know) for compact fluorescents as they score way to low on this scale. That would make the public relations department of the manufacturers unhappy.
I modded you funny, but I am at this moment in Africa and it is true that such light (or modern technology) in a tent for example, can indeed attract freelancing bandits.
According to wikipedia ... assuming a coal fired plant this statement is correct - the total amount of mercury is lesser when using a CFL:
"The rest use foul-smelling kerosene lamps to light their huts, which pollute, provide little light and are major fire hazards."
In other words, the exact same type of lighting my grandfather's household relied on when he was a child. It's easy to forget that there are many people alive today that only had access to very primitive technology when they were young. And it wasn't because they couldn't afford it, but because it didn't exist anywhere on earth.
While I am sympathetic to the plight of countries that cannot afford modern technology for their entire population, and the massive infrastructure required to support it, I do keep in mind that we are talking about a gap of only a few generations - not centuries or millenia.
Better known as 318230.
My own experiments, years ago, showed that in real world use CFLs are equivalent to about four times the wattage of standard 1000 hour incandescents, whereas full size fluorescents produce maybe 5 times the output of the same wattage incandescent. Linear 8W CFLs as used on boats and caravans give about the same actual illumination as a 20W tungsten-halogen bulb, because their light output is much less directional, but then they are much better at illuminating dark corners.
Case in point: when we moved to our present house, the kitchen used 3 100W bulbs. These have been satisfactorily replaced with 3 20W CFLs for the last 20 years. As different types of CFL have evolved, there has been no deterioration in light output, though it is important to buy good quality - GE or Philips - bulbs.
I note that the cost of LEDS is now becoming comparable in lifetime cost with CFLs. The main issue is that LED drivers are relatively inefficient because most of them waste a lot of power in series resistors. What is needed is a really efficient current driver IC for LEDs. This would drive up the efficiency of conversion and make them even more useful in the Third World.
From scarped cliff or quarried stone she cries "A thousand types are gone, I care for nothing, no not one."
Why doesn't it just tax them at a higher rate?
As big a fan of CFLs as I am (my house lighting is 99% CFL), banning incandescents is stupid. What do you use in the oven? CFLs NOR LEDs can withstand the heat. (Then there is the dryer and freezer, although leds might do the job, CFLs won't fare well there).
My Reading Light? I'm getting annoyed with people naming everything "My xxx". Was this started by Windows? Or was it "My Little Pony". My God. These people should hire some open source developers to name their products.
He's probably in the Congo.
Ghana is actually one of the most stable countries in Africa. One that has just finished it's third General Election (with universal suffrage too) this year. It's first was in 1992, with 1996 letting the same guy in again. But considering it spent most of the 20th century ruled by a military Junta, it's come along way.
It pays to be obvious, especially if you have a reputation for being subtle.
The Dulux series by Osram is marked with color temperature and CRI in one number: An 827 CFL is a 2700K light with a color rendering index >80. Osram makes compact 930 lights (CRI>90 3000K), but not (yet) in the "normal" E27 socket format. Consumers looking to replace incandescent bulbs should go for 827 CFLs, as they're the drop-in replacement with a light color and color rendering quality closest to incandescent bulbs. ("Daylight" and other color temperatures >3000K are what most people associate with sterile, cold fluorescent tube light. 2700K is the "warm" yellowish light they're used to from incandescent bulbs.)
banning incandescents is stupid. What do you use in the oven?
Indeed! Neither CFLs nor LEDs give off enough heat to work in an oven.
When our name is on the back of your car, we're behind you all the way!
I have an LED headlight for my bicycle.. its very bright .. and very expensive .. it cost $200, and its the cheapest way to obtain safe night-riding ability.
and ive never ever noticed any weirdness to its color spectrum .. Of course, at night one is not looking for incorrect color rendition .. nonetheless, it works, it makes night into day, it keeps me alive... and for those advantages, its priceless.
tkjtkj@gmail.com
"There are 11 kinds of people: those who know binary, those who don't, and those who could not care less!"
'If you could only see the joy these products bring the villagers. You look at their faces; you have to see it to believe it.'
I bet their eyes light up!
"Congratulations, Boots. Your robot has become self-aware. You're a daddy now." -- Dr. Rho Bowman
Halogen light bulbs use tungsten filaments, JUST LIKE ORDINARY BULBS.
Two main differences:
- The filament is run at a much higher temperature, resulting in higher efficiency (around 20%).
- The gas inside the quartz "bulb" (the inner bulb, if you're buying a large bulb as a replacement) is a halogen gas (thus the name). These molecules combine with tungsten evaporated from the filament and effectively redeposits the tungsten on the filament. This results in longer lifetime.
End result: Longer lasting bulb, higher efficiency, roughly same environmental impact as normal bulb during production and disposal, still incandescent light (so no gaps in the output spectrum).
The one downside to halogen bulbs is that they get a lot hotter. Why? They have lower heat output, right? Yes, they do, but the AREA is a lot smaller due to the close proximity of the quartz. An outer bulb, such as typically present in a large-format "normal bulb replacement" (E26 base in the US), reduces this problem to about the same as for an ordinary bulb.
I spent some time in northern Sudan as a child. We had kerosine lamps that used wicks, and Petromax pressure lamps that used a mantle (like the Coleman lamps in the USA). As an 8-year-old I loved having my own kerosine lamp to read by in bed. Yeah, it was dim -- but in a pitch black room with dark-adapted eyes, it was plenty.
They DO pollute, they ARE a fire hazard... but the world will be a little poorer when the last kerosine lamp is gone.
I piss off bigots.
It is utterly typical africa==bandits US groupthink that got your "tech in Africa means you get robbed" got modded up.
Utterly typical non-US groupthink that everyone in the US thinks alike. The US is a pretty big country.
Infuriate left and right
It is as if the frequencies in its spectrum just miss the the ones my photoreceptors are tuned into...
Well, that's because the LEDs actually are missing (large) components of the spectrum! :-)
Even when your eyes are tricked into believing the light is white (by equally stimuling the three kinds of color-sensitive cells), the light reflected off of objects isn't "correct". Imagine two green objects. One has true green pigment, the other has a mixture of yellow and blue pigment. Both look the same under incandescent light, because the light from a glowing filament emits a full spectrum .
No!
Incandescent light is extremely blue deficient. It's not at all "full spectrum".
Colors look approximately right under incandescent illumination because your eyes are extremely good at color-adjusting the signal to the brain to compensate for the ambient light, and "most" things you tend to look at don't have sharp spectral bands. But in the case you describe, where a green color is synthesized from a blue and a yellow reflectance band, it will look very different under sunlight and incandescent light. (Look up "alexandrite", for example)
http://www.geoffreylandis.com
The OLPC was justified on a purely financial basis. The OLPC replaced heavy physical textbooks which require expensive physical distribution with one time laptop physical distribution and then electronic distribution of textbooks. Furthermore, in addition to the financial win, the textbooks could be updated with no distribution costs, they could be in the native language, and the students no longer had to carry all those heavy textbooks on their miles long walks to school; they had all their textbooks in one container, lightweight, with them at home and at school.
Regardless of how incompetent the OLPC management was, the laptop itself was fully justified on the financial basis alone, and the side benefits were a tremendous side benefit.
Infuriate left and right
Birds have a 4-color system, the last I heard; mammals lost theirs when they became nocturnal, and we have not fully recovered ours because, basically, primate evolution has not had long enough for it to reappear- perhaps the selection pressure is not that great.)
Actually some humans (and presumably, other primates) do have a 4-color system. It tends to occur more frequently (but still rarely overall) in females than males, perhaps for the same reasons that color-blindness tends to be more frequent in males. If I recall correctly the extra receptor is toward the violet end, and to these people indigo is actually a different color rather than just a shade of blue.
(Compare with mantis shrimp that have 12 color channels, extending into the ultra-violet and infra-red, plus receptors to distinguish circularly polarized light.)
-- Alastair
You need to count the sunlight that gets spread out by the atmosphere, making that lovely blue sky. Add up the blue sky and the yellow-looking Sun, and you get a bluish-white light.
The result is that natural shadows have a bluish cast. People look more natural outdoors because the shadows of their face get this.
To reproduce, method 1:
Cover your ceiling with an array of colored LEDs that point down. Focus the red and green ones to a 1-degree angle. Spread out the blue ones. Of course, this requires about a million LEDs for a typical room.
To reproduce, method 2:
Get a very high ceiling with bluish-white lights way up high. (mercury, halogen, LED, etc.) Focus the lights into 1-degree downward beams. At a normal ceiling height, add a false ceiling made from aerogel. (possibly with glass to support it) The aerogel acts like atmosphere, spreading the blue more than the red and green.
To reproduce, method 3:
Split the light with a prism, then put it back together without the blue. A couple custom plastic parts over a white LED should do the job. The blue is allowed to leak out the side, unfocused.