Probably you've never seen a slum, so let me explain:
- Houses are juxtaposed to each other, there's no room for windows
- Roofs are corrugated, so you can't easily fit a top glass panel even if you have the money for one.
- There are transparent, fiber glass roofs, and some people use those, but often they don't get to choose the materials used to build the house, just use what is available.
So this is a quite nice hack that works for most houses.
I'm not sure that's fair. It is bulb shape and it emits light. The source of the light happens to be the sun. This is kind of like saying that tungsten lamps aren't lightbulbs because they don't work when not supplied with electricity. They're truly acting as a substitute by spreading light around a darkened area.
They actually -are- a substitute for the lightbulb they would otherwise have to be using during the daytime. It's just not a substitute for the lightbulb at night.
May not be true of what passes for slums in the US, but in other countries the next house in a slum begins where the current one ends. With hardly any windows to let natural light in, the indoors are quite dark even during the day. So yes, while it might not work at night unless there is a strong source of light such as streetlights nearby, it certainly does offer visual comfort during the day.
These bottles refract light thus illuminating a larger area. A skylight primarily lights the area underneath. Also, these bottles are less likely to break in a storm.
The title of this article bothers me since the article focuses much more on the bottle and light and rather than how poor and proud Alfredo Moser is. Regardless, pretty cool exposure of life in the slums, I'd bet there are more 'hacks' as a means of survival that are necessary there, but we wouldn't think twice about.
I will say the article is good, just don't like the title.
I can understand being proud of a beneficial invention and offering something to people without taking money for it. He's done an amazing good deed and hopefully will be remembered for this. But I don't understand the title of the article because I think taking pride in poverty is a weird position to be taking. The headline might just be catchy click bait.
>But I don't understand the title of the article because I think taking pride in poverty is a weird position to be taking.
Weird? It's one of the constant positions on poverty since the dawn of civilization -- from christianity and buddhism (the original, not the watered down California style) to bohemianism, communism and so on. Including the "proud, hardworking people" in most rural communities, etc.
Likely it's a compensation mechanism to protect the ego. I've been both rich and poor, and while extreme wealth is also unnatural, there is little that poverty has to recommend it.
I don't think it's a compensation mechanism. For some maybe.
But a lot of people had tons of money and got rid of them to be poor(er) and win some kind of freedom or normalcy that was important for them. Some did it directly, some did it through drugs, alcohol and extreme spending that showed that they didn't value the money at all.
I know a couple of people from rich families that ended up as austere monks, living in a monastery in my country. And people like Witgenstein (huge fortune, left it behind), Burroughs (of the "adding machine" family), etc.
Sorry, but wealthy people choosing to live austerely for spiritual reasons is not the same thing as poverty. Poverty is spending every waking hour worrying about money for rent and food, having no access to a doctor when you're sick, etc. There is nothing virtuous or meaningful about it, and it's certainly not something to be proud of.
Not paying taxes into NSA surveillance/military state or any whatever exploitive capitalism as other collared proles. Some people are far too busy than to concern themselves with financial vanity and the distractions that follow it.
Teeming masses of slum youth with linux netbooks must be high on the list of Fort Meade's threat matrix.
* You can be proud of opposing the NSA and the MIC and other mechanisms of destruction without volunteering for a life of destitution.
* You're free to do whatever you want, but I don't think that embracing poverty is a good solution to the NSA or the MIC. Mass poverty means that the government controls everybody's means of survival (foodstamps, healthcare, etc) which equals total political control. I think that creating business solutions and voluntary organizations that oppose these things is a more viable path, and having money helps with that. Start up a secure email webservice. Startup a charity organization that can help bring relief and attention to innocent civilians being bombed or harmed by governments.
* Your stance on capitalism being exploitative is a logical contradiction. A voluntary transaction can only occur in a market when both sides of a trade value what they are getting more than what they are giving up.
* What we have today as an economic system is not capitalism - governments dictate the winners and losers in the marketplace and those companies with the best lobbyists always win rather than the companies who create the most value for customers.
* You don't need to be a collared prole, to use your terminology. Software is all free and open source now. Start a business with some friends and live an alternative lifestyle to being a 9-5 corporate man. That's what a lot of people here currently do or are working towards.
* Not being poor doesn't automatically equate to financial vanity.
Interestingly, the link from the BBC News main page under the Most Shared and Most Read tabs has the title as "The light inventor who is poor but proud" which seems far more appropriate than the one on the article.
Although the initial cost may be prohibitive for the poverty stricken, it may be well within the acceptable price range for many others, and the gravity light has the added bonus of not requiring any fuel, nor does it require punching holes in one's roof.
Lights are used indoors all day long in much of the world. If you don't like poking holes in your roof, then you probably don't like sun windows either.
The gravity light requires manual labor to produce light, has moving parts that are more likely to fail, is more costly, and produces less light.
The gravity light produces a shamefully small amount of power - about 100 mW ("one deciwatt") by the manufacturer's own measurement. Even given the increased efficiency of LEDs, the illumination provided by one of these "bottle lights" is still about 100x greater, it's basically free, and it doesn't require you to tend to it every 15 - 30 minutes.
> I never needed indoor lighting during daylight hours
The way I figure, people in need of one of these lights probably won't have windows to let light into their homes, so it makes a bit more sense for their application.
My neighborhood is under served by municipal utilities (No telephone, no electricity, no water, no sewage, no cable, no pavement,) so for water most here use rainwater catchment systems using above ground cisterns or pools for storage, and various treatment methods such as UV, RO, and charcoal filtration. (Many haul drinking water from county provided spigots)
For sewage most use cesspools dug a minimum of 12 feet deep by 6 feet wide capped with concrete & steel, although those with small lots are required to use septic tank systems.
For hot water I have a solar collector thermosiphon setup augmented by a propane tankless (on demand) water heater.
For electricity I use PV panels (8 Kyocera 135 W panels) going through an Outback charge controller and a Solar brand voltage inverter, with 6 Interstate 6 volt deep cycle batteries for storage.
This is enough to run all of my light electronics, as well as a refrigerator/freezer and more.
For heavy electrical loads I have a backup gasoline generator, which I rarely use anymore.
Since my area has one of the highest electricity rates in the USA my system began paying for itself after less than three years.
My home has a lot of windows, which helps to provide airflow as well as making air conditioning unnecessary, thus I have no need for lighting during the day.
(I had some pictures on one of my phones, but am unable to locate them now...)
I've been interested in going off-grid for a while, but never could find the appropriate time (or the location, since land here is pricey as well). If you do find those pictures, I'd love to see how you've setup everything. There's a big demand these days for off-grid and sustainable living so if you happen to document your experiences, a la blog or similar, that could be invaluable for a lot of folks. Nothing really beats getting the details from someone who actually walks the walk.
How do you like living off-grid? I imagine you've had more than your fair share of hiccups on the way.
While the initial expenses related to going off-grid may be exorbitant (to some) the resulting savings more than makes up for it, and you can always incrementally add to your system as finances permit.
I have had damage due to electrical storm, but placing a TV antenna higher than the panels has worked for the past 10 years or so.
Another concern is equipment replacement, with batteries being replaced at about a five year interval, depending on usage and maintenance. Most of the newer panels are warranted for 25 to 30 years at 90% of rated output but the panels will continue to produce power for many years afterward.
You'll learn to be frugal if you begin with a small setup, as I did, but that's what we're trying to to so I've adjusted well.
My electronics are definitely better off as a result of cleaner power from my pure sine wave inverter, which produces much better electricity and no voltage sags or spikes unlike our local municipal power monopoly.
Yes, I thought the first things to go would have been excess luxury. An annual budget for maintenance, I think, actually wouldn't be too hard to setup if the rest of your expenses are proportionally lowered.
I've been told that metal roofs are a better fit with solar panels, but that's an additional cost. Hopefully that will pay off in longevity.
I hadn't thought about expanding incrementally. I can see how that will significantly make things easier as upfront costs won't be as far out. Also, efficiencies are better with newer models so you actually end up paying somewhat less per watt.
Frugality is something I've had some (involuntary) experience with in the past. ;) I don't think it'll be too hard to return to some of that. Also it's better for all of us in the end.
This headline is offensive. Nowhere in the article does he indicate that he is proud to be poor. Not that there would be anything wrong with that — quite the opposite, in fact, however, this headline reeks of elitism.
Hmm. This would also be really useful in doing underground greenhouses.
A tin sheet is cheap. You dig a hole, however long, wide, and deep. Then, you can get in the hole and plant whatever in there. Once done, you can cover it up with the sheet (or wood or whatever) and put the bottle-lights inside.
That way, you keep the pests out of your new garden.
It does not seem like that would be very practical.
Very few economically important plants will thrive in anything less than full sunlight. This makes sense because most plants become economically important because they are productive (good at turning sunlight into something we want like calories or wood).
The exceptions are plants that are grown for some valuable quality which is only needed in scarce quantities, like some spices or flowers.
Yeah, I didn't understand the hydroponics comment at the end. How does it work better to grow plants indoors than outside if you're using a limited amount of sunlight indoors? Are there other factors that make it worth it?
Down below, a deck prism illumination is astonishing. Drilling a round hole in the cabin sole is way easier, and a discarded plastic bottle is far less expensive than a vintage Criitenden & Willcox prism. Separate the bleach if you get real thirsty? Watch your head(pun?).
The main difference here is that deck prisms are flat on top, which limits the amount of light entering the prism. The water in the bottles is filled to the top, creating a dome shaped concentrator. Since water has a refractive index close to glass (~1.3 vs ~1.5) the bottom of the bottle has a similar effect to the deck prism, except with slightly more light.
Interesting invention. For me, the main thing to learn from this is how much some people depend on artificial light during daylight hours (a reminder of how important hands-on experience is when hacking things to help others).
The numbers don't make sense to me. "It depends on how strong the sun is but it's more or less 40 to 60 watts." <- I hope that's for the whole roof we see in the picture, not for a single bottle. What's the insolation of a single bottle top anyway? (Unless, of course, they're talking about your grandma's old-fashioned incandescent light bulbs.)
Well, at the surface, when the rays are hitting perpendicular to the planet, it's 1000 W/m^2 (approx).
Of course the real problem is they are measuring the light in terms of incandescent bulb power draw, rather than something useful like lumens or candela, but due to a century of ubiquitous light bulbs, we've been rating light in the wrong units.
All I can think of is that a black cap won't degrade as quickly because of ultraviolet exposure. Most plastics (long polymers) have chemical bonds that can be broken by the energy level provided by ultraviolet photons, so over time they turn from polymers into quasicrystals and lose their strength -- disintegrate. But a black plastic, by excluding the ultraviolet light, protects itself and lasts much longer.
So a bottle that's composed of a clear plastic that naturally resists ultraviolet degradation (there are several) should be capped by a more rigid plastic (to maintain its shape). So the cap needs to be black (or at least a dark color).
A reflective cap would work just as well at first, but plastics are made reflective by being painted, and the paint soon falls off, because of ... wait for it ... ultraviolet exposure.
White objects are not perfectly reflective and whiteness is not so much a function of reflecting them well, but reflecting them relatively uniformly in the visual range. Not every white object reflects UV.
Black plastic lasts longer because 1) the UV is absorbed by the pigment, not the polymer and 2) the pigment limits UV penetration to the surface.
> I thought black objects absorb all wavelengths, and white objects reflect them all away.
The point about a black piece of plastic is that the energy is absorbed at the surface -- it can't penetrate the plastic to any significant depth. That means the majority of the plastic is protected from the ultraviolet wavelengths that would destroy it.
> Real world materials are rarely ideal black bodies (or ideal reflectors).
That's true, but it's also true that all objects eventually reach thermal equilibrium with their surroundings. Were this not the case, it would violate the law of energy conservation, and that's a law that's never broken.
In that sense, most objects, solids and plasmas in particular, are reasonable black bodies once they achieve equilibrium. Some of them show spectral lines -- emission, absorption or both -- but in most cases those lines appear on top of a blackbody curve. The sun, for example -- perhaps surprisingly, it exhibits a classic blackbody spectrum appropriate to its surface temperature, with many spectral lines contributed primarily by its comparatively low-pressure atmosphere (http://commons.wikimedia.org/wiki/File:Solar_Spectrum.png).
The state of matter least like a black body is a low-pressure molecular cloud in space, which often shows only emission and absorption lines, no classic blackbody curve. The lowest pressure gases show the narrowest spectral lines, which is how we can estimate the pressure of a remote cloud of gas illuminated by distant energy sources.
Sure, but to the extent they're imperfect radiation absorbers, they're also imperfectly black. It's like how we can discuss pi and circles even though the real world has no perfect circles.
The explanation is lot simpler in practise than most comments have explained so far.
From my own experience, in lame terms, if you use non-black caps, for arguments sake let's say you use a red cap from a coca-cola bottle, that red cap will reflect some light as well as the water.
And inside the room the bottle will not "shine" as bright as it could and depending on the Sun's position the room will have red'ish rays - like a rainbow.
It automatically turns itself off at night. And then back on again in the morning; and not in with the shocking "argh! my eyes!" suddenness of an incandescent, but a gradual taper that allows your eyes to adjust slowly.
Also, you could use a cup and a rubber-band to cover it if you needed darkness mid-day.
I thought of this general idea many years ago, but then decided it might be better to cut up the bottles, flatten the plastic and sew the flat pieces together to make panels to use in roofs and windows. Never got around to actually doing anything about it though.
At some point, Heineken shipped mostly-oblong bottles to somewhere in the Dutch West Indies for use in walls. I have the impression--I read this years ago--that it was more or less a hobby of the owner. Still, it worked.
My dad built a treehouse with exactly this with liter water bottles in ~1994, he said he saw it when he was growing up with glass bottles. I hate to be a spoil sport, but this is hardly a new idea.
I've this guy on TV a long time ago. I'm certain it was at the 90's, but I don't remember the exact year.
It's not a new idea in any way, and was certainly invented more than once. Yet, it was this guy that (by luck) made the life of several people better by communicating it.
I spent a bit over a year promoting and installing these devices in rural West Africa (see http://gamlight.org). I actually wasn't aware of Mr. Moser, having taken inspiration directly from the Liter of Light project (http://literoflight.org).
In terms of light, a single bottle is insufficient, but ten are enough to light up a mud block-walled, corrugate metal-roofed schoolroom. Since there's virtually zero monitoring of kids' eye health and ability, that can mean the difference between learning to read and learning to look like you're paying attention for young students.
A few things to address:
Night: these things don't produce any light on their own (they're essentially low-cost deck prisms). A lot of people in-country at the time I helped promote these were excited at the possibility that a full moon might produce sufficient light to see, but it's just not enough. You need to supplement these things once the sun's down.
Windows: most of the buildings in rural West Africa are build of mud block, which isn't the most stable or solid of construction materials. It's cheap and readily available, but needs to be built thick and without large windows, or with significant reinforcement to any large windows, or else it crumbles. That means there's very little light coming into these rooms, even in the most sun-kissed of places. Bottle bulbs are an order of magnitude cheaper than installing iron-reinforced windows.
Transparent/translucent roofing: when this stuff is available at all, it's questionable whether it will fit the corrugate pattern of an extant roof, and the quality of the translucent roofing plastics we saw in The Gambia and Senegal was quite low; it would go milky and then opaque over just a year or two, and cost more than replacing a bottle bulb would. By contrast, you can purchase corrugated tin roofing and roofing caulk in just about any West African city, and relatively affordably at that. The bottles themselves can be found cheaply or free anywhere that tourists or aid workers spend time.
Black caps: it's not the color that matters, it's covering the original cap with something more durable. Once you've assured that there's no leaks in the bottle-corrugate metal interface, the cap is the most likely point of failure on these bulbs. The sun is STRONG in these places, which is a lot of stress on opaque plastics; once weakened, a small crack is enough to emit water vapor, and so a bottle bulb's contents would evaporate, requiring replacement.
The real tricks involved are getting a good seal between the bottle and the corrugate tin (we used roof caulking), and making the whole process relatively efficient (it can take a while to punch these out). Once you've got that down, the production and installation process can be taught to locals, who in turn can turn a profit with their labors. I worked with one carpenter for about a year before returning to the states, and he's since picked up a few contracts with the local ministry of education and a few individual customers to install bottle lighting systems.
I would be happy to go on about these things for HOURS (and have, in the past)! They're a niche solution, but they fit their niche extremely well.
The problem with the article is that they're obfuscating the fact that this does not produce light. It's basically a smarter way to poke a hole through your ceiling. It's not a device that converts energy into light.
Rather odd thing to say. How it works is explained in the second paragraph after the intro :
"So how does it work? Simple refraction of sunlight, explains Moser, as he fills an empty two-litre plastic bottle."
I agree that it does involve poking a hole through the ceiling, but the thing's simplicity belies its utility and what may seem "obvious" after the fact doesn't make it any less significant an invention.
I saw that sentence with the word "refraction" and I wasn't sure if it was the whole idea or if refraction was just one part of a clever design to enhance the effects of another artificial light source.
That's why I felt it was misleading. Looking at the article again, though, it's probably clearer than I originally thought it was.
No, people absolutely take the hot sun all the time when they have to go out, they need it because their homes are dark even in the day and there's stuff you want to do inside the house in the day, like cooking, cleaning, studying...
In poorer areas, houses are sometimes made by essentially stacking up and leaning sheets of metal against a few pieces of wood, more or less. Decent windows often aren't a very viable solution. Light bulbs would be usable, but you sometimes have to get electricity (if available at all) by literally running a wire either directly to the power line or across the road and then stringing it up to the power line yourself. So your comment misses a key point about life in these countries.
Wow, I didn’t think there’d be two comments saying this. This is about slums in Brazil and the Philippines, you should look up the conditions of the housing the people there live in.
This is pretty high on the disconnection from reality scale.
"Most homes and businesses in the slums of Dhaka have no
power and no windows, so 80-90% of them hook up to
electricity lines illegally - and fall back on candles or
kerosene lamps during regular blackouts."
