Salt – Sustainable Alternative Lighting | Hacker News Reader

Salt – Sustainable Alternative Lighting

salt.ph

118 pointslisper73 comments

From the description this sounds like they are using a form of what is commonly called a lemon or potato battery (http://en.wikipedia.org/wiki/Lemon_battery). The salt water is the the electrolyte in the battery cell and the actual energy comes from a chemical reaction between the zinc and copper electrodes.

In this blog post (https://saltph.wordpress.com/2014/05/14/know-more-about-salt...) they mention that part of their revenue model is "Electrode rod refill", and in their main page (http://www.salt.ph/), under "Our Product" / "Just add water and salt!" they mention replacing the anode every 6 months. The anode they are referring to would be the zinc electrode. This is usually a galvanized nail in those popular lemon / potato battery science experiments.

Absent cost and energy storage / delivery data, this is 1) noninformative and 2) bordering on gullibility marketing.

Yes, galvanic cells work. No, they're not magic. No, the salt water doesn't "power" the solution (it enables electron flow between cathode and anode).

It's also not a rechargeable process, though it's possible to recycle the cathode/anode, generally.

Solar power or other storage cell technology would be of similar use.

I think that by using the "powered by water and salt" phrase they are trying to present the product in layman's terms. For most of the people it's sufficent description to understand the product and using the "galvanic" term wouldn't help to understand it better.

However it would be nice if they had a "how does it work?" subpage with scientific explanation - for the credibility.

They are not presenting the product in layperson's terms. They are misrepresenting it as badly as saying, "A car that runs on rubber! Just add tires!" and then making money by selling buyers gasoline.

Wonderful analogy! I liked it, anyway.

With the term "powered by water and salt", it makes it seem like the battery can be "recharged" by replacing the salt. This is not the case, when the battery loses power, the battery is "recharged" by replacing the copper and zinc electrodes (or whatever metals they are using).

So a less scammy description would be to say that is is powered by copper and zinc. This is more correct both technically and to a layman.

I disagree, it causes laymen to completely misunderstand the product. The product is not "energy from water and salt". The product is a fixed quantity of chemical energy sold in the form of the metal anodes/cathodes. This is no different than selling non-rechargeable batteries.

1. Do you think the people who will be using this are actually going to read this marketing copy? (hint: it's not in their language, assuming they are literate)

2. Their current systems involve constantly buying and rationing kerosene, candles, and batteries. Do you think 'rechargeability' is their primary concern?

Then ask yourself:

1. Who is this copy aimed at? More likely investors than customers.

2. If you're going to lie and misrepresent the story to your investors, how much respect do you suspect the company will show its actual customers?

3. English is in fact one of the two official languages of the Philippines (http://www.filipinolanguages.com/html/languages.html)

There's a bit of classic advice which says "don't do business with (or work for) assholes".

These guys are assholes.

Assholes, huh? That's funny. Because it almost seems like you've never worked with an NGO to try to convince local villages and governments to adopt a new product that upends their cultural norms with new technology. Because someone who might talk about the problems with attracting funding to the projects, without knowing anything about them, might be seen as an asshole.

1. The copy is primarily a marketing tool; it is not sales copy. For investors they may work with NGOs, local outreach organizations, file for grants, and make requests of a few private companies that work in the region. The website is just boilerplate, and any intelligent person who's attracted by the idea and works in this field is not going to assume someone is a scammer because their copy does not include technical jargon or scientific wordage.

2. They are not lying. You are arguing semantics. The product works as advertised; I challenge you to quote the 'misleading' sections verbatim so we can have a word-off. And seeing how the company is made up of filipinos and working directly with local tribes to bring them the product, I trust them a lot more than a bunch of bay area hipsters with scientifically-accurate marketing copy.

I suggest buying a good mirror.

While I would not have used the harsh words, grandparent is right in most respects.

    I challenge you to quote the 'misleading' sections verbatim

Voila:

    Sustainable and cost effective ecologically designed
    lamp powered by "tap water" and "table salt!"

The lamp is not powered by tap water or table salt. It is powered by a non-rechargeable battery. This is misleading, putting it charitably. To anyone who knows anything about energy, this is not just "semantics" it is an false claim about the fundamental nature of the product.

Perhaps they meant to put "powered" in scare quotes, not "tap water" and "table salt" but they didn't.

Edit: more examples

    You can also use the ocean-water to power up your lamp!

    Use the ocean-water to power up your lamp and it will 
    give you 8 hours of running-time.

    Store ocean-water in bottles and use them to power up
    you lamp anytime, anywhere.

To a naive reader these statements imply that the energy comes from the ocean water. It does not, therefore the statements are misleading.

There are no false claims in this web site. The entire product is explained - just not in one sentence. They explain that salt + water added to the lamp will create power, which it will, because that's the only thing the machine lacks in order to produce power. They also explain that an anode has to be replaced every six months. According to the theory of similar devices, this is all that is involved with the creation of the power, thus, this is the entire design and function of the product.

---

If you have a car, and I said "this car is powered by gasoline", would this be a misleading, false claim about the product? Would I be a liar?

According to you and the parent commenter, Yes, because the car requires a battery and spark plugs to ignite the gasoline along with oxygen.

Technically speaking, gasoline, oxygen, vacuum, a battery, spark plugs, a fuel pump, fuel injectors, an ECU, sensors, pistons, valves, and a whole lot more shit are needed to "power" the car. Without all those things there is no "power" created. What generates the power directly is spark igniting a precise mixture of gas and oxygen, which then applies force to mechanical parts. But a lot more things are involved in making that happen, and maintenance is required on most of it. All of which the average car user has no effing clue about.

You do not need to know any of that in order to 'power' a car. And I am not a liar for telling you a car is 'powered' by gasoline. I simply didn't explain the design of the internal combustion engine to you.

The car comes with a battery, spark plugs and oxygen, just like this lamp comes with an anode, and it needs regular maintenance, just like the various parts of a car. Just like gasoline for a car, water and salt are the fuel for this lamp. The fuel is the only part you need to understand to use it.

They explain several times that the anode has to be replaced every six months [based on average use]. They have omitted nothing. There is no deception. Just simple language explaining only what you need to know to use it.

> To anyone who knows anything about energy, this is not just "semantics" it is an false claim about the fundamental nature of the product

The product's users are not chemists or engineers. They're tribal villagers in the Philippines, for christ's sake. Anyone who speaks english and is intelligent enough to pay for the project will read the whole thing, just like all of us did, and realize how it works, just like all of us did, and be satisfied.

I wrote a bunch of crap below, but the point is this: do you think an average non scientific reader would come to the conclusion that the device extracts energy from salt water? If the answer is yes, then the site is misleading, because it does not. The rest is just quibbling over the definition of the word "power". Most people on this thread seem to disagree with you on that, and unfortunately words mean what the majority thinks they mean. (I'm not being sarcastic when I say 'unfortunately', it's annoying when words become corrupted through misuse, although I don't think that that's not what is happening here.)

-----

    There are no false claims in this web site.

You asked for misleading, which is what I provided.

    They explain that salt + water added to the lamp will 
    create power, which it will, because that's the only 
    thing the machine lacks in order to produce power.

By that analogy, a properly fueled car is "powered by" its ignition key, since that is the only thing the machine lacks in order to produce power. I disagree.

    If you have a car, and I said "this car is powered by 
    gasoline", would this be a misleading, false claim 
    about the product? Would I be a liar?

    According to you and the parent commenter, Yes, because 
    the car requires a battery and spark plugs to ignite 
    the gasoline along with oxygen.

You have a point about the oxygen, but not about the other components. The car is powered by the gasoline and the oxygen, since those two chemicals react to release energy. It is not powered by the spark plugs, etc. They are necessary for the car to work, but they are not a source of energy, so they do not power the car.

You could arguably say "the car is powered by its engine" with a slightly different meaning of the word power. To use that sense of the word power with respect to the lamp, I would say "the lamp is powered by its battery" - there isn't really a term that separates the source of energy in the battery from the device that converts it to the form we want.

    Technically speaking, gasoline, oxygen, vacuum, a 
    battery, spark plugs, a fuel pump, fuel injectors, an 
    ECU, sensors, pistons, valves, and a whole lot more 
    shit are needed to "power" the car. Without all those 
    things there is no "power" created. What generates the 
    power directly is spark igniting a precise mixture of 
    gas and oxygen, which then applies force to mechanical 
    parts. But a lot more things are involved in making 
    that happen, and maintenance is required on most of it. 
    All of which the average car user has no effing clue 
    about.

If we're talking to average users, I would say the two correct statements are "the car is powered by gasoline (and oxygen)" or "the car is powered by the engine".

    You do not need to know any of that in order to 'power' 
    a car. And I am not a liar for telling you a car is 
    'powered' by gasoline. I simply didn't explain the 
    design of the internal combustion engine to you.

No, but saying the salt water powers the lamp is more like saying the car is powered by the motor oil, or the spark plugs, or the carburetor. The salt water is neither a source of energy (gasoline), nor a (complete) mechanism that turns one form of energy into another (an engine).

    The car comes with a battery, spark plugs and oxygen, 
    just like this lamp comes with an anode, and it needs 
    regular maintenance, just like the various parts of a 
    car. Just like gasoline for a car, water and salt are 
    the fuel for this lamp. The fuel is the only part you 
    need to understand to use it.

No. Fuel is a store of energy. Salt water is not a store of energy (unless you're extracting the deuterium from it and putting it in a hydrogen bomb). Gasoline is a fuel. Motor oil and spark plugs are not. Similarly, a metal anode is a fuel. Salt water is not, nor copper wires (when used for conducting electricity), nor the liquid container it all goes in.

    They explain several times that the anode has to be 
    replaced every six months [based on average use]. They 
    have omitted nothing. There is no deception. Just 
    simple language explaining only what you need to know 
    to use it.

They make the anode sound like just a random thing you happen to have to replace for maintenance (like spark plugs) while the salt water provides the energy. This is exactly the opposite of what happens. The anode is where the energy comes from. The salt water is the incidental maintenance. This is what people are complaining about.

    The product's users are not chemists or engineers. 
    They're tribal villagers in the Philippines, for 
    christ's sake. Anyone who speaks english and is 
    intelligent enough to pay for the project will read the 
    whole thing, just like all of us did, and realize how 
    it works, just like all of us did, and be satisfied.

The target audience of this website are journalists and investors, not tribal villagers. Journalists and investors don't just need to know how to use the product. They need to know what is novel about it or what value it provides over other existing solutions. The website makes it sound like the novelty is extracting energy from salt water. This claim is preposterous, which is why all the commenters are complaining.

> The website makes it sound like the novelty is extracting energy from salt water.

This is your interpretation. There exists no statement which says that this is a novel product. In fact, there is a direct quote where it says this is based on a well known scientific principle, and that this is basically a battery.

> This claim is preposterous, which is why all the commenters are complaining.

You have just taken a "this sounds like" and turned it into "a claim"; you have just invented through assumptions and insinuations a problem which does not exist. The idea that these people are being deceptive is in your head.

You based all this perceived deceit on the technical definition of the word 'power', or the phrase 'to power', and their lack of a complete, one-sentence description of the operation of the chemical reaction which creates energy in the device. In the end, they do get across fully the idea of how the device works and the implications thereof. But you ignore that so you can continue to paint them as bad guys.

This is a textbook example of Fear, Uncertainty and Doubt (FUD). And it's an incredibly long troll. I'm signing off.

    This is your interpretation.

Mine, and pretty much everyone else's on the thread. If everyone interprets what you say a particular way, maybe that's what it appears to mean? And if that's not what you meant, maybe you said it wrong?

    There exists no statement which says that this is a novel 
    product. In fact, there is a direct quote where it says 
    this is based on a well known scientific principle, and 
    that this is basically a battery.

This is Michael Moore logic. This is the idea that if you say something which is technically correct, but is obviously misinterpreted by many readers to mean something else, you didn't lie, because there is an alternative technical interpretation which is correct. I don't live by Michael Moore logic.

    You have just taken a "this sounds like" and turned it 
    into "a claim"; you have just invented through 
    assumptions and insinuations a problem which does not 
    exist. The idea that these people are being deceptive 
    is in your head.

Oh, come on. I was using the word claim to refer to the concept I had just described in a previous sentence. Sadly I don't know a word that means, "the idea either intentionally or naively, but either way incorrectly, implied by someone".

    You based all this perceived deceit on the technical 
    definition of the word 'power', or the phrase 'to 
    power',

No, I based it on the colloquial definition, of "to give energy to", or to "make go". Motor oil and spark plugs don't power a car, in colloquial language. Similarly, salt water does not power this lamp.

    and their lack of a complete, one-sentence description 
    of the operation of the chemical reaction which creates 
    energy in the device.

When you're selling a battery, and you refuse to call what you're selling a battery, it makes the reader rightfully suspicious. And the (paraphrased) sentence "based on the science of batteries" implies it is different than a battery, because to a casual reader, the only reason to say "based on the science of X" is that it is not the same thing as X, otherwise you would just say, "this is an X".

    In the end, they do get across fully the idea of how 
    the device works and the implications thereof.

No, they really really don't. They just don't. I repeat: how many non-scientific readers do you think would conclude, "wow, this thing creates energy from salt water?". I would say most. An that statement is false.

    This is a textbook example of Fear, Uncertainty and Doubt (FUD).

No, the website is a textbook example of misdirection. Similar examples: http://www.dhmo.org/facts.html or if you prefer XKCD: http://xkcd.com/1481/

    And it's an incredibly long troll.

And you, sir, are a nincompoop.

I resent the creators of this product for misrepresenting how it works. Are they marketing to the gullible?

No, the water and salt do not power it - if that were the case you could revive the lamp's battery by pouring in fresh salty water. Instead, the power comes from the galvanic potential of a chunk of metal vs. (I'm guessing) a carbon electrode. When the metal electrode wears out, that's what you need to replace.

I think the product may not be without merit (edit: entirely), even though the marketing reminds me of free-energy pseudoscience. Within a region with many islands, where technology is expensive because it has to be transported by sea (with weight and space limitations increasing the cost), it may be much more cost effective if you have batteries without needing to ship an electrolyte. You can just cram more replacement anodes in a cargo hold than fully-fledged throw-away batteries.

On the other hand - solar panels might be a better investment.

I agree, and I think the focus here on the battery is misplaced. What is enabling this to work is the availability of low cost LEDs, which require very little current to operate. These open the door of all kinds of lighting with low power sources, like galvanic batteries, or as you suggest solar panels (though I am guessing the cost for solar is higher). Whether this is the optimal power source is TBD, but the core idea that lighting can be brought to developing countries at very low cost by looking at non-traditional power sources is an important one.

Based on the video posted below by coob ( https://www.youtube.com/watch?v=5vOuj_feM2s) it looks like it utilizes a well known re-active element ( Zinc-Oxide) to generate electricity.

http://sci-toys.com/scitoys/scitoys/echem/batteries/batterie...

So the real question is, how long does it take for the Zinc Oxide to be depleted, how much does it cost to replace, and how hard is it to replace?

From the landing page: "Using SALt lamp 8 hours a day every day will give you an anode lifespan of 6 months."

Okay, with a pair of big electrode plates, retail cost will be, what, $200?

You can get a 12" square sheet of zinc for under US$10 and make a couple dozen anodes from it.

Copper cathodes will be a bit more expensive, but the total electrode cost should still be only a few dollars for several months worth of light.

The electrodes are going to have to be pretty thick, chunky grids to last six months, not thin sheets, and retail price is typically a 100% markup over BOM cost.

Or the cathode is carbon. Then (IIRC) it wouldn't wear out or need replacing.

http://en.wikipedia.org/wiki/Galvanic_cell

The has energy come from somewhere. In an electrochemical battery, it comes from chemical reactions with the electrodes, which consume the electrode material.

Its basically one of these:

http://en.wikipedia.org/wiki/Zinc%E2%80%93carbon_battery

The carbon rod never corrodes. If you want to be picky its more of a zinc-manganese battery with a carbon rod as a non-corrosive wire but whatever.

As VLM explains a bit better, I was talking about only one of the two electrodes. The other one, the anode, would of course be made from zinc (or some other metal) and end up breaking down to provide that energy. I was just explaining why the battery might not need two electrodes breaking down.

>So the real question is, how long does it take for the Zinc Oxide to be depleted, how much does it cost to replace, and how hard is it to replace?

…and don't forget "how poisonous is the stuff you're dumping out?" (straight into the environment, your water/food source)

So this is a battery-powered lamp, where the saltwater is merely the electrical conduit and the battery consists of the cathode and anode, perhaps carbon and zinc. We already make batteries of this type, without the gimmickry:

http://en.wikipedia.org/wiki/Zinc%E2%80%93carbon_battery

This same lamp could simply have a wire between the carbon and zinc, with an on-off switch - no need for saltwater except to fool people into thinking the salt is providing the energy.

It's very hard - impossible - to imagine how this device is superior in performance or cost-effectiveness over any sort of commercial light with a battery. An LED or three connected to a lantern battery, auto battery or other "large" battery will last forever, with self-discharge being the biggest problem.

LEDs with solar cells are nearly free, and last forever. Here's one for $1.98 retail, Canadian:

http://www.lowes.ca/solar-landscape-lights/paradise-stainles...

In the not-distant past, many people were concerned about electric lighting in the developing world. Cheap solar cells and cheap LEDs have solved that problem, permanently. In the near future, I'd expect to see the average third-world village a million miles from nowhere be lit up like New York City after dark.

> This same lamp could simply have a wire between the carbon and zinc, with an on-off switch

Seems unlikely that there's no trade off to this, can anyone confirm? Also, it has an on-off switch.

Superior performance, No, it probably performs worse. But cost-effectiveness?

Salt water is free.

Why is everyone missing the point here? This is not for a geek in San Francisco, this is for someone in a remote village on an island in the Philippines that doesn't have a damn corner store to go pick up batteries at, but does have plenty of salt and water. The materials will simply survive better in this environment than traditional batteries, and need to be replenished less.

Why is this so hard to grok?

    Salt water is free.

Salt water is not the point. The anodes and cathodes and the LED lamp are the point.

    corner store to go pick up batteries at

The electrodes need to be replaced regularly. Where will the replacement parts come from? That problem is equivalent to having to "pick up batteries".

    The materials will simply survive better in this 
    environment than traditional batteries, and need to be 
    replenished less.

How do you know this? It doesn't say so on the website that I can see. Are you an expert on batteries (not sarcastic)? I'm not but I'm guessing a lot of engineering has gone into existing battery technology, including batteries for rugged environments and/or long term usage.

Wow, you missed the point hard. I guess I just assumed that people knew about galvanic cells... Okay, I'm sorry, let me backtrack.

The salt water has absolutely nothing at all to do with the operation of the lamp and it is not providing the electricity to operate the lamp. Salt and water are not used up or expended in the operation of the lamp. It's like the "lava" in a lava lamp. The lava isn't providing the power. It's decorative.

What is providing the power are two materials of different electronegativities, which we call a cathode and an anode. They are expended in the operation of the lamp. They are not free, are not available on remote islands, and are to be purchased - like any other batteries - from the supplier of the lamp.

Your response is exactly what the makers of this lamp are hoping for - people who don't know the science ending up believing that salt water powers this lamp, somehow. You have been deceived by their marketing.

EDIT: I responded to your one comment above without reading the rest of your comments in this thread. Had I done so, I would have been much less nice, as it is clear you are highly, highly ignorant and highly resistant to numerous people's attempts to educate you.

I would be a lot happier with this if they had some actual numbers. As in, how much light does the lamp produce and how much does it cost to replace the electrodes after the 6 months?

Or even just a price listed. I'd consider buying one for my home to fulfill my once-in-awhile prepper thoughts.

Heh, I think everyone with a good imagination has at least lazily considered being a prepper...

It looks (if they are using the same technique as the youtube video linked in this thread) that once it has expired you either need to change the lamp or potentially replace the salt water with an aqueous solution of (very strong) reducing agent. Or you could be even use saltier water in the lamp to make it last (slightly) longer once it has expired.

As others have pointed out, this is a battery-powered lamp which needs salt water as its electrolyte, but gets its power from a separate consumable. There's nothing wrong with that per se, but the way they work so hard to distract attention away from the battery is pretty scummy. Flagged, and I encourage others to do the same.

They state in the first paragraph of explanatory text, "Replace consumable every 6 months!" No, they don't emphasize this, but they don't hide it either. I think flagging this is a bit harsh.

I'm going with flagging it, because the salt water is an irrelevant, uninteresting side show. Compared to the cost of the anode and cathode material in the first place, the salt water is free, so the question is "why are they even making you put it in?" to which I can only answer "deception". No, seriously, I took a moment to try to come up with an explanation that didn't involve that, but given the physics here I can't. Pitching this as either "sustainable" or "cheap for the developing world" is a lie, or some sort of collective ignorance (where no one person involved quite understands what is going on) that amounts to much the same thing.

wikipedia is a little wishy washy about "may leak". Much more realistic to write "will leak".

http://en.wikipedia.org/wiki/Zinc%E2%80%93carbon_battery#Lea...

Kept dry, it should store infinitely?

The greenwashing and poverty-washing or whatever is pretty awful. But an eternally storable battery is kinda interesting.

This is extremely dumb. We already have units powered by a Zinc-Oxide reactions in a conductive medium. They're called "bad batteries". They got replaced by things called "better batteries". Any distribution challenge of shipping new anodes every 6 months is going to be equal or greater than the challenge of shipping a 24pk of new batteries.

It's neither sustainable nor cost effective.

You use ocean water to create electricity, and you only have to pick up a new anode once every 6 months. How is this not sustainable or cost effective?!

You have to pick up a new anode every 6 months only if you're powering a tiny, incredibly energy efficient LED. You could power the same LED for 6 months using 6 Li-Ion D Cells.

Um. What exactly is your percentage in defending these guys?

I'm sorry, but as cool as this sounds, I closed the tab as soon as I read the words "it's a SOCIAL MOVEMENT".

Why does everything have to be a goddamn social movement nowadays? It's a lamp powered by salt and water (and - presumably, if I'm understanding this from years of playing with lemon and/or potato batteries - some cathode and anode, since salt water by itself isn't what's creating the electrical charge). That's already awesome enough. Did you really need to muddy that up with all this "sustainable" "eco-friendly" bullshit?

So, the anode is effectively the battery. It lasts for some time, then you have to get a new one. So the question is in the price and availability of the anodes.

Can I pee in it? (Serious)

yes. charge lifetime depends on the salinity of the urine

Uh. Why do you want to pee in a salt water powered lamp?

Because every human being is a walking, convenient source of an electrolytic solution. This is something you can do if you're too, too lazy to mix and pour water and salt.

The downside is that you'll probably end up with a smelly lamp, and some of the other crud in your urine may muck up your electrodes.

I wouldn't recommend trying it, but the question, asked in the hypothetical, was valid and justified.

Curiosity, and the fact that you could possibly be stranded in the wilderness without salt and use your body as a refinery.

They said ocean water is 35g salt per 1000g of solution. http://www.salt.ph/

Urine is 40 mEq/L which is approximately 2.3g per 1000g of solution. http://www.healthline.com/health/sodium-urine#NormalResults5 http://www.elephantcare.org/millequi.htm http://www.sengpielaudio.com/calculator-milligram.htm

This puts you at 6.6% capacity or 31.5min of light.

Output time won't scale with salinity that way. Conductivity will vary more-or-less linearly with salinity, and output power will vary more-or-less linearly with conductivity, so with lower salinity you'll get less light (lots less light) but the battery will last for a concomitantly longer time.

Batteries run on the anode/cathode pair--not the electrolyte, as this page dishonestly suggests--and as such the total energy available will be determined by those, not the electrolyte.

If you wanted to use urine in this device you'd be best to concentrate it by evaporation to get a reasonable output brightness.

Wow, this definitely seems to play into the hands of the gullible. Given two pieces of information (salt water + replacable anodes) we can deduce they are building zinc-air batteries. The same kind of battery is described on the Sci-toys[1] site.

Basically this is a great way to sell Zinc. Not exactly "renewable" since it takes more energy to turn zinc-oxide back into zinc than it produces when zinc reacts with air.

On the plus side, carrying round zinc and copper (for the cathodes) without the electrolyte is easier than full up batteries. And you may be able to get water and salt on site. As a bonus you should get ZnO precipitating out of the solution as the anode corrodes.

[1] http://sci-toys.com/scitoys/scitoys/echem/batteries/batterie...

Here's a bunch of smart, socially conscious people in the Philippines trying to create a cheap, mass-market, sustainable product for the many inhabitants of remote villages that have no reliable source of light or electricity, and all the commenters of HN can say is "they didn't explain properly how the power is generated! scammers!!!"

Talking about not seeing the forest for the trees.

The complaint isn't that they "didn't explain properly". The complaint is that they sensationalized an inaccurate explanation, without addressing the fundamental technological question: is this better than existing battery technology and if so how? Does it last longer than current batteries? Didn't say. Is it cheaper? Didn't say. Is it less toxic? OK, they said that it is non-toxic, I still don't know if it's less toxic than existing alternatives. If you want to convince people that you have a superior technology, well then you have to actually explain your technology, not just say OMG Electricity from Salt Water!

This would be a great idea for emergencies where one loses power for an extended time. I researched emergency equipment and ended up buying several hand crank flashlights.

Solar lamps tend to be too bulky and cumbersome. This would be a good application for a whole room solution. I think there is a bigger market for these than they think.

Search for [solar reading light] on Amazon; I see lots of inexpensive, not-bulky-or-cumbersome products for sale.

OK... so how does this work? Fuel cell?

https://www.youtube.com/watch?v=5vOuj_feM2s

Thank you for posting this. I was wondering how it worked also.

Title wouldn't hurt for your bare-naked URL: "How to make a Salt Water Battery Lamp."

(I was expecting a spoof meme along the lines of "Magic" and very nearly downvoted your comment simply based on that expectation.)

http://en.wikipedia.org/wiki/Galvanic_cell

For the record, one of the mods changed the headline from what I originally submitted. My original headline was "Water + salt = 8 hours of light". The actual title of the page is "SALt - It's a Social Movement."

Electricity from water and salt? Why don't they just use cold fusion?

Great.. Just watched this youtube video Energy from Salt water

https://www.youtube.com/watch?v=VMdS65_E_X4

Nice site, very cool product. Small tip — the quotation marks are unnecessary (and kind of amusing) in the following line:

> powered by "tap water" and "table salt!"

This is true. It should say:

"Powered by" salt water and table salt

Before I read the page to find that this is an actual project from the Phillipines, I thought the ".ph" was just a clever domain hack.

show me the schematics

How is this possible?

It's not. It's a scam; the battery is the metal.

Reply on news.ycombinator.com