Date: 12/03/2016 02:17:36
From: dv
ID: 858539
Subject: SALt lamp

With some bemusement I read various articles about the SALt (Sustainable Alternative Lighting) lamp. Its development by Aisa Mijeno of the Philippines was announced last year. I’ve been reminded about this by reading an article in which Obama mentions this lamp.

Here is a typical example:
http://news.abs-cbn.com/lifestyle/gadgets-and-tech/08/02/15/pinay-scientist-creates-lamp-runs-saltwater

MANILA – “To light up the rest of the Philippines sustainably” was the vision of Filipina scientist Aisa Mijeno when she made the Sustainable Alternative Lighting (SALt) lamp.

The SALt Lamp is an environment-friendly and sustainable alternative light source that runs on saltwater, making it suitable to those who live in coastal areas.

It can also function well in remote barrios. With just two table spoons of salt and one glass of tap water, this ecologically designed lamp can run for eight hours.

According to Mijeno, the idea behind the SALt lamp is the chemical conversion of energy. It utilizes the scientific process behind the Galvanic cell, but instead of electrolytes, the SALt lamp uses saline solution, making it harmless and non-toxic.

Compared with kerosene lamp, the SALt lamp is also a lot safer, Mijeno stressed since it does not have components and compounds that may spark fire. Moreover, it does not emit toxic gases and leaves minimal carbon footprint.

For one thing, salt water IS an electrolyte so it makes little sense to say that it is being used INSTEAD of electrolytes but moreover, it was obvious that it can’t be the case that salt water is the only thing being consumed here. Salt water is very much at the bottom of the food chain in terms of enthalpy. It is pretty much only good as an electrolyte. I let it go at the time, but I’ve now looked up the explanation:

http://www.gmanetwork.com/news/story/545090/scitech/science/much-ado-about-salt-myths-and-facts-about-salt-water-powered-lighting
Much ado about SALt: Myths and facts about ‘salt water powered’ lighting


The all-important anode

The eventual disintegraton of the anode means that it has to be replaced on a regular basis, and this is the lynchpin of SALt’s potential failure or success: an entire manufacturing and supply chain needs to be developed so that replacement anodes can be cheaply acquired with minimal environmental impact.
This raises important questions about the practicality and sustainability of the entire endeavor, one of the most salient being: Why build a captive market around this non-renewable technology, when solar power and other renewable energy sources are already fully developed and well established?
And what of the waste products generated from the manufacture and consumption of these anodes? That’s to say nothing of the carbon footprint from making and delivering these to rural communities.
The anode also poses potential limits on the usability of the SALt lamp itself: its design and composition put serious limits on how bright the lamp can be and how long it can operate.

For one, she claims an anode lifespan of half a year: “Using SALt lamp 8 hours a day every day, with proper maintenance, will give you an anode lifespan of 6 months,” according to the website.

In its present form, SALt solves one problem by replacing it with another one. It addresses the need for off-grid lighting but supplants the dependence on fossil fuels with a potential dependence on processed metals.
Creating a sustainable supply chain of accessible, durable, cheap, and eco-friendly electrodes seems like a next-to-impossible fool’s errand—but Mijeno’s entrepreneural spirit seems more than up to the challenge.
Her efforts, if successful, could lead to the widespread adoption of SALt lamps among rural communities.
And that, more than any misplaced awe over a centuries-old technology, would be a real miracle worth highlighting.

I’m not dismissing this development, perhaps this is some very efficient or cheap galvanic cell. It appears as though Mijeno has been pretty upfront about the fact that the light works by depleting an anode that must be regularly replaced, but journos somehow misunderstood or glossed over this fact.

I’m still a bit surprised that science writers could just churn out the articles stating that it runs on salt water without ever thinking “What a moment, that makes no sense at all.” Anyone with a high school level of science knowledge should have twigged that something didn’t add up.

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Date: 12/03/2016 02:39:46
From: dv
ID: 858540
Subject: re: SALt lamp

I’ve found a few more specs. The brightness of this lamp is only 90 lumens.

That’s not very bright. For comparison, an old 60 W incandescent bulb gives out about 700 lumens.

90 lumens is about equivalent to a small reading lamp. Better than a kick in the bum, I suppose.

Top notch white LEDs have a luminous efficacy of 140 lumens/W, so we’re looking at about 1.5 W.

The predicted price of the electrode is $3, for 8 hours per day use for 6 months.

$3 for 1.4 kWh …

More than 2 dollars per kWh …

It is starting to sound like less than a bargain but I suppose it is still cheaper than batteries and a good option for someone who can’t be connected to mains power.

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Date: 12/03/2016 06:24:30
From: Spiny Norman
ID: 858541
Subject: re: SALt lamp

Sounds like they’re sponsored by …

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Date: 12/03/2016 07:31:53
From: Michael V
ID: 858547
Subject: re: SALt lamp

Were you able to discover the anode (and cathode) compositions?

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Date: 12/03/2016 09:03:27
From: The Rev Dodgson
ID: 858564
Subject: re: SALt lamp

dv said:


I’m not dismissing this development, perhaps this is some very efficient or cheap galvanic cell. It appears as though Mijeno has been pretty upfront about the fact that the light works by depleting an anode that must be regularly replaced, but journos somehow misunderstood or glossed over this fact.

I’m still a bit surprised that science writers could just churn out the articles stating that it runs on salt water without ever thinking “What a moment, that makes no sense at all.” Anyone with a high school level of science knowledge should have twigged that something didn’t add up.

I think you are being a bit over-charitable to science journalists there.

But yes, it would be good if at least specialist popular science journals printed a clear statement of what this light can and cannot do.

Could manufacture of these anodes be an efficient way of storing electricity?

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Date: 12/03/2016 09:05:23
From: The Rev Dodgson
ID: 858565
Subject: re: SALt lamp

dv said:


It is starting to sound like less than a bargain but I suppose it is still cheaper than batteries and a good option for someone who can’t be connected to mains power.

How about solar + rechargeable batteries?

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Date: 12/03/2016 09:28:20
From: fsm
ID: 858570
Subject: re: SALt lamp

There is a good explanation of this technology here…

Deconstructing SALt’s saltwater lamp

http://www.rappler.com/science-nature/ideas/113626-salt-lamp-how-it-works-challenges

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Date: 12/03/2016 17:13:12
From: dv
ID: 858721
Subject: re: SALt lamp

Michael V said:


Were you able to discover the anode (and cathode) compositions?

Perhaps unsurprisingly, they seem to be keeping that under wraps.

How about solar + rechargeable batteries?

Mmm, though I note the initial outlay for this kit is low.

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Date: 13/03/2016 15:32:09
From: mollwollfumble
ID: 859096
Subject: re: SALt lamp

Used to be able to buy a children’s science experiment kit where you added salt water, or lemon juice, to make it go. Same principle. May still be available.

Yes dv, total rubbish.

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Date: 15/03/2016 14:57:41
From: dv
ID: 859771
Subject: re: SALt lamp

For that matter, it is competing with cheap wind-up lamps like this.

https://www.buysend.com/au/Product/Details/148809?U=yellowstone-4-led-lantern-windup-outdoor-camping-caravan-lighting-lamp-light/&gclid=Cj0KEQjwwpm3BRDuh5awn4qJpLwBEiQAATTAQU3eL5iQ_MfhwSWJ1BsS40DQezA7×0qSuyGcAaxKALMaAtXy8P8HAQ

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