Much ado about SALt: Myths and facts about 'salt water powered' lighting

Much has been said in the wake of the Asia Pacific Economic Conference (APEC) about Engr. Aisa Mijeno's Sustainable Alternative Light (SALt) initiative, with many a glowing praise heaped upon her "invention" of the "salt water powered lamp."

And with no less than US president Barack Obama and Alibaba founder Jack Ma—arguably two of the most powerful men in the world—joining in the accolades, you could be forgiven for thinking that SALt is a wonder short of an absolute miracle.

But the hype surrounding SALt is fraught with misunderstanding and misreporting that conflate its meager albeit substantial achievements—and, worse, could derail constructive discussion of SALt's actual merits.

Not a new invention

In the first place, contrary to most media outlets' accounts, the technology at the heart of SALt is not a new "invention".

Mijeno herself concedes this on the SALt webpage: "This lamp uses the science behind the Galvanic Cell, the basis for battery-making."

The principle of the Galvanic Cell is over two centuries old; it was discovered by the Italian scientist Luigi Galvani in the 1780's.

Not on salt and water alone

And neither does SALt run exclusively on salt water. This is just a misconception propagated by news headlines touting the device as a "salt water powered lamp".

Even the most powerful leader in the world got it wrong: "Aisa... is selling lamps that run on nothing more than saltwater," Obama said at the APEC summit.

Nothing could be further from the truth.

Essentially, the salt water only facilitates the disintegration of a piece of metal—called an "anode" electrode—that is immersed in the solution. It's the disintegration of this anode, rather than the salt water itself, that produces electricity.

So saying that SALt is powered by salt water is as absurd as saying that a car runs on air:  in an engine, air is essential to the combustion process but it's actually the fuel that does the work. In the same way, the salt water in SALt lamps is just an electrolyte and it's the electrodes that generate electricity.

Unfortunately, this explanation has been obscured in the popular press, leading to a widespread misconception that SALt lamps need nothing but a continuous supply of ordinary salt water for them to run indefinitely.

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.

Addressing concerns

But Mijeno seems focused on addressing most of these concerns.

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.

Furthermore, in a rare interview early Thursday on News To Go, Mijeno said that she is looking to have replacement electrodes available even in sari-sari stores. 

"Gumawa po kami ng design na madaling mapapalitan ang electrode para kahit sinong ordinaryong tao ay pwedeng palitan ito. (Also) Unilever is offering us help for distribution logistics, so yung mga electrode refills ay pwedeng makita kahit sa mga sari-sari stores," she told News To Go's Howie Severino.

The real miracle

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. — GMA News