Can Saltwater Light Homes?



salt3Salt plus water equals light? An innovation by brother-sister team, Aisa and Raphael Mijeno, is set to provide a safe, cost-effective light source to rural communities in the Philippines.

Across the Philippines’ over 7000 islands, many rural communities are not connected to the electrical grid. Kerosene lamps are the chosen alternative; however, this fuel is highly flammable and acute and chronic exposure can cause skin irritation and damage to the central nervous system.[1]

Kerosene is also difficult to obtain for those without access to transportation. “What the people do is, they walk for 12 hours just to buy a bottle of kerosene,” says Raphael. “And that’s good for two days.”[2]

Aisa began considering ideas for a sustainable light source while working for Greenpeace Philippines, immersed with an indigenous tribe in the north. Water and salt are two basic items found in every household, and she was looking for a way to combine these ingredients as vital components in the light.

Working as a part-time engineering instructor at De La Salle University in Lipa, she began developing a prototype in the university lab. A local incubator, Ideaspace, prompted the next step: establishing the startup Sustainable Alternative Lighting, or SALt.[3]


Eight Hours on a Glass of Water


salt2The handheld lamp is powered for eight hours by a glass of water and two tablespoons of salt, or ocean water for those in coastal communities.[4] It is modeled after a Galvanic cell battery, but with the electrolyte as a non-toxic, saline solution – saltwater – unlike most other designs.

When two different types of metal are submerged in the water, each reacts and gives up excess electrons to the seawater. The electrons travel to the opposite metal via a wire, creating an electrical current to power the LEDs. On the user end, one simply needs to pour water into the base of the light and flip the switch. It even has a USB port for charging small electronics like a smartphone.[5]

Prices are currently unavailable, but SALt ensures the retail cost will be at an affordable level (though current estimates range from 20-30 USD, a high amount for low income families). Beyond initial costs, the metal anode will require replacing every six months if the lamp is used eight hours a day, or every year if used as an alternative light source. SALt states that the lamp and its components will be more cost-effective than kerosene or battery-powered lamps, as the fuel is free.[6] At this point, SALt has released limited hard data on the light output, manufacturing targets, cost or charging specifics.


Scaling to Meet Demand


salt1However, with several awards to their credit, the project is well on their way, especially considering their product has not yet been put into mass production. “We’re looking to get the final prototype out before the year ends,” says Raphael. [7] Production is in the early stages, and the launch will be confined to the Philippines as they test and improve the beta version.

As they scale their business to meet demand, their business aim is to produce for partner organizations – non-profits, foundations and local governments who will purchase and distribute the lamps – and hand-picked communities, with lamps provided by retail sales, premised on TOMS’ One for One model.[8] Three communities, with 770 families, have already been chosen: the Hanunuo Mangyan Tribe, the Barangay Gabi families and the Buscalan Tribe.

The potential for the SALt lamps extends far beyond the Philippines. According to the International Energy Agency (IAE), 1.3 billion people live without electricity. Not included in this statistic are all those who face regular blackouts, or the natural and man-made disasters that necessitate emergency lighting.[9] The SALt lamp has the potential to be life-changing for rural communities, allowing productivity to increase into the evening and proving a safer alternative to light their homes. To learn more, visit their website, Twitter or Facebook.


SALt Demo from Aisa Mijeno on Vimeo.













Rachel Pott

Rachel Pott

Rachel Pott is a writer, teacher and human rights advocate from Peterborough, Canada.

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