UP student innovates award-winning device that may revive PH salt-farming industry

While the Philippine archipelago was once a seabed of livelihood for countless coastal families, the dramatic decline of the salt-farming industry in the country is one that has been marred by urbanization, climate change, and substantial policy gaps.

According to the Department of Agriculture (DA), despite the country’s 36,000 kilometers of shoreline viable for salt production, 93 percent of its salt supply is imported—a problem a Filipino student seeks to address through design engineering. 

SolAsin, a solar-powered salt-farming unit developed by John Carlo Luna Reyes from University of the Philippines Diliman (UPD), offers an accessible method of producing high-value salt among coastal residents using only seawater and sunlight, without the need to build vast salt farms. 

Bagging the prestigious 2025 James Dyson Award, a global competition for young design engineers in developing tangible technologies to solve real-world problems, Reyes sees the innovation as a breakthrough in sustainable salt production, addressing both economic challenges and environmental concerns in a single compact device.

The salt ‘behind’ the seawater 

“SolAsin was developed to produce flaky salt, a high-quality salt that is usually imported from abroad and is in high demand in the country. Farmers can sell it at a competitive price point without competing with local table salt and artisan salts,” he said.

The device is a tray-like unit with a greenhouse-inspired design primarily made of durable black High-Density Polyethylene (HDPE) solar absorber and a clear Polyethylene Terephthalate Glycol (PETG) cover—two main food-grade materials that are chemically resistant and recyclable. 

This greenhouse concept with passive ventilation then creates a controlled environment that shields the salt from pollutants, allowing slow evaporation to take place and form high-quality salt.

“Set up the device under direct sunlight and fill with filtered seawater. Let it evaporate halfway along its ridged and angled part to produce grainy salt through fast evaporation. Remixing it with the remaining seawater at the bottom will enhance salinity and its slow crystallization at the flat bottom will produce flaky salt,” Reyes instructed in his video explainer.