SolAsin

What it does

SolAsin is an accessible, sustainable salt farming tool for coastal communities. Using greenhousing and solar absorbers, it creates high-value flaky salt in a compact, controlled setup that is easy to set up along the coastlines.

Your inspiration

Coastal poverty is a pressing issue in the Philippines, driven by overfishing and limited livelihood options. Meanwhile, the country revives its salt industry, and I saw an opportunity to introduce salt farming as an alternative livelihood. While solar salt farming is eco-friendly, current systems need large spaces, making them costly and inaccessible to low-income families. This leaves ownership out of reach and forces many to seek work inland. Developing compact, sustainable solutions can bridge this gap, reduce overfishing, improve coastal livelihoods, and drive innovation in salt production.

How it works

SolAsin is a tray-like unit inspired by greenhouse design, made with two main food-grade materials: a clear PETG cover and a black HDPE solar absorber — both durable and safe for salt production. Its slanted clear cover protects the process while allowing sunlight to enter, creating a controlled environment with passive ventilation that shields the salt from pollutants. Flaky salt forms naturally within this protected space. For ease of use and efficiency, the black HDPE absorber is divided into two parts: a ridged, angled top and a flat, deep bottom. The ridged section evaporates faster, producing salt that is remixed into the bottom seawater to raise salinity. This repeats until the ridged section turns white, signaling high salinity. The deeper bottom then allows for slow evaporation, forming high-quality flaky salt. All processes happen within a single, low-cost unit that can be expanded to meet desired income levels.

Design process

I approached the problem by first understanding the community’s existing livelihood assets — allowing the product to adapt to the community, not the other way around. I found that while they had access to seawater and sunlight, limited coastal space and low income required a compact, low-cost solution. I started by identifying suitable salt for coastal production - I found flaky salt, a premium type that can be sold even in low quantities. I tried evaporating seawater in small dark trays covered with clear plastic. This produced a small amount of flaky salt, but with seawater at only 3% salinity, the process was slow. I then tested a tent-style version with clear covers and larger water volume. It yielded more flaky salt but was hard to set up, expensive and inconsistent — higher areas formed grainy salt, lower ones formed flakes. It also took too long due to the large volume that needed to be evaporated. These challenges led to a new design: dividing the absorber into two parts — one ridged and angled to speed up evaporation and raise salinity, and one flat and deep to allow slow evaporation for flake formation. I replaced the tent with a compact tray-style design made using thermoforming. It made it easy to set up and is low-cost.

How it is different

SolAsin is the only readily available flaky salt farming tool on the market which uses solar evaporation. It requires no landscaping, is easy to set up and remove, and is safe for the coastal environment. More than just a salt production unit, it is an accessible and sustainable livelihood tool designed to empower coastal communities. Built around their existing livelihood assets, it offers a practical source of income that is easy to operate, uses readily available resources, remains low-cost, and is non-damaging to the coastal environment.

Future plans

Although HDPE plastic has been used as liners in salt farming, I aim to develop a non-plastic material that is both durable and effective as a solar absorber — an area I was not able to fully focus on during my undergraduate years due to time and financial constraints. My goal is to produce enough units to support local communities, in partnership with local government units and environmental management bureaus, to ensure legal and sustainable implementation.

Awards

The project was selected as one of the 10 recipients of the James Dyson Foundation Prototyping Grant at the University of the Philippines Diliman.