MANILA - Residents of a remote island at the center of the Laguna de Bay are turning to the lake's waters to help them power streetlights amid long periods of power interruptions in their town.

A device called iLawà is making this possible by tapping into ions in the lake's polluted waters through a submerged battery system made of aluminum cutouts from soda cans, activated carbon from water filters restrained in net, and copper wires.

"In order to produce chemical reaction, the polluted water has to be exposed to a metal," explained Professor Drandreb Earl Juanico of the Technological Institute of the Philippines' (TIP) research office.

The chemical reaction triggers the light.

Aluminum cutouts in the battery system expire after 2 weeks due to exposure to ions, said Juanico. The by-product of this process may reduce chemicals that trigger algal blooms - pollutants that usually lead to massive fish kills, he added.

Metals, ions and toxic pollutants are still present in a large portion of the Laguna de Bay as its waters have been classified as "Class C," or suitable only for fisheries and recreation.

Blackouts in Talim Island in Rizal usually last an average of 2 weeks, as torrential rains and strong winds frequently hit the town. The location also makes it hard for city-based linemen to fix the damage.

iLawà, a combination of "ilaw" (light) and "lawa" (lake), is a project of TIP students and earlier received an award from a non-government organization advocating sustainable energy. TIP students Neil Jon Carl Aguel, Ana Luz Callao, Paul Vincent Nonat, Eduardo Narciso Jr. and Erica Lois Ann Vinculado were behind the invention.

The students are currently teaching Talim residents to take advantage of the device, as the submerged battery system can also be useful to fishermen.