Grad students' light idea could help feed world's billions

Demographic experts say the Earth’s population, about 7 billion now, could reach 10 billion by 2050. And Mattos, who grew up in Brazil, may have a better idea than most what the future will look like. His hometown is Sao Paulo, the planet’s seventh largest city. Its population is about 11 million — or more like 22 million, if you count the entire urban area anchored by the city.

But Mattos, a University of Georgia engineering graduate student, hopes he can help chart a way around the problem of vanishing agricultural land and find a way to feed the world’s billions — so-called vertical farming, growing crops indoors in tall buildings using artificial light.

But so far, the energy costs are too high — 25 percent to 35 percent of the entire cost of production — to make vertical farming economically feasible, he said.

Mattos hopes to cut those costs with a lighting system that combines LEDs and a computerized feedback system, and now he has a $30,000 scholarship to Silicon Valley’s Singularity University that could help him develop the idea into a commercially viable application.

Mattos’ idea, and the research he’s already done on it, helped him win a contest to become this year’s UGA representative to the summer course at Singularity. He’ll be one of 80 bright students from around the world who will gather at Singularity for 10 weeks beginning June 16.

The university aims to find solutions for the big problems of the future — like feeding the world’s people, maintaining water quality and keeping people safe.

The students will work on projects together, and will meet with technology industry leaders and investors.

“The most important thing is the networking,” said Mattos, who has already formed a company in hopes of marketing the lighting system he’s developing.

He’s been working on his idea in a laboratory at UGA’s Bioconversion Research and Education Center on Whitehall Road, where UGA scientists have been working for years to find ways of converting plant material into energy fuels such as diesel or ethanol.

Mattos is using algae in his first experiments, but eventually his lighting system will be applied to bigger crop plants.

His idea is simple in concept, but complex in application.

He puts little vials of algae suspended in water into chambers lit by LEDs, short for light-emitting diodes.

He varies how frequently each sample receives tiny doses of light, and also the color of light — blue, green or red. As the algae in the little vials begins to grow, the plants absorb more of the red and blue light. But as the algae grows and reproduces, the vials become more opaque and the algae begins to use more green light for photosynthesis.

Mattos is trying to figure out the optimum light conditions for the growth cycle. When he does that, he will use that information to build a kind of feedback system.

Sensors constantly measure how efficiently the plants are using the light, and can switch the colors and frequency of light exposure depending on how efficiently the algae is using the light.