San José, Costa Rica, since 1956

University lab taps the power of the sun

It’s kind of like getting the band back together, except with engineers and solar ovens instead of musicians and guitars.

After a roughly 16-year hiatus, the Costa Rican Solar Energy Association (Acesolar) rides again, and they want nothing less than to capture the sun.

“In reality, the association never stopped doing research or promotion of solar power. In 1996, we just took a little rest,” said Shyam Nandwani, professor at the National University (UNA) and a 30-year veteran of solar energy promotion in Costa Rica.

Today, research continues at UNA in the country’s only solar-energy laboratory in Heredia, north of San José. Meanwhile, the newly reconvened Acesolar is back working on renewable-energy solutions for Costa Rica and market opportunities for investors wanting to develop a solar-energy industry in the country.

“We see ourselves being collaborators,” said Rolando Madriz, a researcher and instructor at UNA’s solar laboratory, and UNA’s representative to Acesolar.

That collaboration includes helping businesses interested in developing the solar-powered industry with academic and financial support so that investors can recognize opportunity. 

The fruits of UNA’s solar lab – solar ovens, water distillers, dehydrators and other equipment – sit under the sun in an open lot outside the university’s physics department. Madriz gives a tour of the facility to demonstrate methods for harnessing the sun’s heat and power.

There are only a few solar panels found here – none of the hundred-panel arrays sometimes found in the Southwest United States. Photovoltaic solar cells that turn the sun’s radiation into electric current aren’t produced in Costa Rica, Madriz said. The cost of the cells themselves, plus the additional cost to import them, put photovoltaic arrays outside of the average investment cost to make them viable for widespread use in Costa Rica.  

Much of the lab’s research is geared not toward to photovoltaic production of electricity, but toward thermal solar energy – harnessing the sun’s heat that enters our atmosphere and channeling it to some productive end.

“Market opportunities exist for all these thermal-solar technology applications,” Madriz said, flipping open the glass lid of a solar oven. Mirrors reflect the sun’s glare and heat inside a box where temperatures can exceed 121 degrees Celsius (250 degrees Fahrenheit). 

Solar Power 2

Solar dehydrator.

Clayton R. Norman

“Almost 2 percent of [Costa Ricans] don’t have electricity and has to supplement basic necessities with alternatives. The idea is to give them access to this technology,” he said.

In Santa Cruz, in the northwest province of Guanacaste, Acesolar and UNA’s solar lab have worked with Sol de Vida Foundation for two decades to help women build solar cookers based on a design from the lab. Madriz said the area generally relies heavily on firewood for cooking, a practice that can lead both to deforestation and air pollution.  

Sol de Vida sells solar cooking devices, including solar ovens and parabolic solar concentrators, and runs Casa del Sol – a house run entirely on solar energy. Demonstrating the use of a parabolic solar concentrator at UNA’s solar laboratory, Madriz poked the end of a wooden stick into an area where the sun’s beams are concentrated. Smoke billowed from the stick instantly.

Juan Arriaga, who works at Casa del Sol, said the cookers built by Sol de Vida reach an average temperature of 160 C (320 F), and that an average meal takes up to five hours to cook. Promoting the use of solar cooking, Arriaga said, requires a change in the way people think about food and their environment.

“The sun isn’t only some strange or unusual apparatus,” said Arriaga. “It is our principal star, our principal source of energy, our principal source of life.”

“People want everything fast,” Arriaga added. “But we say that this is part of a life-concept where life can be more tranquil. … Food is one of the principal pleasures we enjoy. … So we propose that what one invests in time is returned in tranquility, health [and] nutrients.”

Arriaga said solar cookers not only avoid the use of polluting firewood, but also can offset the cost of up to 10 cylinders of cooking propane annually for a family.

The cost of building most of the solar cookers runs between $350 and $450, but provide a limitless source of cooking heat. That is, of course, unless it rains.

Sol de Vida is planning its annual Fiesta del Sol in Santa Cruz Park in April, when the sun is perpendicular to the earth in this part of the world, and more solar radiation reaches the ground. Expect things to be cooking – slowly.

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