Do-it-yourself solar panels become classroom project


Jul 25 - McClatchy-Tribune Regional News - Pam Sohn Chattanooga Times Free Press, Tenn.



If an East Ridge High School class can build a reasonably priced solar panel in the classroom, why shouldn't anyone?

They should, says East Ridge High School environmental science, biology and French teacher Davis Mounger.

With some reading and talking to shop colleagues, he said he made a project plan.

 "There's not a whole lot of variation (in how solar panels are made). It's a frame. It's cells. Wire in, wire out," he said. "We just had to sit down and figure out what's the best design we could come up with, with the tools that we have. We don't have mass production tools. And the main thing was getting each panel sealed up to be watertight, and getting out maximum wattage."

The first panel, though cumbersome to make over about 16 hours by a small class in the spring, exceeded the teacher's expectation.

The second, built last week as a senior project by Iraqi student Bashar Al Gorges, is an improved design and went much faster.

"I already knew how to solder," Mr. Gorges said. "I learned how to use the (other) tools."

Each panel the class has made will, with sunlight, produce about 70 watts of power, Mr. Mounger said.

That doesn't seem like much -- one incandescent light bulb. But Mr. Mounger said a smarter use would be a bank of LED lights. A 3-watt LED is equivalent in output to a 45-watt incandescent light.

"One thing I'm trying to teach these kids is that nothing is free. If you want to be more efficient in your production of power and consumption of power, you have to think things through. You have to understand where your power is coming from and how you're going to use it," he said.

Tami Freedman, a member of the Cherokee Sierra executive committee, said Mr. Mounger's project with East Ridge students should show the public that solar energy is not just for the rich. On Monday, the Sierra Club is hosting a meeting for Mr. Mounger to tell the public how it can be done and what lessons he has learned with the two projects.

"Now anyone -- yes, anyone -- can make a small solar panel to power their homes with solar energy and save money on electrical bills," she said in a promotion for the talk.

Most commercial solar panels cost about $400. The panels built by East Ridge students and Mr. Mounger cost under $150.

The solar cells -- photodiodes --are the expensive part, and the school was able to purchase them wholesale, the teacher said. Photodiodes are semiconducters capable of converting light into either current or voltage.

The school's first panel will power some of the outdoor monitoring for Mr. Monger's science projects at the school, he said. The second likely will power some LED lights in the electrical 1 classroom.

Does he a foresee a time when a class or classes of students could fill a school rooftop with panels?

"It would be nice," Mr. Monger said. "It's certainly doable; we just have to get that grant (for materials)."

 

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