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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