Thursday, May 19, 2011

Solar Panels -- A Photo Essay

The grade nine applied science students have decided that they like the class because “we never do any work”. Well! Let me tell you about what we did this week and you decide!
 Step One: Initiate and Plan      (ENGAGE)
Our school, St. Pius X High School in Ottawa, had a solar panel array installed over the summer months as part of our board’s commitment to renewable energy the solar array is used to capture the sun’s heat as a means of heating the hot water used throughout our school. Since we are currently studying the ecology unit, I told the students about this initiative and arranged an onsite field trip for them to observe this process from beginning to end. The students were encouraged to use their digital cameras, cell phones and other electronic devices to take photos of the various stages involved in the creation of our hot water.
Step Two: Perform and Record                        (EXPLORE)
On the first day of our “field trip” the head custodian took us up onto the school’s roof. This was fairly time consuming since we had to climb up a ladder and, in the interest of safety, only one person could be on the ladder at a time. Once we were all on the roof we observed the solar panels, what they looked like, which way they were oriented, the angle they were set at and the two large pipes attached to them. These two pipes were clearly labelled “glycol in” and “glycol out”. After much discussion and many photos we descended the ladder and now class was over. So no work? Any learning?

On the second and third days of our investigation to observe how our school uses the sun’s energy to generate all of our hot water, we followed the path of the glycerol pipeline from where it enters the school building to a small room tucked away at the back of our library. Here we checked the temperature gauges that showed the temperature of the glycol prior to entering the tanks. Inside the sealed tanks, we were told that the glycol pipe encircles a central core containing water and the heat is transferred from the glycol to the water. By comparing the temperature of the glycol as it left the tanks, to return to the roof, we realized that there was a temperature differential of 21 degrees C. Again we took lots of pictures before proceeding to the schools’ basement where we observed the boiler where the water that was heated by the glycerol is held until it is needed, at which point it is mixed with cold water, if necessary. These students have only been attending this school for less than three weeks so it was thrilling for them to go behind the scenes in the out-of-bounds areas of the school that are the domain of the custodians! Two more days with no work! Boo hoo! For the first time ever there was homework however! The students were told to email or forward the photos they had taken to me.
Prior to the next class I collected all the electronic photos that I could and posted them in my mailbox, which is available for the students to see on our school computers.
Step Three:  Analyze and Interpret    (EXPLAIN)
Day four we went to the computer lab. For all but two of these grade niners this was their first visit to the computer lab since entering high school. First I had to teach them how to log on to our network and then show them how to retrieve the photos from my mailbox and import them into Microsoft Photo Story.  Although none of them had used Photo Story before they actually figured it out before I had time to show them. Any technical questions they had they asked each other and I was just along for the ride. Another day with no work! Yay!
Step Four: Communicate                        (EXTEND)
Day five we continued creating our photo essays of “How Hot Water is Produced at St. Pius”. About half way through the day one of the new comers to my class asked me to review his understanding of the project with him. He explained the whole system to me starting with the glycerol circulating through the solar panels in the roof and ending with the hot water coming out of the taps. “You mean to say that all the hot water for this whole school is made just from the heat of the sun?!” he clarified. “Yes, yes it is”, I replied. “So it doesn’t cost the school anything to make all the hot water for this whole building? The cafeteria? The washrooms? Everywhere?” his eyes were widening! HIGH FIVES ALL ROUND! They got it! Sadly, another day with no work. I wonder when they will realize they are learning?

Here is a sample of one student's finished product. Send me a tweet @EurekaTeacher and let me know what mark she deserves.


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