Solar-powered enthusiasm

[we arrived in Toronto yesterday PM after a long trip back and are at my brother Craig’s in Bracebridge right now.  We squished all and everything into mom’s small car. We make our way to our cottage in a moment, then back to Peterborough on Sunday.  We will be completing the blog over the next # of days.  The last # of weeks in Mpugu were such a blur that we did not have a chance to write about what was happening – and lots did!.  Cam]

Our house in Mpungu does not have hot water.  The thermostat has been broken for years, so we’d have to turn on then remember to turn off the heater before it boiled over.  Then about 6 weeks ago the element burned out so we’ve been doing bucket baths with the kettle since then (’cause it is actually cool in the mornings!).

In early June I purchased materials to build a solar oven and a solar hot water heater with my two physics classes.  I told them in class about the projects, and invited them to join with me in building.  I’d hoped that I’d have at least a half-dozen to help.  The next day (Saturday) I got the materials out at the school and some hand tools and invited the group.  Fist I had 3, then 6, then 10.  By an hour later I had about 20 of them eagerly helping!  The last time I used a hand saw to cut plywood was when I was small, with my dad.  All I had at my disposal was an old dull handsaw, and many metres of very thick plywood to cut through.  NO PROBLEM!  They jostled for position to get to use the hand-saw.  They practically lined up to take turns with the screw driver.  It then dawned on me that none of these boys (only boys at this point) had ever held a tool before!  So, imagine the excitement when I pulled out the electric drill.  And better yet, when I showed them the butane torch we would use to do the soldering.  They cut and sanded about 30 little pieces of copper pipe for the solar hot water heater, then I told them it was time to solder.  Each got to hold the torch for about 30 seconds, and each got to touch the solder to the pipe and watch it melt.  I stood back for a moment and almost cried, watching their enthusiasm and sadly what it represented – a lack of access to real hands-on projects.  By the end, though, I think their favourite tool was the angle grinder – mostly because it made lots of noise and produced even more sparks.

One afternoon while we worked I pulled out the boom box so we’d have some music.  This was a big hit, to say the least – our workforce went from about 15 to about 30 in a matter of minutes.  I have a very vivid memory of them dancing to Bob Marley – as they painted and sawed!

The projects slowly came together over the next 6 weeks.  Sometimes I would be too busy to work on weekends.  Sometimes I would be short a small part or tool – and the nearest store 2 hours away, so would have to wait for another teacher to pick up for me.

Perhaps the greatest satisfaction came one day about 3 weeks into the projects.  I was working at the house on both projects with 6 or 8 boys, when one of my female students showed up.  No girls had helped yet, despite my continuous invitations.  I actually thought she had come to ask me about something else … then realized she wanted to help!  Then another came.  And another.  And soon I had all 8 girls from my grade 11 class there.  They dove in with the hand tools.  When I invited them to use the power tools they were reticent, and the boys suggested it wouldn’t be a good idea. But I shoved the tools into their hands, and the smiles lit up and away they went.  I treasure the photos below of them with the soldering torch and the power grinder.  They were quite proud I think, and really took an interest in the projects from that point forth.

We finished the solar oven about 3 weeks ago but only 5 minutes before the final wire connector was put in place something came loose and a wing on the oven fell onto the glass plate and cracked it!  You can imagine some of my choice words. I did not want to leave the school with a cracked solar oven so bought a new piece in town last week and it is now complete.  We cooked solar bread and solar peanut butter cookies to celebrate, and have since generated quite a bit of interest from passers by, because the oven is actually quite large and shiny (see below).  This was actually one of my goals – to get people looking at and talking about low-tech solar projects.  This particular oven would be perfect for a village to share.  The oven works beautifully, though does not reach the same temp as conventional ovens, so takes twice as long at least to cook.  But we would put our dinner in at 11:00 AM and forget about it, then pull it out at 5:00 and it would be ready to eat.

The final delay came from a lack of welding-ability.  The one guy who welds in town was never around.  A Mpungu Primary teacher — Mr Haindongo (who I’d worked closely with on the fence project) had just bought an arc-welding machine, but we couldn’t get it to work.  So I ended up begging a welder who lived 55km away in Nkurenkuru to come and help us out.  He arrived only on the Monday before we left so it was down to the wire.  We mounted the collector about 1.5m up, behind our house, facing NORTH into the sun.   I unpackaged the 4ftx4ft piece of glass and was pleased to find it had survived the 180km trip (much on bumpy gravel) 6 weeks earlier.   I connected the black plastic pipe so it would feed the hot water tank (which would now act only as a hot water storage tank).  I told the learners to come by in the morning to see it come to life with the water coming on (there is almost never water in the afternoons).  Unfortunately I was up till 4:00 AM that night working on the computer lab, so I was not thrilled that about 12 of them took my offer seriously and were knocking on our door at 6:45 AM!  I struggled out of bed, opened the tap and  …. found a myriad of leaks in the black pastic connections. DRAT!  These should be the easiest connections.  I told them I’d figure out something, which ended up being to use silicone in the seals.  Next morning (now 2 days before departure) I again turned on the water and … found 4 leaks in our copper joins and leaks still in the black plastic joins.  I had WAY too much to do in my final 2 days to solve these leaks, and was immensely frustrated and disappointed.  Those of you who know me understand that I am a stubborn problem solver and I’d never had to face defeat like this before.  I was especially disappointed for the learners who had poured their hearts into these projects and were so anticipating the results.  I did fill up the system though and let it work for the day.  By days’ end … the storage tank was full of warm/hot water, so at least we know that the design of the collector worked.  The learners were actually very good about accepting the status of our heater.  And I have some small hope that the guy who helped me weld will come back to help fix the leaks. We got to be friends over the day and I’ve spoken to him several times since.  My co-physics teacher will contact him.

This project was further evidence that these learners CRAVE hands-on learning.  And learning it was, because they were perfect examples of heat transfer – solar radiation, conduction of the metal plate into the copper pipes, and convection (the hot water rises out of the collector into the tank, while cold water in the tank falls into the collector – a beautiful loop with no “pump”).  The solar oven was  a good demonstration of the greenhouse effect.  All of these topics we covered in depth in class as part of our syllabus.

I would publicly like to thank the students and staff at Peterborough Collegiate (my school) for raising $500Cdn to purchase the supplies for the oven and collector.  And also my friend Sean Flanagan, for providing the design for the hot water heater and helping me adapt the design to my Mpungu setting.  Sean is in the renewable energy business in the Peterborough area ( and can be contacted if you are interested in building your own collector.

It is going to be hard to get excited about solar energy upon return to Canada – Namibia is a solar geek’s dream.  But I know Canadian students are as keen as Namibians to get involved in this sort of thing, so I have something to come back to!


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