We're supposed to have sun for the rest of the week, but it's never good to take chances with the weather. So, when the sun came out today, we hit the ground running with three solar thermal projects at once.
This time, instead of working with complicated, photovoltaic, solar panels, we experimented with harnessing the heat of the sun to expand air, purify water, and turn a pinwheel. Each project was simple to put together, and provided easily observable results, but with lots of little details that could be tweaked, adjusted, or expanded.
Really I had a hard time deciding which one to write about first, finally settling on the simple solar chimney, or updraft tower we found archived on the National Research Counsel Canada website.
The chimney is made by taping together three, large, empty, clean tin cans, with the tops and bottoms removed.
A wire arch (made from an unbent paper clip) is taped across the opening of the top can...
...with a thumbtack, or straight pin, taped to the center of the arch, pointing up.
The chimney is placed on top of a couple of books, to allow air to flow in from underneath.
Finally a pinwheel - made by cutting diagonally in from the corners of a 6 inch square sheet of paper, to within a quarter inch of the center, bending the every other point from the corners to the center, and taping them in place...
...is balanced on top of the thumbtack, taped side down.
Questions for thought:
Would a paper tower work in place of cans?
Would pinwheels made of different materials, or in different sizes spin faster?
What if the tower was painted black?
Could enough power be generated by the spinning pinwheel to turn a generator?
13 comments:
Brilliant! My son would love to do this so I will be sharing with him. Although I'm not certain the UK ever has enough sun to do any of these projects!
Man, this series is AWESOME! You've inspired me again to get going on some solar ideas I had been toying with previously.
But even if I had never thought of doing solar experiments, I would want to try the solar updraft. That is so COOL!
Thank you for sharing. I always tell people that if they are looking for hands on science projects, they can't do better than your site. :)
Christy - Thanks!
Claire - We just watched Paddington Bear, and learned the English have 107 different ways to say, "it's raining". But then, I seem to remember Douglas Adams having it at 231 in one of his books.
Wow! This is fantastic!!
LOVE it! Now can I successfully make it? That is the question.
We have an excess of sun, so I really need to give this a try! Very cool experiment.
Did this for a school science fair
How does the pin wheel balance? Its just slipping straight off?
How long did it take for the fan to spin?
This is cool! Might do this for my son's science project. How long did it take for the pinwheel to spin? Was that morning or afternoon sun?
It was afternoon, and if I remember correctly, it took 15 to 20 minutes (but it was a while ago, so I'm not positive about the time).
Hi, this experiment is so cool. I have also seen your science project on the solar chimney and I am so much interested to try it on a bigger perspective. I am trying to build/create a solar heat conductor to be used for my corn dryer. I wonder if you can help me out with a more effective but inexpensive project to try.
Thanks! Your project sounds interesting - a little out of my range though.
Post a Comment