Thursday, 16 October 2014


So I was just at Hobsonville Point Secondary School for a teacher applicant tour/meet and greet. Damn is that place invigorating. After Maurie and Claire talked to us I just had this urge to blog -mostly because they made me think of the changes I had helped make in the GBHS Science Department, and last time I wrote a post - way back in August - I promised I'd write a summary and reflection on the Year 9 Energy unit I did this year.

The big ideas for this unit are:

  • There are different forms of energy that can be changed from one form to another;
  • Energy is conserved;
  • Heat is transferred by conduction, convection and radiation.

We started off with a circle to co-construct the big question for the unit. Remember the big question frames the learning for the unit and is the topic of a project/thesis students work on throughout the unit. We discussed the word energy and where we've come across it, and aside from energy drinks and being energetic, things like the energy crisis, energy efficiency and renewable energy were brought up. A word that stood out was 'green'. Green homes, green buildings, green power, this led to the big question:

What would the ultimate green community look like?

Awesome question! We were going to design the ultimate 'green' community. We then unpacked this question and came up with five guiding questions:

  • What is meant by a 'green' community?
  • Why is it important that communities become more 'green'?
  • How should electricity be generated?
  • How can we reduce the amount of energy we use?
  • What is the best way to heat or cool a home?

Let's start learning!

The early part of the unit covering the first of the big ideas went well. We explored what makes things happen to find out what energy is and about  the different types of energy, we explored the energy transformations happening in toys and had fun designing Rube Goldberg machines. We found that electrical energy is super useful because it can be easily changed into most other forms of energy - why most of the energy we use is electrical.

How should electricity be generated?
I found a great activity looking at the energy transformations in generating electricity from fossil fuels and the environmental consequences of using fossil fuels (here - pages 12-24). I thought it was awesome how you filled in flowcharts with information from an article, then used the flowcharts to help write explanations of what causes global warming etc. This led nicely into groups researching renewable energy sources to find the best solution for our 'green' community. We had an informal debate between the groups to reach a consensus on how to power the community. 

How can we reduce the amount of energy we use?
Conservation of energy was next, we used a PhET simulation to explore the concept and then elaborated by investigating energy efficient light bulbs, and energy star ratings on appliances.

What is the best way to heat or cool a home?
Heat transfer was covered by exploring and then discussing a range of experiments. We used predict-explain-observe-explain while looking at some of the infrared videos here. Time was then given for students to research energy efficient heating and cooling solutions and to begin to design the home they would contribute to the community.

We spent some time in the computer lab using Energy3D to model our homes. This application simulates passive solar heating and heat loss through windows etc. giving you an estimate of annual heating and cooling costs.

The plan was to then print and build the model homes, however this did not end up happening. This was because many didn't end up finishing their models and we could not get into the computer lab again, printing out the models proved problematic and time had run out. This was a huge disappointment as we were not going to get to build our community. Students still submitted reports on the big question however.

Student Reflection
Several students said that the electricity generation debate and the Rube Goldberg machine designs were the highlights of the unit. Many found the Energy3D application limited and frustrating to use. Many students found the types of heat transfer the most difficult big idea. 

My Reflection
I thought the big question was fantastic! It pulled together all of the big ideas and applied them to a topical issue. The electricity generation flowchart activity resulted in some magnificent pieces of writing. The renewable energy debate went extremely well and I was impressed by how the students managed themselves and argued in a very positive and respectful manner. It was also great how they came to a consensus on using a combination of solar and hydroelectric power. We all found the house design process difficult. Next time I would provide a planning framework and  more time to spend on design. I would not use Energy3D, it was more trouble than it was worth and limited student house designs because it doesn't support curved walls and balconies among other things. I would pursue the physical models again but this time get them to build from scratch instead of trying to use Energy3D. I would love to see an entire little cardboard community with each student having built a house!

As always, questions are welcome either on here or Twitter.


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  2. Hi Aaron:

    Could you provide more info about why your students feel Energy3D is limited and frustrating to use? It would help us improve. The curved wall isn't an issue as it can be approximated by a polygon.

    Charles Xie

  3. Hi Charles, thanks for the comment.

    It was limiting in the way we were using it - in that students were designing their houses on paper before using Energy3D and then getting frustrated because they couldn't recreate their design. So instead of testing our designs in Energy3D we ended up having to redesign houses so that they could be built in the software.

    Scale was another challenge. I think it would be great if there was a human figure like SketchUp has to help visualise the scale of the house.