Teaching sequence

Work through this resource material in the following sequence:

15 minutes

Tune In: Energise your curiosity

20 minutes

Find Out: Analysing renewable systems

25 minutes

Take Action: Renewable energy – people and power

5 minutes

Reflection

Learning intentions and success criteria

Students will:

understand and apply the law of conservation of energy to analyse the efficiency of energy systems, including the roles of scientists and engineers in making renewable energy infrastructure more efficient.

Students can:

describe how energy inputs, outputs, transfers, and transformations occur within an energy system
analyse the efficiency of renewable energy systems by applying the law of conservation of energy
explain the development of an example of renewable energy infrastructure using a case study and a career example.

Curriculum Connections

In the previous science lesson in this unit, Exploring Energy Efficiency and Careers, students compared the efficiency of electricity generation from renewable and non-renewable sources. This lesson builds on and expands upon this knowledge by getting students to analyse the system efficiency of specific renewable projects in Queensland, exploring how engineers enhance the efficiency of these projects. Cool.org recommends teaching these lessons as part of a package.

Tune In: Energise your curiosity

Step 1

Explain to students that they will explore wind farms, wind turbines, and their energy input and output.

Explain that both the height and shape of the wind turbine blades are designed to maximise the amount of wind each turbine harnesses. Each modern turbine converts around 50% of the wind’s kinetic energy into electricity. (Source: Queensland Government Department of Energy and Climate)

Given this, prompt students with the following question:

‘If around 50% of the wind energy each turbine harnesses is turned into electricity, where does the rest go?’

Using the Student Worksheet, invite students to annotate the image of wind turbines with:

what energy the turbine harnesses
what type of energy it produces
what energy they think might be lost.

This image can also be found in the attached Visual Explainer.

Step 2

If students are struggling to think about where that 50% of energy has gone, read to them the following statement from the Queensland Government Department of Energy and Climate to prompt their thinking:

‘Wind turbines are designed to be as quiet as possible, with the average noise level of a wind turbine being 40–50 decibels at around 500m. That’s quieter than a lawnmower and even a dishwasher!’

You might also like to get students to rub their hands together quickly. What type of energy is produced when objects slide over each other?

Explain that our desired useful energy output is electrical energy. Still, in wind turbines, there are also unwanted energy outputs in the form of sound and heat (generated through the friction of the turbines and gears moving over each other).

Step 3

Show students the following image of a blank Sankey diagram using the attached Visual Explainer. If students are familiar with Sankey diagrams, task them with creating a Sankey diagram for the wind turbine example they just explored.

If students are unfamiliar with Sankey diagrams, explain that this type of image is used to represent energy efficiency. Task them with observing the diagram and thinking about what each part might represent. Prompt them by stating that the arrow starts full and then branches into 3 separate arrows. Some arrows are bigger than others and point in different directions.

Task them with using the energy inputs and outputs they annotated on their wind turbines to label the Sankey diagram with what they think is correct based on the information they have.

Step 4

Use the next slide on the attached Visual Explainer to show how a Sankey diagram is created, highlighting energy input, unwanted energy output and desired energy output. In this case, the energy input is wind energy (100%). The useful energy output is electrical energy (50%), and the wasted energy output is sound and heat energy (combined 50%).

Extension opportunity: pose the question to students: ‘If the system was made more efficient, what might the Sankey diagram look like? What does this mean?’ Invite students to draw an alternative Sankey diagram and explain what this increased efficiency means for the energy created.

Find Out: Analysing renewable systems

Preparation

Explain to students that they are learning about energy efficiency, how it is analysed and improved in renewable energy systems, and the roles of scientists and engineers in these processes. Students will be using real-world examples of different types of renewable energy.