Using the solar racing car challenge to teach about renewable energy
“Make the fastest solar car you can!” This was the simple challenge posed to the students at Swinton School, Rotherham, on a recent renewable energy project day.
Can you remember learning about electricity using a series of line diagrams filled with obscure shapes and complex equations all bundled together to represent an electrical circuit? Or do you teach about renewable energy by showing a static picture of a solar panel attached to a house? Electricity is ‘invisible’ and can’t be seen, or (hopefully) touched, meaning it is an abstract concept and one that is difficult to make relevant to students. However, electricity and themes related to its generation are major topics within the national curriculum at secondary school. The physics syllabus requires a knowledge of fuels and energy resources, and of their costs (national curriculum for KS3 and KS4, p. 63). Electrical knowledge relating to serial and parallel circuits, potential difference, and other related themes are also required (p. 68). How can these topics be taught in a lively, engaging manner?
Sheffield Science Educator, David Garlovsky, has developed an approach to teaching these environmental themes in a fun way. He visits schools, introducing students to his self-designed solar-powered model racing cars, but instead of delivering these ready-made, they come in kit form, for students to assemble. They resemble a traditional Meccano kit, but unlike Meccano, many of the components are designed with the aim of teaching a variety of physics, maths and environmental topics.
The challenge: become a solar motor champion
Children find movement interesting. That is the problem of teaching about electricity and energy using pictures of solar panels or with analogies showing pipes in a hot water system. They are simply not interesting enough. They do not move, and students cannot see or feel what is happening. But motor racing is different, and a solar-powered racing car uses the electricity it produces to create rapid movement, as the cars are equipped with powerful solar panels which generate power even under diffuse light on cloudy days. Such cars allow teachers to tap into children’s competitive spirits, and David starts every lesson by getting students into teams, with the challenge to design the best racing car possible and to race it against the other teams.
Tinkering: integrating STEM into the lesson
STEM, the integration of science, technology, engineering and maths, in one single project, covers key parts of the national curriculum, with the design and technology syllabus requiring students to use a ‘range of materials and components’ to solve their own design problems, and ‘understand and use the properties of materials and the performance’ (p89).
The solar racer integrates many of the topics of STEM while introducing an environmental theme. Sadly, engineering can still evoke an image of a bloke with a smoke-blackened face and oil-spattered hands, working in a noisy and dirty metal workshop, surrounded by drilling tools. In this out-dated view, engineering and ecology seem incompatible, but the solar racer project shows that engineering can also be environmental. Students can see that there is an alternative to mucky non-renewable fuels: they actually see that green fuels work. The use of science process skills is a significant topic under the ‘working scientifically’ part of the national curriculum where students need to identify variables, apply mathematical concepts, and make observations and measurements (p. 59, p. 70).
A unique feature of the solar racer car is the number of features that can be manipulated to influence the functioning of the car. Wheel size, solar panel elevation, car design, wiring, can all be altered, and no two cars are ever alike. The whole process involves students thinking for themselves with teachers prompting them as much or as little as required. For example, when deciding on the type of wheel to use, prompts can be used to ask them to speculate as to the speed of the car when the wheels are large or small, and ask: how could you test them? If you changed the wheel size, what else must you do? How could you make it a fair test? And this is only one aspect open to experimentation.
Teachers’ experiences have been very positive. Terry Dawson, a maths teacher comments: “The energy of children when they pick up these kits and get started is fantastic. Initially we expect students to follow the instructions provided to them; they work in groups, and once this initial stage is over we give them additional material.” Steve Barnet, a teacher of design technology, agrees: “This is just throwing them in at the deep end really.” What really impresses the teachers is the cross-curricular nature of the kits. “We give the students the basic kits and the instructions and then leave it to them to build the prototypes”, says Terry. “We can integrate whatever we want into the lessons; maths, science, even English.” Chris Williams, a science teacher, adds: “The students don’t realise they are using engineering and maths skills, but when this is pointed out to them they realise the wide ranging implications of what they are doing.”
Even the teachers don’t know where the work will go. Steve Barnet says: “We give the students ownership, and put the onus on them to find things out. What we find is that when we ask the students to adapt the buggy, they come up with some weird and wonderful designs. They will redesign this, or readapt that. They then might think they have to reduce the weight, so they begin to take things off. Later they might think about friction and how to reduce that.”
A ray of inspiration: What angle is best?
An excellent example of how inquiry can be integrated into teaching with the solar racer is deciding on the best positioning for the angle of the solar panels. We prompt students with the question: does the height and angle at which the panels are placed influence the speed of the racer? And then ask: how could you investigate this? An understanding of how the seasons influence solar luminance is mentioned in the national curriculum (p. 67), and use of this challenge helps teach the concepts involved. Students can actively observe how different light qualities influence the functioning of the racer. For example, what happens to the car (and why) when it runs into a shadow? Students typically see that the car slows as it enters a darkened area where not enough light can be collected by the solar panels. From this initial observation, a more detailed study can be made.
When we asked: “if you raise the panels what might happen?” one student, Liam, thought the car might “collect more sun and go faster.” We then dismantled the panel and raised it so it was distinctly tilted, and Liam could see how this affected the performance of the car. Another student decided to put aluminium foil behind the racer to direct light onto the panel. Such questions can be used to initiate a series of investigations, with students having to decide how to conduct the study. They have to realise that it is not enough simply to raise and lower the panel, but all other aspects of the racer must be kept the same when the panel is placed at different heights. Students can experiment trying out different combinations, before deciding which angle of alignment is the most productive. After studying this problem, students can then relate their observations to how the strength of the sun varies at different times of the year because of the Earth’s rotation and its tilted axis.
A renewable fuel
The national curriculum requires students to learn about the production of carbon dioxide by human activity and its possible effect on the climate (p. 64). The solar racer provides a way of introducing this topic. We use it to prompt students to compare the solar car with conventional cars, asking: what are the advantages and disadvantages of each? There are now increasing numbers of electric and hybrid cars on our roads, and the solar racer allows students to investigate at first hand the advantages and disadvantages of each. The solar racer uses renewable, sustainable solar energy, and shows that this is not simply dream thinking but is a method with real potential to replace diesel or petrol driven cars in the future.
Special emphasis is put on the recycled nature of the parts used in the car. As much as possible every component of the kit is made up of pre-used material. For example, the plastic wheel arches are made up of reclaimed credit cards, and the boxes the cars are delivered in are made of recycled materials. In this way, students use material from existing products to make new things for new purposes. They mimic what happens in the actual car industry where new cars contain increasing amounts of recycled and refurbished materials. All this has the additional advantage that students learn to be creative. For example, although students are offered a number of different types of wheel, some came up with the idea of using old CDs instead. These proved beneficial because they caused no rolling resistance and were light, although they had trouble on uneven ground.
Solar Active! has been using these cars in schools around Sheffield for over 15 years. Over this time, it has modified their make-up, and developed a range of accompanying teaching materials. A basic conviction remains, however, that such hands-on, investigative activities help bring renewable energy alive in a way that formal teaching never can. It’s also the case that, over this period, concerns about our changing climate have intensified, and our need to move to renewable forms of energy because of this have become clear. This project has the potential to help students engage with both these vital ideas.
National Curriculum (England). 2014. Key stages 3 and 4 framework document. Department of Education.
Mark Walker is a research assistant at Sheffield Hallam University. David Garlovsky is managing director of the environmental charity Solar Active! – new.solar-active.com For more information, please contact firstname.lastname@example.org This article was first published in NAEE’s Summer 2016 journal, Environmental Education (Vol. 112). To read more articles like this, you can join the Association and receive three journals a year.