ACTIVITY. What use is Solar Power? What use is Solar Power? Learning objectives. Resources (per group of 4 children) Introduction

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1 ACTIVITY Learning objectives To: describe how we can use the Sun to generate electricity give examples of where solar power is used design and build a solar powered vehicle explore how gears can convert and transfer energy 2 hours Resources (per group of 4 children) Activity Sheets 1-4 Construction materials for the car: Photographs of solar powered devices such LEGO Technic or other studded as satellites, Mars Rover, solar roof panels building bricks or materials Solar powered devices such as a torch, garden 1 electric motor plus connections light or calculator (to be attached to the solar panel) 12 small (3v) solar panels with wiring Drive axles to turn the wheels 1 light bulb (1.5v) Cogs to turn the axle Sunlight or an electric light Introduction Show the children the range of solar powered objects, photographs of solar powered devices including the photograph of a solar powered car (Activity Sheet 1). What do they all have in common? In pairs, the children discuss, draw or write their ideas before sharing them with the class. Explain that solar panels collect clean, renewable energy in the form of sunlight and convert that light into electricity which can then be used to provide power for electrical devices. Show the children a solar panel and explain that it is made up from several solar cells. Connect the solar panel to the light bulb. Ask what they think will happen if the solar panel is covered? Demonstrate that a solar panel without light does not produce power. The children investigate connecting the solar panels to the lamps and covering the panels with their hands. Explain that solar panels are also often used in satellites and space vehicles so they can generate their own power. Show the children a photo of ESA s Rosetta spacecraft s large solar panels (Activity Sheet 2). 52 Solar Orbiter exploring the Sun s realm ESA/AOES 53

2 Activity Explain to the children that they are going to make their own solar powered rover. First, they must draw what their rover will look like. They must take into account the conditions the vehicle needs to meet. These are described on Activity Sheet 3. It is not compulsory, but it is helpful if the children take the following points into account when designing their rover: the rover needs wheels to be able to move the electrical wires need to be connected to the solar panel the electrical wires need to be connected to the motor the motor needs to drive the cogs the cogs need to turn the drive axle that turns the wheels Once their designs are approved, each group collects a solar panel, motor, connections and other construction materials they need for their design and constructs a prototype. To test their rover, the children place their solar panel in direct sunlight or under an electric light. Does the vehicle move? Discuss why some move and some do not. Encourage the children to make adjustments until they are successful. Plenary Discuss what is required for a vehicle to run on solar power. Ask the following questions: What difficulties did they encounter? What changes did they make to their designs? How successful were the final vehicles? Can they think of any disadvantages of solar power? Encourage the children to share what they learned when making their own solar powered rovers. Establish that the solar panel converts light energy into electrical energy that drives the car. In conclusion, using the internet, the children could research images or videos of landers and rovers from current space missions such as NASA s Curiosity Rover or the European Space Agency s Rosetta mission. Extension Read the from the Space Agency (Activity Sheet 4), explaining that the children are going to be space engineers for the future, designing a novel solar powered product. Talk to the children about the importance of renewable energy for the future. Think about the everyday objects that we use and think about how they could design something that would be practical and save energy. Share an idea such as a hat that has a solar panel on the top which will power a fan to keep cool in hot conditions. When the groups have completed their designs, they will be asked to present their ideas to the class. They must remember to explain how and where the solar panel will be connected. Each group could be awarded marks for creativity and practicality and the winning team a certificate. Information for teachers Construction materials Small solar panels and motor kits may be purchased from educational suppliers such as TTS or Rapidonline. A single sealed solar cell measuring 6cm by 9cm can produce approximately 100mA in direct sunlight and can successfully be powered by a bright light source. Space landers Early space landers and rovers relied on solar energy captured by solar panels to produce electrical power but more recent developments employ nuclear energy that can be used day and night; this energy is supplied by the decay of radioisotopes that provide heat which is converted to electrical energy for keeping the craft s instruments from freezing and for moving across the planet surface. ESA s Rosetta Mission The European Space Agency s Rosetta spacecraft is a large aluminium box with dimensions 2.8 x 2.1 x 2.0m. The scientific instruments are mounted on the top of the box (Payload Support Module) while the subsystems are on the base (Bus Support Module). On one side of the orbiter is a 2.2m diameter communications dish the steerable high-gain antenna. The lander is attached to the opposite face. Two enormous solar panel wings extend from the other sides. These wings, each 32m 2 in area, have a total span of about 32m tip to tip. Each of them comprises five panels, and both may be rotated through +/-180 degrees to catch the maximum amount of sunlight. 54 What Use is Solar Power? 55

3 Activity Sheet 1 Activity Sheet 2 ESERO Netherlands ESA s Rosetta Spacecraft and Comet 67P European Space Agency 56 What Use is Solar Power? 57

4 Draw the design for your rover here: Activity Sheet 3 When building your rover, you will need: A solar panel Sunlight or other light source Construction materials When designing your rover, think about these things: 1. The rover needs to be sturdy (so it won t blow over if it is windy) 2. The rover needs to be able to move forwards 3. The rover needs to be powered by a solar panel and light Your rover might look like this: 58 What Use is Solar Power? 59

5 Activity Sheet 4 Appendix: The story of the Rosetta Mission Rosetta is the first space mission to journey beyond the main asteroid belt and rely solely on solar cells for power generation, rather than the traditional radio-isotope thermal generators. The new solar-cell technology used on the orbiter s two giant solar panels allows it to operate over 800 million kilometres from the Sun, where sunlight levels are only 4% of those on Earth. Rosetta gets its name from the famous Rosetta Stone that led to the deciphering of Egyptian hieroglyphics almost 200 years ago. Scientists hope that Rosetta will unlock the mysteries of how the Solar System evolved. Rosetta has made a rendezvous with Comet 67P/Churyumov-Gerasimenko, where it will make the most detailed study of a comet ever attempted. It will follow the comet on its journey through the inner Solar System, measuring the increase in activity as the icy surface is warmed up by the Sun along its elliptical orbit. It will also land a probe called Philae onto the comet s surface. The mission is due to end on 31 December From: UK Space Agency Dear Pupil Space Engineers As you know, renewable energy is very important for our future because fossil fuels such as oil and gas are being used up. Solar power is a clean and free source of energy. We are challenging you to be space engineers and to design a new kind of solar powered product for use by the crew in the International Space Station or by our astronauts here on Earth when they are training for future space missions. Think about the everyday objects you use and think about how you could design something for them that would be practical and save energy. We look forward to hearing about your ideas and receiving your designs. Chief Engineer UK Space Agency Comets are believed to be the primitive building blocks of the Solar System, and probably helped to seed the Earth with water, and maybe even life. By studying the nature of the comet s dust and gas, Rosetta will help scientists learn more about the role of comets in the evolution of the Solar System. The lander will focus on the composition and structure of the comet nucleus material. It will also drill more than 20cm into the subsurface to collect samples for inspection by the lander s onboard laboratory. Rosetta was launched in March 2004 by an Ariane-5 G+ rocket from Europe s spaceport in Kourou, French Guiana. To place it on the required orbit to rendezvous with Comet 67P/Churyumov-Gerasimenko it received four gravity assist manoeuvres: three from Earth (4 March 2005, 13 November 2007 and 13 November 2009) and one from Mars (25 February 2007). Rosetta also passed by and imaged two asteroids: 2867 Steins on 5 September 2008 and 21 Lutetia on 10 July The spacecraft entered deep space hibernation in June 2011 and was woken up in January 2014, before rendezvousing with Comet 67P/Churyumov-Gerasimenko in May It will follow the comet around the Sun and as it moves back out towards the orbit of Jupiter. The lander, Philae, was delivered to the comet s surface in November The spacecraft consists of two main elements: the Rosetta space probe orbiter, which features 11 instruments during the operational phase of the mission, and the Philae robotic lander, with an additional nine instruments, including a drill to sample subsurface material. The main spacecraft has two 14 metre long solar panels. It carries instruments for remote sensing and radio science, and instruments to study the composition of the comet s nucleus, as well as the comet plasma environment and its interaction with the solar wind. The orbiter has 11 scientific instruments. Rosetta is one of the most challenging missions ever many of the complex navigation and landing manoeuvres need to take place automatically with absolutely no room for error. The issues and complications of sending a small spacecraft halfway across the solar system and soft-land on a small comet are immense. A large number of complex scientific instruments have been accommodated on one side of the spacecraft, which must permanently face the comet during the operational phase of the mission. The spacecraft needs to endure both extremes of temperature, from that of deep space to very close to the active comet. Complex spacecraft navigation needs to take place at low altitude orbits around the dust and gas jets of the comet which also has a weak but asymmetrical, rotating gravity field. 60 What Use is Solar Power? 61