Solar power comes from the energy of our Sun, a yellow dwarf star located 93 million miles from the Earth. It is a middle-aged, mid-size star compared to the billions of other stars in the universe. The interior of the Sun is a region very high in temperature and filled with dense gases. The Sun's core is estimated to be approximately 27 million degrees Fahrenheit. Heat and light from the Sun are produced through a process called nuclear fusion
. Sunlight is an excellent energy source and the future of using solar power is very exciting. The Sun's energy can be used to heat and cool buildings, generate electricity, operate communication and navigation systems and even power solar cars, like the ones in the General Motors Solar Car Sunrayce featured in the Newton's Apple segment! Solar-powered cars all get their fuel from the same place - the Sun. The cars use hundreds of photovoltaic cells to convert sunlight into electricity. Each cell produces about one-half volt of electricity. When the Sunrayce teams design their electrical systems they have to allow for variations in sunlight. The Sun's energy powers the car's motor and charges a battery for use when the Sun is hidden by a cloud. If a car is designed to put all of its energy toward driving and keeps nothing in reserve, it will stop completely in cloudy weather. If too much energy is diverted to the battery, the engine runs too slowly to keep up in the race. Engineers and scientists still have many questions and problems to tackle before solar power becomes an efficient and economical way to fuel vehicles. But as the demand on fossil fuel
resources increases, research will continue to search for alternative energy sources, including harnessing the Sun's energy to drive a vehicle. The most exciting part of using solar power as an energy source is that it is pollution free and inexhaustible. If research continues, one day solar energy may replace today's combustion engine cars!
Build a custom-designed vehicle propelled by photovoltaic cells.
- 4 small solar cells
- Small 1 1/2 volt motor propeller
1. Place the solar cells side by side. 2. Connect them in a series by twisting the negative and the positive wire of one cell to the next cell. 3. Attach the motor to the remaining positive and negative wires. 4. Attach the propeller to the motor. Observe how fast it turns. 5. Design a custom body for the car. Compare your's with your classmates'. 6. Try a few time trials to see who’s car is fastest. How can you modify your car to make it go faster?