Earth & Space Science
Solar energy use is explained and one application is demonstrated as students build and race solar cars.
After completing this tutorial, you will be able to complete the following:
Because our modern culture centers around energy usage, it is important to differentiate between various types of fuel. It is especially important to understand the difference between fossil fuels and alternative energy.
Fossil fuels are fuel sources that come from the decay of organic material buried underground for millions of years. Examples of fossil fuels are coal, petroleum, and natural gas. These types of fuels are easy to use and have been used for centuries. However, they are a finite resource, and scientists discovered that they have a negative and potentially lasting effect on the Earth's atmosphere
To reduce the use of fossil fuels (called nonrenewable because the supply of these fuels is limited), scientists have developed ways to use renewable resources, which are energy sources that are easily replenished. Examples of renewable energy are wind, solar, and geothermal.
Most solar cells, or arrays, are comprised of linked photovoltaic cells, which are sheets of glass coated in metal compounds that react to sunlight. The sunlight causes electrons in the coating to ionize, generating direct current (DC) electricity. This can be used to power devices that are not hooked up to a traditional electric grid. For many home and business applications, however, the DC current must then be converted into alternating current (AC) electricity. As solar energy is not efficient all the time (i.e. at night or on cloudy days), excess energy generated by the solar cells is often stored in batteries.
In a solar car, a solar panel captures sunlight, converting it into electrical energy. The excess energy is stored in batteries mounted on the car. To use the electrical energy generated by the solar panels, a motor converts the electrical energy into mechanical energy, which is used to power the vehicle.
|Approximate Time||30 Minutes|
|Pre-requisite Concepts||Students should understand the meanings of battery and motor, and the concepts of distance, speed, and energy.|
|Course||Earth & Space Science|
|Type of Tutorial||Concept Development|
|Key Vocabulary||battery, electrical energy, energy|