As you study the heat and the sun, or alternative power sources, this is a great infographic to show. This infographic centers on solar power in the United States. It shows the cost of using solar power, and the benefit of it. According to this infographic, solar power is a great alternative to using fossil fuels.
Using this infographic, discuss with your students how the suns rays get to Earth, and the concept of light years. Also, discuss with them how various forms of alternative energy are converted into electricity. Begin with sharing how mills used water power to move gears. This would also be a great way to discuss the discovery of electricity. Try to figure out various avenues of creating sparks and what creates them.