In this video Paul Andersen describes the relationship between energy and forces. When objects are directly touching electromagnetic forces can result in forces and energy exchange. When objects are not directly touching fields;...

After pedaling for hours, Adam discovers there's a difference between the power you use and the power your body can generate. [3:41]

This short video on photovoltaics explains what happens inside solar cells and solar panels. [1:11]

This short video illustrates the alternative forms of energy used by the Center for Sustainability at Penn State University to generate electric power: solar, wind, and biodiesel. [1:58]