Energy investors looking for opportunity beyond oil and gas would do well tracking the initiatives of giant companies like Google (GOOGL 0.49%) and Wal-Mart (WMT -0.27%). The sheer size of these behemoths can make a big difference in the types and quantities of energy and energy-related products and services we consume. In this video, Fool.com contributor Aimee Duffy looks at recent moves by these two behemoths, illustrating why investors should be paying attention.