Use dodgeball to demonstrate how we use energy
Play a game of Dodgeball with a bit of a theme. Before the game, explain to the Pack that they are energy and the Leaders are consuming the energy by hitting them below the waists with sponge footballs. Play a game with three sponge balls, throwing them around the playing area, aiming for the legs of the Cub Scouts. When they are hit they must sit at the side. See how long it takes to get everyone out and use all of the energy.
Next, play again, but this time allow the Cub Scouts to hop on one leg after they have been hit once, only having to sit down after they are hit again. Explain afterwards that this simulates technology improving our need for energy. For example, improved insulation in homes and the use of more energy efficient appliances and light bulbs.
Finally, play again, but this time use only one sponge football. It is likely that it will take much longer to get everyone out. This shows the effect of reducing energy use.