A common approach when teaching about energy in circuits in secondary schools is to treat flowing electrons as carriers of energy from a source to a sink. The paper argues that although this may seem to be a useful model for teaching, it is unscientific and may ultimately be confusing to students who continue to adopt it at key stage 4 and above. A "system view" is suggested as an alternative, in which some parts of the system play the role of connectors, not carriers. Parallels are drawn with mechanical systems. A teaching approach that uses a system view of circuits is recommended because it is both scientifically sound and pedagogically powerful. (Contains 3 figures.)