The idea of energy is a tool to think with–suitable for some tasks but not for others.
You could knock a nail in with an adjustable spanner, or maybe even tighten a screw. But for some tasks, the spanner is particularly well-suited – by design. The idea of energy has evolved in precisely this way–whereas it is possible to try and describe every process with energy, it is not fruitful to do so.
Teach energy by choosing examples which illuminate by developing plausible, intelligible and fruitful insightful descriptions. Then children can learn to reason with the idea of energy in ways that do not distort its usage in the scientific community, by engaging with meaningful and purposeful descriptions.