I suppose having non-technical terms makes sense considering the audience, but I would still want the fine print (i.e. this article) to explain how the non-technical terms map to technical concepts.

At the least, I would prefer renaming the non-technical terms to be less abstract:

– Primary energy → Gross energy or Raw energy

– Secondary energy → Transportable energy

– Final energy → Delivered energy

– Useful energy (no change)