The physical energy flow accounts record energy flows which circulate in the economy and between the economy and the environment. These flows are grouped into three generic categories: the natural energy inputs (from the environment to the economy) the energy products (inside the economy) and the energy residuals (from the economy mostly to the environment). The PEFA report energy flows following their origin and destination. The origin or the destination of an energy flow is divided into five categories: production by industry (NACE Rev.2 A64), household consumption (heating, transport, other), accumulation, rest of the world and environment. 

The accounts are constructed using the residence principle. This implies totals will differ from the Belgian energy statistics. The latter show energy flows on the Belgian territory, while the PEFA show energy flows caused by Belgian residents, regardless of their geographical position.