Flow of energy refers only to energy from diferent sources including sun, electricity, petrol, foodstuff, etc as long you can determine its energy contents. Of course several nutrients, for animals i.e, have energy, while others, as minerals, has not.
The flow of energy is unidirectional and involves a linear pathway, while the flow of nutrients is cyclical and involves a recycling process within the ecosystem. Both processes are crucial for the functioning and sustainability of ecological systems