This article explores the average controllability of composite networks generated by factor networks via Cartesian product from energy control perspective, which can be characterized by the controllability Gramian-based metrics. The considered factors are directed weighted networks with diagonalizable / non-diagonalizbable Laplacian dynamics. It is shown that the average controllability of a composite network is determined by the spectral properties of its factors without calculating its own high-dimensional matrix, which reveals how the energy-related controllability of a Cartesian product network (CPN) can be derived from its factors’ features. This will reduce the computational complexity and provide insights to study the energy control of other graph product networks.