Cellular networks are evolving from traditional homogeneous networks to heterogeneous network (HetNet) to cope with the ever-increasing traffic growth and users' expectations. This new paradigm not only offers a significant improvement in the network capacity and user data rate but also promises improvement in overall network energy efficiency (EE). To achieve these improvements however, radio resources need to be utilized in a coordinated manner to ensure adequate users' satisfaction level. This paper proposes a new energy aware methodology for evaluating the EE in HetNet. In particularly, it analyzes the impacts of HetNet resource coordination (HetRC) on the overall EE. HetRC offers valuable insights on how to optimize different combinations of main systems parameters such as frequency band, modulation and coding scheme, and channel bandwidth size towards better EE. The simulation results show that the proposed HetRC has a significant impact on HetNet's EE performance and hence gives a fresh direction towards EE improvement in future HetNet.