In heterogeneous networks (HetNets) system, the exploitation of small cells (SCs) will be enhanced spectral efficiency that means guarantee QoS and coverage area to user terminals. We propose a joint linear precoder designproblem to maximize the energy efficiency of the HetNet model. To tackle the cross-tier interference in the HetNets, we exploit zero-forcing precoding where the interference at the users is cancelled out by block diagonalization scheme. A novel group sparsity promoted as group Lasso is proposed using the weighted ℓ1 norm minimization, where the group sparsity pattern indicates those SCs that can be switched off and non-associated users. Simulation results show that the proposed algorithm outperforms many existing algorithms in terms of the total energy efficiency in the HetNets.