In this work, we derive a distributed power control algorithmfor energy-efficient uplink transmissions in interferencelimitedcellular networks, equipped with either multiple orshared relays. The proposed solution is derived by modelingthe mobile terminals as utility-driven rational agents thatengage in a noncooperative game, under minimum-rate constraints.The theoretical analysis of the game equilibrium isused to compare the performance of the two different cellulararchitectures. Extensive simulations show that the sharedrelay concept outperforms the distributed one in terms ofenergy efficiency in most network configurations.