Distributed antenna systems (DAS) are known to improve coverage and performance of wireless communications in indoor environments.In this paper, the power consumption and energy efficiency of a DAS using radio over fiber (RoF) are evaluated and compared with those in a centralized antenna system. The instantaneous power consumption curves of a Wi-Fi access point and dongle combination are physically measured for different transmission configurations, yielding a distance-dependent energy efficiency model. In a second step, computer simulations show that a distributed system with four antennas is 3.8 times more energy-efficient than a centralized antenna system, while the total radiated power is divided by a factor of two.