Abstract Energy efficiency is a powerful measure for promoting sustainability in technological evolution and ensuring feasible battery life of mobile end-user devices. Peer-to-peer technology provides decentralized and self-organizing, but also energy-inefficient technology for distributing content between devices in networks that scale up almost infinitely. The dissertation [1] summarized in this paper makes four contributions towards enabling energy-aware peer-to-peer networking in mobile environments: 1) an empirical study for understanding the energy consumption characteristics of radio interfaces and typical composition of traffic in peer-to-peer networks, 2) a model for estimating the energy consumption of a mobile device with different traffic profiles, 3) a model for energy-aware load monitoring of mobile peer nodes, and 4) a mobile agent based virtual peers concept for energy-aware sharing of peer responsibilities between peer nodes in a subnet. The results give valuable insight into implementing energy-efficient peer-to-peer systems in mobile environments.