Improving the Energy Efficiency of Accelerator Facilities

New particle accelerator based research facilities tend to be much more productive, but often in coincidence with much higher energy consumption. The total energy consumption of mankind is steeply rising, while some European countries decided to terminate nuclear power generation and to switch to renewable energy production. Also the CO2 problem gives rise to new approaches for energy production and in all strategies the efficiency of utilization of electrical energy plays an important role. For the public acceptance of particle accelerator projects it is thus very important to optimize them for best utilization of electrical energy and to show these efforts to funding bodies and to the public. Within the European accelerator development program Eucard-2 we organise a network EnEfficient that aims at improving the energy efficiency of accelerators. In this paper we give some background information on the political situation, we describe the power flow in accelerator facilities and we give examples for developments of efficient accelerator systems, such as magnets, RF generation and beam acceleration, heat recovery and energy management.