The cement industry is one of the most energy intensive industries, with energy representing 30 to 40% of production costs. This gives energy efficiency improvement an important role in reducing production costs. The energy consumption in the US cement industry has decreased over past decades, although more recently energy consumption seems to have stabilized. Between 1970 and 1999 primary physical energy intensity for cement production dropped 1%/year from8.5 to 6.2 GJ/ton. Carbon dioxide emission intensity from fuel combustion and raw meal calcinations dropped 16%, from 310 kg C/ton to 260 kg C/ton . The still relatively high share of wet-process plants suggests the existence of a considerable potential for energy efficiency improvement, when compared to other industrialized countries. In part 2 of this article, more than 40 efficient technologies, measures and possibilities for energy savings will be described, with reference to carbon dioxide savings, investment and operation costs.