This document provides the methodology to be used by vendors and third party independent laboratories in the formation of a Telecommunications Energy Efficiency Ratio (TEER). The requirements and definitions in this document are for DC power plant rectifiers that are deployed in the telecommunications industry. This standard represents one part of the larger ATIS suite of standards concerning Telecommunications Energy Efficiency (ATIS-0600015.xx.2009). This standard (ATIS-0600015.04.2009) specifically addresses DC Power plant rectifiers and is to be used in conjunction with ATIS-0600015.2009. Purpose This document provides a set of definitions@ requirements@ and guidelines for calculating the Telecommunications Energy Efficiency Ratio (TEER) of DC Power plant rectifier products. The test methodology employed to verify the power consumption@ used as part the TEER calculation@ is specific to power equipment and therefore differs from ATIS-0600015.2009. Application This document (and supporting documentation) is intended to be used by communication network operators@ equipment manufacturers@ suppliers@ and test laboratories as a standard method for determining the energy efficiency of DC Power plant rectifiers. By comparing the TEER reports of various products@ a communications network operator can select equipment that meets their energy efficiency target.