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AC/DC

Grid

Solar panel
Battery
HPS2000E

Load

DC AC

Figure 44 – Example of radio site powered by AC main and solar energy
The equipment used to build the ICT infrastructure need to be high efficiency equipment to reduce
their impact and energy consumption respect to their use.

Definition of energy efficiency metrics for ICT is available in ITU‐T Recommendation L.1310 "Energy
efficiency metrics and measurement methods for telecommunication equipment 25 ". This
Recommendation also specifies the principles and concepts of energy efficiency metrics and
measurement methods for small networking equipment used in the home and small enterprise
locations. The Recommendation defines that when transmission time and frequency bandwidth are
fixed, a telecommunication system that can transport more data (in bits) with less energy (in Joules)
is considered to be more energy efficient.
The efficiency of infrastructure equipment is considered in ITU‐T Recommendation L.1320: "Energy
efficiency metrics and measurement for power and cooling equipment for telecommunications and
data centers 26 ". The methodologies defined in this Recommendation are applied at single
equipment level. The efficiency of power conversion and cooling in the data center or
telecommunication facility is only partially attributed to the equipment. The architecture and
organization of the space and equipment to deliver the power or cooling to the systems is an equal,
if not a more significant factor to energy efficiency. Another general factor will be the

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25 Recommendation ITU‐T L.1310 contains the definition of energy efficiency metrics test procedures,
methodologies and measurement profiles required to assess the energy efficiency of telecommunication
equipment. Energy efficiency metrics and measurement methods are defined for telecommunication
network equipment and small networking equipment. These metrics allow for the comparison of
equipment within the same class, e.g., equipment using the same technologies.
26 Recommendation ITU‐T L.1320 contains the general definition of metrics, test procedures, methodologies
and measurement profiles required to assess the energy efficiency of power and cooling equipment for
telecommunications and data centers. More detailed measurement procedures and specifications can be
developed in future related ITU‐T Recommendations. Metrics and measurement methods are defined for
power equipment, alternating current (AC) power feeding equipment (such as AC uninterruptible power
supply (UPS), direct current (DC/AC) inverters), DC power feeding equipment (such as AC/DC rectifiers,
DC/DC converters), solar equipment, wind turbine equipment and fuel cell equipment. In addition, metrics
and measurement methods are defined for cooling equipment such as air conditioning equipment,
outdoor air cooling equipment and heat exchanging cooling equipment.

ITU‐T's Technical Reports and Specifications 271