Solar Power Supply Solutions For Telecom Base Station
With more than six billion subscribers, the cellular networking and
communications industry is growing rapidly. To support this growth
in the subscriber base, cellular operators have expanded their
coverage and capacity by deploying additional network
infrastructure. This in turn has increased the energy consumption
of cellular networks and their contribution to greenhouse gas
emissions. With more than three million
base stations (BSs) worldwide, cellular networks currently
contribute to around 3% of the worldwide energy consumption and 2%
of carbon emissions . Also, it is predicted that the carbon
emissions of information and communication technologies (ICT) will
increase from 170 metric-tons in 2014 to 235 metric-tons by 2020.
This increase in the power consumption and carbon footprint of
cellular networks has
led to various initiatives for “green” solutions from telecom
providers, government agencies and researcher.
One of the key components of a cellular network is the base
station. BSs are categorized according to their power consumption
in descending order as: macro, micro, mini and femto. Among these,
macro base stations are the primary ones in terms of deployment and
have power consumption ranging from 0.5 to 2 kW. BSs consume around
60% of the
overall power consumption in cellular networks. Thus one of the
most promising solutions for green cellular networks is BSs that
are powered by solar energy. Base stations that are powered by
energy harvested from solar radiation not only reduce the carbon
footprint of cellular networks, they can also be implemented with
lower capital cost as compared to those using grid or conventional
sources of energy.
Generally speaking, remote area power system consists of
electricity generation, energy store, energy conversion, and
management equipment. Energy generation equipment includes diesel
generator, photovoltaic array, wind generator and hydraulic
generator. Storage equipment includes battery pack and energy
storage bank. Energy conversion and management equipment comprises
DC converter and inverter switch.
Diesel generator is the main power supply in remote areas. It is
necessary to keep the load at 60-70% of rated capacity to maximize
fuel efficiency and reduce maintenance. The wind generator can
reach 250W-500kW output; however, steady wind fields are required.
Likewise, suitable and stable river current is a must for hydraulic
generator. Furthermore, the hydraulic generator is expensive even
though the operating cost is relatively low.
