White Paper
Advanced Fuel Cells—A Reliable and
Green Solution to Reduce Operating
Expenses of Telecommunication
Networks
Anil K. Trehan, Vice President, Energy Solutions – CommScope, Inc.
May 28, 2013
Contents
Executive Summary
3
Fuel Cells
3
Advanced Fuel Cell Solution for Telecommunications Networks
3
Key Features of the Advanced Fuel Cell Solution
5
Global Field Installations and Results
6
Asia Field Installation
7
Europe Field Installation
9
North America Field Installation
10
Key Observations
11
Conclusion11
2
Executive Summary
Telecom networks require significant energy to operate. Even though energy prices are
presently at relatively reasonable levels, the operators are trying to reduce the energy
consumption of their networks. There are several factors behind this focus. For example, energy
bills contribute to more than half the operating cost of the network. In addition, lower energy
usage is an effective way for operators to minimize their environmental impact, reduce carbon
footprint and use more sustainable forms of energy.
Since telecom networks typically have tens of thousands of sites, operators must reduce
operational and maintenance costs to compete effectively. Operators around the world are
exploring applications of alternate energy solutions in their networks. Solar arrays, wind turbines
and fuel cells have all been implemented in various telecom applications with varying degrees
of success. These solutions have higher initial costs but offer significantly lower costs of operation
and maintenance with substantially lower carbon footprint. The options for reducing costs and
the environmental impact of running a network are not only good for the environment; they
also make excellent business sense for operators and support sustainable, profitable business.
Some governments, such as the United States, are even offering tax incentives to help foster the
adoption of these technologies. This paper provides evidence that hydrogen fuel cell back-up
power systems are not only reliable and green, but result in real operating expense reduction.
Fuel Cells
Fuel cells are electrochemical devices that convert chemical energy in fuels into electrical
energy directly, thereby generating power with high efficiency and low environmental impact.
There are a variety of different types of fuel cells. This paper focuses on the Proton Exchange
Membrane (PEM) fuel cell which utilizes hydrogen as a fuel. PEM fuel cells are best suited
for backup power applications as they provide high power densities and operate at low
temperatures (60 to 80°C), which allows them to startup faster than other fuel cells.
Typically, backup power for telecommucation sites is provided by lead-acid batteries and diesel
generators, which have considerable environmental impact. Fuel cells provide an eco-friendly
backup power solution as the only byproducts are heat and water. They are efficient, reliable,
quiet, and designed to last a long time.
Advanced Fuel Cell Solution for Telecommunications
Networks
Wireline and wireless telecom networks have a wide range of power loads and an extensive
set of compliance requirements. The CommScope solution incorporates a compact fuel cell
solution in an enclosure, which has been deployed over the past 6 years with other active
electronics in the outside plant for several other applications by leading telecommunication
companies. The combination of existing industry knowledge and numerous field deployments
was instrumental in development of this highly reliable solution for outdoor power backup
applications.
3
Figure 1 illustrates a 8-kilowatt fuel cell module housed in a 63-inch (H) x 45-inch (W) x
52-inch (D) cabinet, which is Telcordia GR-487 compliant. The cabinet contains all necessary
power conditioning equipment for providing regulated DC Voltage to match site requirements,
typically at battery float voltage. The system provides instantaneous power upon loss of AC or
DC power using a small bridge battery located in the battery compartment of the cabinet.
Figure 1
The equipment stack in the cabinet from the top to the bottom includes the following:
1.AC to DC Rectifier, used to provide primary power when grid electricity is available
2.Overall System Controller (OSC)
3.A Power Conditioning Modules (PCM) – a DC-DC converter, which provides regulated
voltage to load
4.Wireless Radio and Microwave backhaul equipment
5.An 8-kilowatt Fuel Cell Power Module (FCPM) – Proton Exchange Membrane (PEM) based
hydrogen fuel cells
In addition, the cabinet has a DC distribution panel with breakers for connecting the DC load,
the PCM and bridge batteries. The OSC provides the necessary means to detect loss of AC or
DC power in order to turn on the FCPM for providing power when needed. The PCM’s prime
function is to take unregulated DC voltage from the FCPM stack and convert to a steady-state
DC voltage as required by the telecommunications application. Typically 54 volts of direct
current (VDC) is provided with a +/- 0.5 volt variance. The system operates in a hydrogen fail
safe mode in accordance with ANSI/CSA FC-1 requirements. The OSC also provides a series
of alarms such as open door intrusion, power major/minor and other alarms along with those
specific to fuel cell technology. In addition, the OSC controls the time necessary to purge five
volumes of air from the system, per the FC-1 requirement. This purging operation followed by
turn up of the FCPM to full power is about 90 seconds.
4
The cabinet equipment configuration discussed above is recommended for new site installations
or for sites where the existing radio equipment can be accommodated in the fuel cell cabinet to
reduce the overall site footprint and power consumption. For existing sites, the fuel cell cabinet
can also be installed with only the fuel equipment in the cabinet, and it can interface with the
existing power supply, batteries, and radio equipment located in other cabinets or shelter on
the site.
Key Features of the Advanced Fuel Cell Solution
The following list highlights the key features of the solution:
•No monthly start up requirement
•Unlimited start/stop capability
•Industry leading fuel cell efficiency
•Patented Dry/Dry Operation – No humidification required for the hydrogen or air feed to the
fuel cell
•Highest power density in the industry
•Single footprint capable of accommodating electronics in the cabinet, which houses the fuel cell
•Power conditioning with a range from -42 VDC to -58 VDC, which matches most
telecommunication sites. Typically these sites are set at battery float voltage around -54 VDC.
•Design in accordance with ANSI/CSA FC-1, CE and Telcordia requirements
•All aspects pertaining to the proper and safe handling of hydrogen fuel source.
•A system controller capable of maintaining all aspects relating to fuel cell operation and
safety as well as providing all Telco required alarms
•Cabinet thermal systems and controls required to meet Telcordia -40°C to +46°C ambient
temperature conditions
•Cabinet ventilation controls required to operate the fuel cell to their maximum efficiency
•Electrical system including bridging power in order to ensure no loss of DC power to the site
load during an AC power outage
The hydrogen to the fuel cell cabinet is provided by hydrogen cylinders stored in a hydrogen
storage cabinet (Figure 2), which has the capacity to store 16 standard hydrogen cylinders.
The hydrogen cylinders are configured in two banks of eight with an automatic switch-over
from one bank to another. This cabinet includes the pressure regulator, manifold, flexible hoses,
check valves and safety relief valve. The storage cabinet can be placed next to the fuel cell
cabinet or located away from it for hydrogen logistics reasons. The hydrogen pressure of each
bank is continuously monitored and an automatic email can be issued when it reaches a preset
threshold. This feature allows notification to the hydrogen distributor for refueling the cylinders in
the cabinet.
5
Figure 2
All aspects of the fuel cell operation are monitored by the system controller and can
be communicated remotely using an Ethernet connection or a wireless modem.
Several alarms are also reported by the system controller. Following is a partial list of
these alarms:
•Door Open Alarm
•Ventilation Fan Alarm
•DC Power Major and Minor Alarms
•AC Fail Alarm
•Battery on Discharge
•Ambient Temperature (Internal and External)
•Hydrogen Storage Pressure for each Bank
•Cabinet Low Temperature Alarm
•FCPM Major and Minor Fail Alarm
Data collected through remote fuel cell activation or as gathered when actual power outages
occurred can be used to evaluate the reliability and durability of the fuel cell.
Global Field Installations and Results
The fuel cell solution was installed in various configurations at several locations around the
world to test the operational reliability and durability of the system in different climate conditions
with varying quality of power grids. These deployments ranged from outdoor and indoor
wireless cell sites to wireline huts and shelters in Asia, Europe and North America.
6
Asia Field Installation
Figure 3 illustrates an application on a cell site in an emerging wireless market in Asia. The
existing backup power solution on this site included several strings of lead acid batteries and a
diesel generator. The site has numerous power outages every day and considerable amount of
diesel fuel is consumed, thereby creating significant air pollution. In addition, diesel pilferage is
rampant, which increases the cost of operating the site.
Figure 3
The fuel cell and the hydrogen storage cabinets were placed next to each other on an existing
concrete pad on this site. The DC bus of the wireless site was connected to DC distribution panel
in the fuel cell cabinet. The system controller monitored and recorded data on all aspects of the
fuel cell operation. The data was transmitted remotely through a wireless GPRS modem. This site
experienced frequent power outages and as such the fuel cell operated each day to provide
power. The daily power outages ranged from as low as 15 minutes to as high as 17 hours. The
fuel cell provided the required power load and kept the wireless cell site operational at all times.
The system monitored the hydrogen fuel consumption at the site and generated automatic e-mail
for the local hydrogen distributor to schedule hydrogen delivery on the site. This notification
scheme worked very well in ensuring timely delivery of the hydrogen to the site. Figure 4
depicts the power outage on this wireless cell site for a 50-day period, during which there
were 235 outages. The fuel cell supported all the outages and operated for a cumulative time
period of 126 hours.
Figure 4
7
Another installation in Asia was on a cell site shared by several wireless operators and owned
by a tower company. Figure 5 illustrates this application. The fuel cell provided backup
power for two operators on this site. The DC bus for the wireless operators was tied to the DC
distribution panel in the cabinet. This site also experienced frequent power outages and the
fuel cell provided backup power during all outages. The setup of this installation was similar
to the one described above with respect to monitoring and data collection. Figure 6 depicts
the power outage on this wireless cell site for a 30-day period, during which there were 48
outages. The fuel cell supported all the outages and operated for a cumulative period of 31
hours. The ambient temperature during these operational periods at these sites was about
45ºC. Both of these field installations have demonstrated the high reliability and durability of
the fuel cell cabinets in providing backup power.
Figure 5
Figure 6
8
Europe Field Installation
Figure 7 illustrates the deployment of the fuel cell cabinet on a wireless cell site in Europe.
Prior to this deployment, the BTS equipment on the site was housed in a shelter with an airconditioner, which consumed considerable amount of power. The shelter was removed from
the site and all equipment in it accommodated in the fuel cell cabinet within 6 hours. The site
footprint was reduced by over 50 percent and the energy consumption was reduced as the
air-conditioner was eliminated. This site is located in a remote area in Eastern Europe and
it experiences several utility outages. Figure 8 depicts the power outages on this site for a
6-month period, during which there were 82 outages, which ranged from a few minutes to up
to 8 hours. The fuel cell supported all the outages and operated for a cumulative time period of
over 56 hours. This fuel cell controller on site is connected to a GPRS modem and the wireless
operator can remotely log in to monitor all aspects of the fuel cell operation. Contrary to the
initial perception, hydrogen delivery to the site was not an issue.
Figure 7
Figure 8
9
North America Field Installation
Figure 9 illustrates the deployment of the fuel cell cabinet outside the headquarters of the
Society of Cable Telecommunication Engineers in Exton, PA. This building has solar panels on
the roof, which are connected to an inverter to provide AC power. When required, the AC
power from the inverter provides backup power to the data center located in the building.
Otherwise it offsets the AC load in the building. In this installation, the fuel cell was tied to the
DC side of the solar power system. The fuel cell operates when there is an AC outage and
the solar panels can’t provide the power required, because either it is nighttime or there isn’t
enough solar irradiance due to cloud cover. This office building has few power outages during
a given year.
Figure 9
During Hurricane Irene, the office building had an 18-hour power outage. The fuel cell
provided the backup power during this period. The office building has recently experienced
other power outages due to bad weather in the area and the fuel cell has supported all these
power outages.
10
Key Observations
The field installations in various parts of the world, and with different equipment configurations,
have demonstrated that the advanced fuel cell solution provides a reliable and cost-competitive
means of providing backup power. A summary of the key observations from these field
installations is listed below:
•The fuel cell operated in diverse environments with 100 percent availability
•Average maintenance costs were reduced by 77 percent and average operational costs
were reduced by 37 percent
•On average, the footprint space was reduced by 50 percent
•Real time remote monitoring of power backup reduced truck rolls
•Hydrogen is widely available and misconceptions about safety easily were dispelled after
installation and operational experience
Conclusion
The fuel cell application, in various geographical locations around the world and in different
equipment configurations, has demonstrated that it is a highly reliable, durable and costcompetitive solution. Several telecommunications companies around the world have started
to evaluate the fuel cell technology for backup power. Some governments and agencies are
providing incentives to help companies embrace this environmentally friendly technology and
deploy it in significant volumes.
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This document is for planning purposes only and is not intended to modify or supplement any specifications or warranties relating to CommScope products or services.
WP-104050.3 EN (06/13)
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