PEM Fuel Cells: A reliable, Cost Effective OPTION for OSP ... · PEM FUEL CELLS: A RELIABLE, COST...

PEM FUEL CELLS: A RELIABLE,

COST EFFECTIVE OPTION FOR OSP

BACK UP POWER APPLICATIONS

PEM Fuel Cells – The future is now!

Vito J. Coletto [email protected]

Abstract: If you are looking for an alternative OSP backup power system for your critical loads that can replace batteries & generators, with the lowest total cost of ownership, and zero emissions, PEM fuel cell technology is your solution.

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Vito J. Coletto, Director of Sales 2/22/2015

Table of Contents Background ............................................................................................................................................. 2

VRLA Battery Overview ............................................................................................................................ 2

VRLA Battery Negative Characteristics ..................................................................................................... 3

1. Temperature Sensitivity: .......................................................................................................... 3

2. Battery Cycle Life and Depth of Discharge (DoD): ..................................................................... 4

3. Capacity Loss Due to Continuous Charging/Overcharging: ........................................................ 4

4. Parasitic Self-Discharging Characteristic of VRLA Batteries: ...................................................... 4

5. Number of Charge/Discharge Cycles Leads to Sulfation: ........................................................... 4

6. Cell Tower Failures: .................................................................................................................. 5

7. Continuous Monitoring and On-Going Preventative Maintenance: ........................................... 5

8. Weight/Space Limitations: ....................................................................................................... 6

9. High 10 -15 Year Total Cost of Ownership (TCO): ...................................................................... 6

10. Battery Disposal Costs: ............................................................................................................. 6

Applications Leveraging the Positive Characteristics of VRLA Batteries .................................................... 6

Summary of Battery Technology .............................................................................................................. 7

A Brief History of Fuel Cells ...................................................................................................................... 7

Summary of Fuel Cell Technologies & Applications .................................................................................. 8

PEM Fuel Cells: An Alternative to VRLA Batteries ..................................................................................... 8

What is a PEM Fuel Cell and How Does it Work? ...................................................................................... 9

PEM Fuel Cell Installations ..................................................................................................................... 11

Total Cost of Ownership & Key Industry Attributes Favor Fuel Cells ....................................................... 12

Flexible Fueling Options for Deployed PEM Fuel Cell Sites Nationally ..................................................... 14

Summary ............................................................................................................................................... 15

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Background Although the national utility grid is overall considered reliable, localized conditions and equipment

failures or natural events cause unanticipated outages ranging from minutes to several days. There have

been two major grid failures that were unanticipated just in the last ten years. Most VRLA batteries are

inadequate for the runtime required to meet these extended outages. Table 1 below outlines causes of

large blackouts affecting major population centers. Equipment Failure is the leading cause, followed by

Wind/Rain natural weather events.

VRLA Battery Overview Valve Regulated Lead Acid (VRLA) “deep discharge” batteries have been providing DC back-up power for

Outside Plant (OSP) critical load applications for decades. Among the largest market segments for OSP

applications where VRLA batteries are used extensively for back-up power are Wireless carrier BTS radio

equipment at cell/tower sites nationally and globally; Wireline Remote Terminals - remote Central

Offices (CO) - “Plain Old Telephone Service” (POTS); Cable TV (CATV) distributed power node OSP

cabinets; and traffic signal backup OSP cabinets. Without exception, the most commonly used batteries

for these applications are 12 volt, VRLA type batteries because of their initial cost to power ratio. A

series string of multiple 12 volt batteries will provide the correct DC voltage, typically +24VDC or -

48VDC, and paralleling strings will provide the appropriate amount of current to meet the system load

runtime requirements.

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VRLA batteries were introduced into the marketplace in the 1980’s, as an alternative Flooded Lead Acid

batteries and to address some of their negative characteristics. Manufacturers initially proclaimed that

the long life of the flooded design (approx. 20 years+ if expertly maintained) could be replicated with

the newer technology – VRLA batteries. However, after decades of experience with these batteries,

there are some well documented issues that the industry has come to acknowledge and accept as status

quo.

For several years both end-users and Industry professionals have been asking for another reliable DC

power option that could effectively address the negative characteristics of VRLA batteries, while

complimenting the positive characteristics, in a cost effective manner. Certain critical OSP back-up

power applications within the Wireless and Wireline spectrum that exacerbate the negative

characteristics of VRLA batteries can be effectively addressed with an alternative technology, specifically

Proton Exchange Membrane (PEM) fuel cells, as this paper will document and lay out. To make the case

for fuel cells as a viable alternative, let’s look at the negative characteristics of VRLA batteries that have

been well known and documented.

VRLA Battery Negative Characteristics 1. Temperature Sensitivity: Tens of thousands of OSP cabinets utilize batteries for critical,

uninterruptible DC backup power. Most of these cabinets are non-temperature controlled. The

graph in Figure 2 below illustrates how battery life is affected by temperature rise above the

optimum 77 degrees F:

Based on the equation Actual life = Derate factor x Design Life, a VRLA battery with a design life of

10 years, operating at 85 degrees F, per the graph, will have an actual life of 6.9 years (6.9 = 69% of

10).

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2. Battery Cycle Life and Depth of Discharge (DoD): For deep discharge VBRLA batteries used

in most OSP applications, the graph below illustrates how battery cycle life is reduced with high

percentage Depth of Discharge (DoD) or deep discharge cycles. The graph also shows how

increasing the operating temperature of the battery leads to an increase in the battery aging rate.

3. Capacity Loss Due to Continuous Charging/Overcharging: Because VRLA batteries are the

emergency power source to critical wireless/wireline telecom equipment, they must be always

maintained at full charge. This is accomplished by continuous charging, at a constant voltage,

known as float charging. Continuous charging of deep discharge VRLA batteries at operating

temperatures above 77 degrees F, will result in increased float current at constant voltage which

could lead to overcharging. It has been shown that the capacity of a typical VRLA battery will

decline and eventually the battery will fail due to grid corrosion of the positive plate and drying out

of the battery electrolyte – directly related to excess float current.

4. Parasitic Self-Discharging Characteristic of VRLA Batteries: Because of this characteristic,

VRLA batteries need constant float charging (via the grid), which will result in reduced life due to

corrosion of the positive plate and increased internal battery temperature due to the charging

function. This phenomenon of parasitic self-discharging could occur for low duty cycle stationary

backup power applications, where grid power is stable and reliable, and outages are rare or only last

for seconds or a few minutes.

5. Number of Charge/Discharge Cycles Leads to Sulfation: During normal battery use, small

sulfate crystals form, but these are normal and are not harmful to the battery. During prolonged

charge deprivation (i.e. a Partial State of Charge or (PSOC) application), however, the amorphous

lead sulfate converts to a stable crystalline that deposits on the negative plate of the battery. This

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leads to the development of large crystals, which reduces the battery’s active material and

conductivity. For newer batteries, the lead sulfate is dissolved during the subsequent charging

cycle, however, as the battery ages, the lead sulfate grows into larger crystals that are very difficult

to dissolve, & the resultant problem of sulfation.

o Sulfation also lowers charge acceptance.

o Sulfation also causes longer recharge cycles. Sulfation charging will take longer because of

elevated internal resistance as the sulfate crystal deposits grow larger, which could lead to

premature battery failure.

o See picture below (magnified) showing how the larger lead sulfate crystal form as the

battery discharge/charge cycles increase over time.

6. Cell Tower Failures: Approximately 62 percent of cell tower failures are power related and 80

percent of those are due to battery problems (Source: Battery Power Magazine). A photograph of a

cell tower OSP cabinet that was burned down by a battery fire is shown in the Figure below.

7. Continuous Monitoring and On-Going Preventative Maintenance: Monitoring is required

on a continuous basis to anticipate issues and constantly monitor battery health. This results in

increased annual operating costs, but it is an essential function utilized throughout the industry.

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8. Weight/Space Limitations: As extended runtime requirements are becoming more common

place (8 hours runtime or greater being specified), this results in more batteries/battery strings and

increased weight, along with taking up valuable real estate when placed next to the OSP cabinet

equipment they are intended to power. This limitation applies to ground level deployments where

real estate is at a premium and could result in increased lease space costs. The weight/space

limitation also applies to rooftop deployments, where the extra weight for extended runtime

requirements could result in increased structural support to carry the additional load, driving up

project costs. Available rooftop space is normally at a premium, and battery runtimes of more than

8 hours would not be a practical solution. Many densely populated cities like NYC and SF deploy

rooftop cell towers because of limited space ground level. This is especially true in very densely

populated cities in Asia like Tokyo, Japan. With small cell deployments on rooftops also becoming

more common and on the rise nationally and globally, this limitation on VRLA batteries begs for an

alternative back-up power technology.

9. High 10 -15 Year Total Cost of Ownership (TCO): This results from recurring capital costs to

replace VRLA batteries due to theft (new batteries, shipping costs, installation costs) and replacing

existing batteries every 3 to 5 years for non-environmentally controlled OSP cabinets, and 5 to 7

years for environmentally controlled OSP cabinets. Couple this with continuous monitoring costs

and PM costs noted earlier, VRLA batteries are not an optimum choice for critical OSP back-up

power applications, and will result in a high 10 -15 year TCO.

Battery theft is a growing concern, and telecom providers have seen a spike in battery thefts over

the past few years, given our current economic situation with rampart high unemployment. On a

national scale, this is costing the telecom industry millions of dollars in battery replacement and

increased security costs.

10. Battery Disposal Costs: These are sometimes known as “non-tangible” costs, but they are in fact

real and measurable directly contributing to the high Total Cost of Ownership of VRLA batteries over

a ten to 15 year span. These costs include a certified recycler, documentation, and transportation.

Applications Leveraging the Positive Characteristics of VRLA Batteries VRLA batteries have performed satisfactorily in some OSP applications, as follows:

VRLA batteries housed in an environmentally controlled equipment shelter, OSP cabinet, or

underground Controlled Environment Vault (CEV) maintained at or near 77 degrees F. However, this

results in increased up front capital costs and operating costs to maintain and power these HVAC

systems.

VRLA battery backup for low duty cycle, standby applications (minimum discharge/charge cycles) due to

a generally reliable national utility grid in many locations across the country. This can result in a reduced

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sulfation rate, due to a lower amount of discharge/charge cycles, which should have a positive overall

effect on battery cycle life and performance.

For those applications where only a minimum or 2 to 4 hours of runtime is required, VRLA batteries are

most cost effective, and require minimal footprint for these short runtime applications. However, these

OSPs (telecom & broadband CATV) that house just 2 to 4 hours of runtime do not meet the FCC

mandate of a minimum of 8 hours runtime in the event of an outage. If the FCC mandate is ever fully

enforced, PEM fuel cells will be a logical choice as an alternative technology because it will be shown

that they become more cost effective for extended runtime applications (8 hours or more).

These above applications do no preclude the use of PEM fuel cells. For all of the applications noted

above, fuel cells can also be deployed as a viable option, it is the end-user customer’s choice, weighing

everything in the balance, from technology choices, reliability, and financial value proposition.

Summary of Battery Technology VRLA batteries have been the primary choice for OSP backup power applications for decades and have

performed well some scenarios, as noted above. While battery technology has improved over the years

to address some of the negative characteristics described in the paper, most of these technology

improvements are costly and not field proven: New higher price Lead-Carbon battery technology as

compared to the legacy Lead-Acid batteries, for example. Newer battery technologies have also

resulted in additional negative characteristics, like the increased likelihood of battery fires, shown to be

a real technology challenge with certain expensive Lithium-Ion battery chemistries.

A Brief History of Fuel Cells The origin of fuel cells can be traced as far back as 1776, when the 13 American Colonies declared their

independence from Mother England! A renowned scientist at that time, Henry Cavendish, discovered

that water is not an element, but rather a compound formed when hydrogen reacts with oxygen.

Decades later in 1839, Dr. Christian F. Schönbein hypothesized that this reaction also generated an

electrical current--a hypothesis that Sir William Robert Grove confirmed in 1839 when he experimented

and assembled what he described as a “gas voltaic battery” – what is now known as the first “fuel cell.”

See above figure for his drawing of this experiment. Because of his work in advancing the hypothesis,

Sir William Robert Grove, a Welsh lawyer turned scientist has given the esteemed title: “The Father of

Fuel Cells.” The production of an electric current is by means of an electro-chemical reaction between

hydrogen and oxygen, not the combustion of fossil fuels.

What is today known as a “fuel cell” (a term first coined nearly thirty years after Sir William Grove’s

experiment in 1889, by Charles Langer and Ludwig Mond, to describe their efforts using coal gas) has

now been under development for nearly two centuries.

However, fuel cell technology did not find its first practical uses until the mid to late 1950s, when it

began to be employed for mobile applications that would eventually range from space missions to

public transportation. UTC Power, which was founded in 1959, won the sole-source contract to design

and manufacture fuel cells to NASA. All NASA Apollo & Space Shuttle missions through 2012 included

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two 85kW & 125kW fuel cell modules respectively that provided the astronauts critical power and

drinking water. Although heat is a byproduct of the electro-chemical reaction, the heat for the

astronauts was provided by a different system, not the waste heat from the fuel cells. Can you think of

a more mission critical application for fuel cells then supplying the power and water to help bring

these US astronauts to and from the moon and earth’s orbit safely?

Summary of Fuel Cell Technologies & Applications

In recent years, fuel cells have seen widespread implementation in the USA & and around the world, in

stationary prime power electric only, and combined heat and power (CHP) applications. PEM fuel cell

technology is commercially proven with thousands of deployments, millions of reliable operational

hours, and subjected to wide temperature swings in OSP back-up power applications. PEM fuel cells

have augmented or replaced VRLA batteries systems and totally replaced the diesel generator function

for extended runtime needs.

PEM Fuel Cells: An Alternative to VRLA Batteries Proton Electrolyte Membrane (PEM) fuel cells, like batteries, provide DC electricity without combustion

through an electro-chemical reaction. However, this is where the similarities end. Unlike a battery, the

fuel cell does not need constant recharging to maintain its output voltage. As long as there is a supply of

hydrogen fuel, the fuel cell will produce unlimited runtime with zero emissions at the point of use, which

makes this option excellent for extended utility outages as a replacement for VRLA batteries and diesel

generators.

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What is a PEM Fuel Cell and How Does it Work? A PEM fuel cell produces DC power as a result of a chemical reaction between hydrogen gas and oxygen

from the air, in the presence of a catalyst – without any combustion. See drawing below which

describes each step of the process.

Notes:

Hydrogen is mixed (not burned) with air. This combination, in the presence of a catalyst

converts the hydrogen and oxygen (from the ambient air) to DC electricity and water – with

zero emissions at the point of use, which can support customer sustainability objectives.

Low temperature, fast start times, making the PEM fuel cell ideal for critical CATV back-up

power applications, like distributed/centralized power nodes, wireless telecom, wire line

Remote Terminals (RT) / Central Offices (CO), and traffic signal OSP applications.

No moving parts in cell stack, making for simple and low cost annual preventative maintenance.

PEM fuel cells are modular and scalable from 100W to 100kW to meet the power needs of most back-up

power applications in the four largest OSP market segments mentioned earlier. These compact, solid

state designs address the weight/space limitations of batteries when runtimes of 8 hours or more are

specified.

Also known in the industry as

“Proton Exchange Membrane”

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To illustrate the compact footprint of fuel cell technology, see the picture below for a 10kW OSP

application with 8 hours of fuel storage on-site. These cabinets can be installed next to each other,

minimizing footprint required (see page 11 for example installations):

The Transient Power Module (TPM) or bridge battery is required to provide the 30 seconds of

uninterruptible power to the critical OSP loads while the fuel cell starts. Note that some PEM fuel cell

designs could take 30 minutes or longer to start, which requires a larger bridge battery system, making

them less desirable. If there are existing batteries at a particular OSP installation site they can be used

for short duration outages (seconds to a few minutes), then the TPM is not required. The point is that

an end-user can choose to completely remove all existing system VRLA batteries from a site, and their

associated maintenance costs/recurring capital replacement costs, and replace them with the PEM fuel

cell + small TPM.

For a typical telecom OSP application, the PEM fuel cells DC output connects directly to the system DC,

just like the battery strings, as illustrated below:

PEM Fuel

Cell

Engine

ul

Two 5kW

Fuel Cell

Engines

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Referring to the above diagram, the PEM fuel cell will monitor the DC bus, and upon utility power failure

or rectifier failure, the DC bus voltage will start to decrease. For a typical wireless telecom -48VDC

application, when the DC bus voltage drops from say -54VDC to -52VDC, with thresholds selectable in

0.1VDC increments, the fuel cell with start and power the load for the duration of the outage. When the

utility power returns, the fuel cell monitors and senses the return of the utility, waits until stable, then

returns to a standby mode, waiting for the next outage.

PEM Fuel Cell Installations PEM fuel cells have been installed in thousands of locations nationally & globally, experiencing wide

temperature swings in summer & winter, overcoming the operating temperature (life and capacity)

issues of VRLA batteries. With these thousands of installations, and on-going additional deployments,

PEM fuel cells are a proven, rugged and reliable back up power solution for your critical OSP

applications. Fuel cells are no longer a science experiment or a technology just for niche applications.

Some examples of PEM fuel cell installations at wireless tower/cell sites is are shown below:

Regarding rooftop deployments, besides the weight and space limitations noted earlier for VRLA

batteries, it is difficult to nearly impossible to obtain a permit to operate a diesel or propane generator

on the roof due to potential fuel leaks, pooling on roof surface, and increasing the chances of a

secondary fire. If H2 gas leaks, rather than pool – it is lighter than liquid fossil fuels and the air, it rises at

70 ft/min away from equipment and roof, minimizing the chance of fire at the building structure.

With continued improvements in the supply chain, coupled with significant advances in fuel cell stack

manufacturing, the upfront capital costs of fuel cells, which have been the major issue in the past, have

significantly decreased in the past decade. Rebates & incentives that encourage the use of green and

sustainable technology may be available at the State level and an Investment Tax Credit (ITC) is available

from the federal level providing $3000/kW or 30% of the total project costs, whichever is less. This is a

dollar for dollar reduction in the federal income tax liability for the system owner. No such incentive is

available for battery back-up or generator back-up. This ITC incentive helps narrow the gap in up-front

capital costs between fuel cells and VRLA batteries.

Rooftop application, (L to R) BTS radio

cabinet, PEM fuel cell cabinet, H2 fuel

cabinet. Existing battery cabinet removed, in

favor of the PEM fuel cell + TPM.

Ground level application, (L to R) BTS radio

cabinet, PEM fuel cell cabinet, H2 fuel

cabinet. Existing battery cabinet removed, in

favor of the PEM fuel cell + TPM.

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PEM fuel cells, depending on the design, components used, and manufacturing techniques employed,

have a design life of greater than 10 years, much more than the real life of deep discharge VRLA

batteries, typically 3 to 4 years for most deployed OSP equipment cabinets, which are non-temperature

controlled.

Total Cost of Ownership & Key Industry Attributes Favor Fuel Cells For extended runtime requirements, a typical OSP site (wireless, wire line, CATV, and traffic signal) will

deploy 2 to 8 hours of battery backup in addition to an on-site Appleton connector/manual transfer

switch where a mobile/portable diesel generator can plug into. Some OSP sites have a permanently

installed stationary diesel or propane generator with an Automatic Transfer Switch (ATS) for extended

runtime needs. Due to the high annual operating costs of maintenance for the VRLA battery + diesel

generator combination, in addition to the recurring capital costs of replacing the batteries every three

years or so, it will be shown that PEM fuel cells will provide the lowest 10 year Total Cost of Ownership

(TCO).

As an illustration of the above statements, the graph below shows a typical, generic telecom OSP

application and compares the 10 year TCO of PEM fuel cells to batteries and generators. From review of

this graph, one cannot dispute that PEM fuel cells are an excellent cost effective alternative for your

critical OSP backup power applications and will provide comparable up-front capital costs and the

lowest overall TCO.

5kW PEM Fuel

Cell w/8 hours

runtime

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Notes:

Y axis represents capital and operating costs (OPex) in dollars; X axis represents a ten year look after

initial up front capital investment shown at time “0”. The up-front capital costs for the equipment and

installation are shown for unconditioned batteries in red, conditioned batteries in black, diesel

generator in blue, and finally the PEM fuel cell in green.

The slope of each technology line represent the on-going operating costs and the “jump” every 3 years

for the unconditioned batteries and every 5 years for the conditioned batteries represents recurring

capital costs to replace these VRLA batteries.

For the diesel generator, daily, weekly, monthly, and annual maintenance are required. These costs, as

well as up-front capital costs will be significantly higher going forward due to more stringent EPA

emissions and noise regulations. The other OPex cost element is the cost of diesel fuel + delivery for this

generic scenario.

The PEM fuel cell has no moving parts in the cell stack, and preventative maintenance is simply cleaning

or replacing an air filter once every 1000 hours or one year of operation. The only other OPex cost is the

cost of fuel + delivery, which is much lower than diesel fuel. As you can surmise, the 10 year TCO for the

fuel cell is very compelling compared to VRLA batteries and diesel generators and will provide the best

overall value to the end-user customer.

Another way of illustrating the total value proposition of PEM fuels versus the legacy technologies,

please see the chart below, which list key industry attributes important to end-user customers and

where PEM fuel cells rank compared to VRLA batteries and diesel generators. As you can see, in 8 out of

11 key attributes, the PEM fuel cell is the best technology of choice and best overall value.

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Flexible Fueling Options for Deployed PEM Fuel Cell Sites Nationally Hydrogen gas (H2), the most abundantly used industrial gas nationally, is readily available in most major

cities and localities in the USA. For typical OSP applications, the H2 is stored in steel tanks or cylinders,

and enclosed in a telecom grade OSP cabinet, as shown in the picture above on page 10. Hydrogen has

an excellent safety record for more than 50 years! While hydrogen is a combustible gas, it is been shown

to be safer than traditional fossil fuels like diesel, gasoline, propane, and natural gas.

Re-fueling H2 “Fill” trucks use “Fill-In-Place” technology (FIP) today as a means of re-fueling PEM fuel

cell sites. See pictures below, as an example of FIP technology. The traditional or old method of “bottle

swapping”; having to have access inside the fuel cabinet, disconnecting empty cylinders from the fuel

manifold and connecting full cylinders to the manifold, is no longer necessary. With FIP, where available

nationally, a fill truck fitted with DOT certified hose (see below) connected to H2 large storage cylinders

on the truck, connects to a fill port located on the fuel cabinet door. The hose is simply connected to

the fill port nozzle, and in just minutes, all the cylinders are re-filled in place, with no handling of the

cylinders or access inside the cabinet required. This is a proven, simple, safe, efficient and cost effective

method of providing hydrogen refueling to installed PEM fuel cell system sites, providing “unlimited

runtime” for the end user – something that can never by achieved with VRLA batteries.

Remember, as long as there is a source of H2 fuel, the PEM fuel cell will continuously and reliably

generate the DC output power required for OSP applications, with none of the negative characteristics

or limitations of VRLA batteries itemized earlier in this paper.

For remote locations, with no easy access to H2 gas, propane, or diesel fuel, an extended runtime

solution is still viable with PEM fuel cells using a pre-mixed methanol/water solution and an integrated

steam reformer to generate H2 gas on-site. Several size sealed storage tanks are available and provide

FIP Port

with

Nozzle &

Pressure

Gauge FIP Port, with Small Access Door, Fuel Cabinet View

Fill Hose from

Fill Truck

Typical FIP Capable Fill Truck

Note: Higher storage pressure, composite cylinders

shown above; Aluminum tank, with a carbon-fiber

wrap, they store 2X the amount of H2 gas than the

standard steel cylinders, for longer runtime needs.

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runtimes is days versus hours, and is ideal for remote tower/cell sites, or RT sites, etc. Methanol/Water

reformer systems, like gaseous H2 fueled PEM fuel cell systems, are commercially proven with hundreds

of applications both nationally and globally. The picture below shows an example of an integrated fuel

cell power and H2 generator cabinet.

Summary As this paper illustrated, with unanticipated utility grid failures nationally, VRLA battery performance can

be unpredictable and affected by a wide variety of factors that have been well known for many years,

due to the design characteristics of VRLA batteries. These factors include:

o Charge level

o Ambient/Operating Temperature effects on life and capacity

o Age/Pre-mature failures

o Number of charge/discharge cycles resulting in sulfation

o Weight/space limitations and theft

o Amount of monitoring and on-going maintenance

o Disposal Costs

PEM fuel cells, on the other hand, have been shown to be a more cost effective, scalable, reliable,

extended runtime solution without any of the limitations of batteries and the high maintenance and

environmental issues associated with diesel generators. In thousands of successful installations across

the vertical markets discussed in this paper, PEM fuel cells have met or exceeded requirements and are

a commercially proven technology that should be considered by end-users as a viable alternative to

batteries for OSP back-up power systems.

If you are tired of the issues associated with legacy back up power technologies, and have not looked at

PEM fuel cells recently or at all, I hope this paper has shed new light on this clean, reliable, cost effective

alternative back up power technology, for serious consideration at existing sites where there are

planned battery or generator replacements or for new OSP sites being considered.

Sealed Methanol/Water

Storage Tank

H2 Generator

2.5kW or 5kW

Fuel Cell

Engine

Fill Port Access

for Refills

48” W x 41” D x 72” H

PEM Fuel Cells: A reliable, Cost Effective OPTION for OSP ... · PEM FUEL CELLS: A RELIABLE, COST...

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