Green Manufacturing of Electricity Using SOFC Based

Bloom Energy Server TM

Shaishav R. Pandya, Vatsal M. Shah, Soham D. Shah

Abstract— The need for manufacturing and generation of

electricity in a cheap, clean and ‘green’ way is a must in an

eco-friendly society. Bloom Energy Server is one of the

best possible solutions. The heart of it is patented solid-

oxide fuel cell (SOFC). The basic principle of its working

is reverse electrolysis. The cells can run on a variety of

fuels, including traditional fuel, natural gas, biomass gas,

landfill gas, and ethanol. It produces enough energy so as

to power 100 average households or 30,000 sq.ft. office. It

has a very good scope in India where electricity is costly

and also not readily available. Bloom Energy Server is

cheap (when compared with avg. Indian commercial and

residential electricity cost) and reduces carbon emissions

by 60 to 100%. This paper further discusses the amount

which we can save by using it and the role our government

can play to make its usage even more cost effective.

Keywords— Distributed power generation (DG), solid-

oxide fuel cell, Energy Server TM, Environment.

I. INTRODUCTION

Bloom Energy Server is an innovative concept in

distributed power generation technology to produce

electricity. Bloom-Energy, a start up based in

Silicon Valley led by K.R. Sridhar has come up

with Bloom's Energy Server, a clean, reliable and

affordable electricity generator at the customer site.

He introduced it as “It’s the plug and play future of

electricity.”

Bloom Energy is a provider of breakthrough solid

oxide fuel cell technology that generates clean,

highly-efficient power onsite from a wide variety of

fuel sources. Bloom Energy’s mission is to make

clean, reliable energy affordable for everyone in the

world. The Bloom Energy Server is currently

producing power for several Fortune 500

companies. The company is headquartered in

Sunnyvale, CA..Each Bloom Box provides 100-

200kW of power, enough to meet the base load

needs of 100 average homes(900 kWh/house) or a

30,000 sqft. office building, day and night, in

roughly the footprint of a standard parking space.

[4][1] For more power, simply add more energy

servers. They use solid oxide fuel cells to convert

fuel into electricity through a clean reverse

electrolysis process rather than pollution-causing

combustion.

This paper is organized as follows. In Section II

and III, fuel cell and SOFC is described in detail.

Section IV describes the architecture of Bloom

Energy Server. Energy Server is compared with

solar and wind generators in Section V. Its

customers, benefits and applications are discussed

in Section VI. Its scope in India and the role which

the government of India can play is discussed in

section VII.

II. FUEL CELL

A fuel cell is a device which converts chemical

energy of a fuel to electrical energy through

chemical reaction with oxygen or any other

oxidizing agent. Fuel cells primarily use hydrogen

as fuel, but nowadays fuel cell working on ethanol;

biogas and natural are also available.

A. Construction and working of fuel cell

In such cells, hydrogen and oxygen gases are

bubbled into the concentrated aqueous solution of

an alkali like sodium hydroxide or potassium

hydroxide through the porous carbon electrodes,

which contain small catalyst like platinum.

Hydrogen is fed into anode compartment, where it

is oxidized. Oxygen is fed into cathode

compartment, where it is reduced. The diffusion

rates of these gases are carefully regulated to get

maximum efficiency.

Working of it is shown schematically in Fig. 1 and

reactions taking place at anode and cathode are:

Anode reaction: 2H2 (g) + 4OH-(aq) 4H2O (l) +4e

-

Cathode reaction: O2 (g) + 2H2O (l) + 4e- 4OH

-(aq)

_______________________________________

Net reaction: 2H2 (g) + O2 (g) 2H2O (l)

The cell runs continuously as long as the reactants

are fed into it. The voltage of such cells is about

1.2V.

Fig 1. Working of a H2-O2 fuel cell.

B. Uses and Advantages

Uses of this cell are that they can be used to

generate electricity continuously and they were

used for electric power in the Apollo space

programme. [8]

Advantages of fuel cells are:

1. High efficiency: The fuel cells convert

chemical energy of fuels directly into

electrical energy and hence are more efficient

than conventional methods.

2. Continuous source of energy: In this cell,

there are no electrode materials to be replaced.

Fuel can be fed continuously to produce

power and that is the reason why they are

used in space-crafts.

3. Pollution free working: In this cell, no

objectionable by-products are produced and

therefore they do not cause any pollution

problems.

III. SOLID-OXIDE FUEL CELLS

Solid-oxide fuel cells like the name suggests are

characterized by a solid-oxide or a ceramic type

electrode material. Advantages of this class of fuel

cells include high efficiency, long-term stability,

fuel flexibility, low emissions, and relatively low

cost. Low cost is possible because such fuel cells do

not use any noble metal like platinum for catalytic

actions, but the high temperature itself eases the

reaction rate. The largest disadvantage is the high

operating temperature which results in longer start-

up time.

SOFCs operate at extremely high temperature

(typically above 800°C). This high temperature

gives them extremely high electrical efficiencies,

and fuel flexibility, both of which contribute to

better economics. Also SOFCs have a potential

long life expectancy of more than 40000–80000 hr.

[9}

A. Construction of SOFC

In Bloom’s SOFC, the electrolyte is a solid

ceramic square made from a common sand-like

"powder”. A fuel cell is like a battery that always

runs. It consists of three parts: an electrolyte, an

anode, and a cathode. The anode and cathode are as

shown in Fig. 2.

Fig 2. Bloom Box SOFC, black is cathode and green is anode.

Source: Bloom Energy Server Website.

For a solid oxide fuel cell, the electrolyte is a

solid ceramic material. According to Bloom’s

patent description, these thin white ceramic plates

are Scandia stabilized Zirconia (ScSZ).The anode

and cathode are made from special inks that coat

the electrolyte. One side of the ceramic electrolyte

plate is coated with a green nickel oxide-based ink

that works as an anode; the other side, which works

as a cathode, is coated with black ink (Lanthanum

Strontium Manganite). The Bloom server does not

require chemicals, such as the corrosive acids used

in conventional fuel cells. Instead, it uses

inexpensive metal alloy plates for electric

conductance between the two ceramic fast-ion

conductor plates, as opposed to the use of costly

precious metals like gold or platinum that is used

for high conductance in other fuel cells.[6][4][9]

B. Working of SOFC

An electrochemical reaction converts fuel and air

into electricity without combustion. SOFC requires

a high operating temperature (600-1000oC) for its

reactions to take place. The working is shown in

Fig. 4. At a high temperature, warm air enters the

cathode side of the fuel cell. The resulting steam

mixes with the fuel to produce reformed fuel; this

reformed fuel enters the anode side, and a chemical

reaction takes place.

Fig.3 Cross section of the three ceramic layers of an SOFC. From left

to right: porous cathode, dense electrolyte, porous anode. Source:

www.wikipedia.com

Next, the chemical reaction begins in the fuel cell.

As the reformed fuel crosses the anode, it attracts

oxygen ions from the cathode. The oxygen ions

combine with the reformed fuel to produce

electricity, water, and small amounts of carbon

dioxide. The water gets recycled to produce the

steam needed to reform the fuel. The process also

generates the heat required by the fuel cell. As long

as there's fuel, air, and heat, the process continues

producing clean, reliable, affordable energy. [2][3][5]

Anode Reaction: 2 CH3OH+2H2O→2CO2+12H++

12e-

Cathode Reaction: 3O2+ 12H+ + 12e

- → 6H2O

_________________________________________

Overall Reaction: 2CH3OH + 3O2→ 2CO2 + 4H2O

+ 12 e-

C. Power Output of SOFC

Each plate of a SOFC produces about twenty five

Fig. 4. How a Solid oxide Fuel Cell Works. Source: Bloom Energy Server

Website

watts of power. The plates are stacked together until

the total power produced is one hundred kilowatts.

This means about 4000 plates have to be stacked

together.

IV. ENERGY SERVER ARCHITECTURE

Every bloom energy cell basically is made by the

solid oxide fuel cell technology (As explained

above).

Each energy server consists of thousands of

Bloom energy cells. Each cell is a flat solid ceramic

square made from a common sand-like "powder."

Each Bloom Energy fuel cell is capable of

producing about 25W, enough to power a light bulb.

For more power, the cells are sandwiched; along

with metal interconnect plates into a fuel cell

"stack". A few stacks, together about the size of a

loaf of bread, are enough to power an average home.

The output from the fuel cell is naturally in the

form of direct current (DC), but as most technology

is built to run on alternating current (AC) the

Fig 5. Internal structure of Bloom Box. Source: Bloom Energy Server

Each energy server has multiple stacks aggregated

together into a "power module",

Multiple power modules, along with a common

fuel input and electrical output are assembled as a

complete system as shown on Fig. 5.

Fig 6. Architectural diagram of Bloom Box. Source: CNET news.

Energy Server comes with the necessary conversion

to 480 volts three phase AC. 480V is typically

delivered on local transmission lines; a 4-to-1

transformer can be used to step down this voltage to

120V with minimal losses if needed.

Thus, multiple Energy Server systems can be

deployed side by side. When more power is

required—for example, for commercial or industrial

sites—multiple Energy Server systems can be

deployed side by side. The current Energy Server in

the market has the capacity to generate 100kW of

electricity, which would power a 30,000 sq. ft.

office building or 100 average-sized U.S. homes. [4]

The above explained architecture of Bloom box in

shown in Fig. 6.

The modular architecture also ensures,

1. Easy and fast deployment

2. Inherent redundancy for fault tolerance

3. High availability (one power module can be

serviced while all others continue to operate)

4. Mobility.

V. COMPARISON OF BLOOM ENERGY SERVER WITH

SOLAR AND WIND GENERATORS

The advantages and disadvantages of Bloom

Energy Server over solar and wind generators are

listed as below:

1) Energy costs: The Bloom server will produce

power for nine to 10 cents per kilowatt hour

after incentives (California offers a $2,500 per

kilowatt subsidy. And then there’s the 30

percent US federal government tax credit and

without incentives 16 cents max). Commercial

solar installations, when incentives and external

costs are added, generate power for around 10

cents a kilowatt hour. But Residential solar

generates power for around 19 cents a kilowatt

hour and utility-scale solar costs around 11

cents a kilowatt hour. Cutting edge wind

turbines can generate power for five cents a

kilowatt hour after incentives, according to the

American Wind Energy Association. Wind wins

this contest and solar and Bloom are about tied.

Bloom server buyers will have to contend with

fluctuating gas prices: The box does not work if

you don’t put gas into it. If methane and biogas

rise in price, so will the cost of running the box.

Buyers, however, can likely insulate themselves

with long-term gas contracts.

2) Maintenance: Solar panels require a minimum

of maintenance. Dust them occasionally and

wipe off the snow and you are done. Bloom

servers will be monitored closely by their initial

buyers. The servers also contain fans and other

mechanical objects. More handholding and

repairs seem inevitable. One of the big hurdles

that Bloom will have to leap is the reliability of

the ceramic/zirconium plates inside the fuel cell.

These plates, which convert gas to electricity,

must operate in an 800-degree Celsius

environment without becoming distorted or

corrupted. User data will be heavily scrutinized.

Sources say that the plates have a lifetime of

five years: replacement at this pace is

contemplated at nine to 10 cents a kilowatt hour

price. If replacement occurs at a faster rate, it

could throw off the costs.

3) Warranty: Solar systems have warranties that

last 20 years or more. Bloom currently offers a

10 year warranty.

4) Testing and certification: Solar and wind both

have an advantage here. Underwriters’

Laboratory and hundreds of utilities have tested

and tinkered with photovoltaic panels and wind

turbines for years. Getting a solar field

approved mostly revolves around obtaining

financing. Bloom will have to go through the

proctology exam of utility reliability testing.

That could take a few years. On the other hand,

if Bloom passes these tests well, sales will

zoom.

5) Carbon emissions: It takes about four years to

work off the carbon footprint of a solar panel.

The Bloom server continually emits carbon

dioxide. But the Bloom server emits about half

of the carbon dioxide that would be generated if

you bought power from a power plant.

Consumers can reduce their carbon footprint to

almost zero by stoking the box with biogas.

Bloom’s patents discuss converting the waste

carbon dioxide into a methane-like fuel by

running the carbon dioxide through the fuel cell

and adding water. It’s a fascinating, but

extremely challenging idea, but bloom is

working on it. Bloom thus represents a step

forward compared to power plants.

6) Power availability: This is Bloom’s biggest

selling point. The box can produce power 24

hours a day in a completely predictably fashion.

Solar panels only produce during the day and

wind turbines are only active about 30 percent

of the time. Worse, wind turbines in many areas

generate most of their power at night.

7) Storage: Bloom has an advantage over solar and

wind generators. Fuel cells are by their very

nature electricity-storage devices. Power

doesn’t get made until gas gets released into the

fuel cell stack. General Electric and others are

trying to build sodium or lithium battery packs

to store power at wind and solar fields but these

are in the experimental stage.

8) Competition: Bloom will have to face an array

of competitors: General Electric, Siemens,

Philips, Areva, you name it. The relatively

small company will have to run fast to stay

ahead of industrial giants or face getting

acquired. Solar and wind have already gone

through this process. Solar and wind companies

again can also license ideas and leverage

partnerships. Bloom right now is sort of on its

own.

9) Manufacturing footprint: The solar industry

continues to work off a glut of excess factory

capacity, whereas Bloom needs to build up.

Solar wins for now, but for painful reasons.

Although Bloom has raised around $400

million, it will need to raise more to build up

factory capacity. As other companies have

found, finding financing still remains tough.[6]

Thus, we can see that Bloom Energy Servers have

clearly a leading edge when compared with solar

and wind generators.

VI. CUSTOMERS, BENEFITS AND APPLICATIONS

Bloom Energy Server costs between $700,000

and $800,000, and pays for itself in three to 5 years

based on an energy cost of 8 to 9 cents per kW hour.

Bloom Energy Servers are currently in use by a

few notable companies who have agreed to test the

technology. Google, a company known to be on the

forefront off technology themselves, was their very

first customer. Four units of Bloom Boxes have

been powering Google’s data centres since July

2008. Since Google signed on with Bloom Energy,

quite a few other large corporations have readily

joined the project, including Coca-Cola, eBay;

Bank of America, FedEx, and Wal-Mart, by

installing 500kWh Bloom Boxes each. EBay's CEO

John Donahue said that the five Bloom Boxes

installed on his campus in 9 months ago had saved

the company more than $100,000 in electricity

costs.

Bloom Energy's versatile fuel cell technology is

essentially a flexible energy platform, providing

multiple benefits simultaneously for a wide range of

applications.

In addition to clean, reliable, affordable

electricity, Bloom customers can realize a multitude

of other advantages:

1) Carbon Sequestration: The electrochemical

reaction occurring within Bloom Energy

systems generates electricity, heat, some H2O,

and pure CO2. Traditionally, the most costly

aspect of carbon sequestration is separating

the CO2 from the other effluents. The pure

CO2 emission allows for easy and cost-

effective carbon sequestration from the

Bloom systems.

2) Reverse Backup: Businesses often purchase

generators, uninterruptible power supplies

and other expensive backup applications that

sit idle 99% of the time, while they purchase

their electricity from the grid as their primary

source. The Bloom solution allows customers

to flip that paradigm, by using the Energy

Server as their primary power, and only

purchasing electricity from the grid to

supplement the output when necessary.

Increased asset utilization leads to

dramatically improved ROI for Bloom

Energy's customers.

3) Time to Power: The ease of placing Bloom

Energy Servers across a broad variety of

geographies and customer segments allows

systems to be installed quickly, on demand,

without the added complexity of cumbersome

combined heat and power applications or

large space requirements of solar. These

systems' environmental footprint enables

them to be exempt from local air permitting

requirements, thus streamlining the approval

process. Fast installation simply requires a

concrete pad, a fuel source, and an internet

connection.

4) DC Power: Bloom systems natively produce

DC power, which provides an elegant

solution to efficiently power DC data centers

and/or be the plug-and-play provider for DC

charging stations for electric vehicles.

5) Hydrogen Production: Bloom's technology,

with its NASA roots, can be used to generate

electricity and hydrogen. Coupled with

intermittent renewable resources like solar or

wind, Bloom’s future systems will produce

and store hydrogen to enable a 24 hour

renewable solution and provide a distributed

hydrogen fueling infrastructure for hydrogen

powered vehicles.[4]

VII. SCOPE OF BLOOM ENERGY SERVER IN INDIA

Bloom energy server has a big scope in a country

like India, where in 2009 over 300 million citizens

had no access to electricity. Over one third of

India's rural population lacked electricity, as did 6%

of the urban population. Of those who did have

access to electricity in India, the supply was

intermittent and unreliable. In 2010, blackouts and

power shedding interrupted irrigation and

manufacturing across the country. The per capita

average annual domestic electricity consumption in

India in 2009 was 96 Wh in rural areas and 288 Wh

in urban areas for those with access to electricity.

[11][7]

No Connection45%

>100 kWh 11%

50 - 100 kWh11%

<50 kWh 33%

Fig 7. Distribution of Household Monthly Electricity Consumption

(2005). [7]

Bloom energy server can act as a boon for rural

areas where it is troublesome to provide electricity

through cables. Also it can be powered by biogas,

which can be cheaply and easily made available in

such areas. Apart from this when it comes to urban

India, it can provide electricity to shopping malls,

housing societies, corporate offices, like we have

discussed in section VI.

Table I given below gives detailed description of

how much money can be saved if Bloom Energy

Server is used. The fuel cost considered is current

(2012) charges of MGL gas supply which is

Rs. 33.10= $0.67 per kg. Also 1 MMBTU=20.22kg

of natural gas. EBay from its 5 Energy Servers had

saved about $100,000 energy costs in just 9 months.

Adobe too had saved $500,000 from its 1.2MW

Bloom Energy Servers. [1][12]

TABLE I

Cost savings of Bloom Energy Server/year (assuming full load operation)

Parameter Name Value Unit /

description

Fuel (Natural Gas) flow

rate for 200 KW Bloom

Energy Server

1.032 MMBTU/hr

Fuel energy in rate in

KW (1 MMBTU CH4 =

293 KW)

302.376 KW

Fuel cost $13.81 1.032

MMBTU/hr

Electric output rate 242 KW

Efficiency Natural Gas

-> Electricity

80% Percent

conversion of

Natural Gas

energy to

electrical

energy

Electricity cost in India $0.16 per KWh

Electricity produced

revenue

$38.72 per hour

CO2 produced 0.773 lb/kWh,

carbon

neutral on

Directed

Biogas

Run cost savings per

bloom box (electricity

revenue less fuel cost)

$24.91 Per hr

Cost savings per year

assuming 24X7 full load

operation

$218211.6 per year

Capital cost (estimated

minimum cost after

projected reductions)

$800,000.00 for each 200

KW unit

Annual maintenance /

operation cost

10% as a fraction

of capital

cost, per year

Cost savings after

maintenance costs

$138211.6 per year

Cost Savings per 1

household(considering

electricity is supplied to

300 houses)

$460.71

=

Rs.23035.27

Per year

Already, faced with crippling electricity shortages,

price of electricity traded internally, touched Rs 7

(14.3 cents) per unit for base loads and around Rs

8.50 (17.34 cents) per unit during peak periods. In

the situation of energy shortages, the country is

increasing the use of diesel-based electricity, which

is both expensive –costs as high as Rs 15 (30.6

cents) per unit, and polluting.

A Bloom box costs some $800,000 or about

$8,000 per kilowatt. However, California offers a

20% subsidy. And then there’s additional 30

percent federal government tax credit in US for

"green" investments. The payback time on a Bloom

box is thus about five years excluding the fuel

charges. A similar plan can be implemented in India

too, which will prove cost effective, more reliable

and self sufficient source of electricity.

VIII. CONCLUSION

By above analysis we conclude that Bloom

Energy Server is an eco friendly and cost effective

source of energy and thus it is a better alternative

for the already existing energy sources. The cost of

electricity over a Bloom server’s 10-year life is:

$0.08/kWh to $0.10/kWh (when running as base-

load for 24 hours a day), including 30%

government incentives and assuming a

$10/mmBTU natural gas. Without incentives, we

calculate electricity would cost $0.146/kWh to

$0.166/kWh, with about $0.1/kWh from system

cost and about $0.066/kWh coming from fuel cost.

This price is lower than average national cost of

electricity which around $0.173/kWh.

With little subsidies from government, like that

one in U.S., the prices can be reduced further. It’s

not the savings that makes this Energy Server a

better option, but it’s the eco-friendliness that does

it. Bloom Energy Server is a green source of energy

and reduces carbon emissions from 60 to

100%.When it comes to the developing countries

like India, it is a technological boon. Thus by

adopting Bloom energy Server India will bloom

with prosperity.

REFERENCES

[1] LaMonica, Martin, Parsing fact from fiction with the Bloom

Energy box, Cnet news, 2010.

[2] Mitlitsky, Fred; Sridhar, K.R.; Gottmann, Matthias; and

Venkataraman, Swaminathan,” Method for the co-production

of hydrogen and electricity in a high temperature

electrochemical system”, U.S. patent 08071246.

[3] Sridhar, K. R.; McElroy, James F.; Finn, John E.; Mitlitsky,

Fred; and Gottmann, Matthias ,” Method of optimizing

operating efficiency of fuel cells”, U.S. patent 08071241.

[4] The Bloom Energy website. Available :

http://www.bloomenergy.com

[5] Schwartz, Ariel, How Does the Bloom Box Energy Server

Work?, www.fastcompany.com, 2010.

[6] Kanellos, Michael, Bloom vs. Solar: Which One Is Best?,

http://www.wired.com/epicenter/, 2010.

[7] Residential consumption of electricity in India, Background

Paper of “India: Strategies for Low Carbon Growth”, Draft To

World Bank, July, 2008

[8] Khan, T.H., Systematic Chemistry, Uttam Prakashan, Mumbai,

First edition, 2007.

[9] A. Boudghene Stambouli, E. Traversa, Solid oxide fuel cells

(SOFCs): a review of an environmentally clean and efficient

source of energy, University of Roma ‘Tor Vergata’,

Department of Chemical Science and Technology, 2002.

[10] Pricing and Infrastructure Costing for Supply and Distribution

of CNG and ULSD to the Transport Sector in Mumbai, India, Tata Energy Research Institute, New Delhi.

[11] Narasimha Rao, Stanford University, Girish Sant, Prayas Sudhir Chella Rajan, Indian Institute of Technology Madras, for Prayas Energy Group, An overview of Indian

Energy Trends: Low Carbon Growth and Development

Challenges, Pune,2009.

[12] Mahanagar Gas Limited website. Available: www.mahanagargas.com.