Energy and the New Reality, Volume 2:

C-Free Energy Supply

Chapter 10: The Hydrogen Economy

L. D. Danny Harveyharvey@geog.utoronto.ca

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Publisher: Earthscan, UKHomepage: www.earthscan.co.uk/?tabid=101808

Figure 10.1 Efficiency of steam methane reforming to produce hydrogen

S = 2

S = 3

S = 4

Theoretical

80

60

40

20

0500 600 700 800 900 1000

Reforming T ( C)o

Source: Lutz et al (2003, International Journal of Hydrogen Energy 28, 159–167, http://www.sciencedirect.com/science/journal/03603199)

Figure 10.2 Capital cost of steam methane reformers

Source: Modified from Weinert and Lipman (2006, An Assessment of Near-Term Costs of Hydrogen Refueling Stations and Station Components, Institute of Transportation Studies, UC Davis)

0

200

400

600

800

1000

1200

0 5 10 15 20 25

Co

st

(10

00

$)

Capacity (kg/hr)

Industry

Literature

$1500/kW

$1500/kW

$3000/kW$6000/kW

Figure 10.3 Capital cost of electrolyzers

Source: Modified from Weinert and Lipman (2006, An Assessment of Near-Term Costs of Hydrogen Refueling Stations and Station Components, Institute of Transportation Studies, UC Davis)

0

200

400

600

800

1000

0 2 4 6 8 10

Co

st

(10

00

$)

Capacity (kg/hr)

Industry

Literature

$1500/kW

$3000/kW

$6000/kW

Figure 10.4 Contributions to the total electrolysis voltage as a function of current density

0.0

0.3

0.5

0.8

1.0

1.3

1.5

1.8

2.0

0 1 2 3 4 5 6 7 8 9 10

Ele

ctro

lysi

s Vo

ltag

e, V

Current Density (kA/m2)

Theoretical Minimum Voltage for Water Electrolysis

Electrolyte Resistance

Anode activation

Cathode activation"Thermo-neutral" electrolysis voltage (1.48 V)

Source: Berry et al (2003a, Encyclopedia of Energy, Elsevier 3, 253-265, http://www.sciencedirect.com/science/referenceworks/9780121764807)

Figure 10.5 Typical variation of electrolysis efficiency with load

70

75

80

85

90

95

100

0 20 40 60 80 100 120

Eff

icie

ncy

(%

)

Load (as a percentage of nominal power input)

Source: Ntziachristos et al (2005, Renewable Energy 30, 1471–1487, http://www.sciencedirect.com/science/journal/09601481)

Figure 10.6 Variation with operating temperature of the energy inputs required for electrolysis

0

50

100

150

200

250

300

200 400 600 800 1000

En

erg

y In

pu

t (k

J/m

ol

H2)

Temperature (oC)

Electrical energy input

Thermal energy input

Total energy input

Source: Ni et al (2007, International Journal of Hydrogen Energy 32, 4648–4660, http://www.sciencedirect.com/science/journal/03603199)

Figure 10.7 Solar H2 production through high-temperature electrolysis

ThermalEngine

100 units

Heat

50 units

SolarThermal

Collectors

Waste Heat

Electricity Electro-lyzer

H O2

O2

H , 24 units2

Heat H , = 0.472

= 0.50

Figure 10.8 PEC Structure

Source: Bak et al (2003, International Journal of Hydrogen Energy 27, 991-1022, http://www.sciencedirect.com/science/journal/03603199)

Figure 10.9 Energy required to compress hydrogen

0

2

4

6

8

10

12

0

4

8

12

16

20

24

0 200 400 600 800 1000

Ra

tio

of

H2:C

H4

Co

mp

res

sio

na

l E

ne

rgie

s

Co

mp

res

sio

na

l En

erg

y (%

of

H2

LH

V))

Final Pressure (atm)

Series7Series5Series6AdiabaticActualIsothermal

Compressional Energy

Adiabatic H2:CH4

Figure 10.10 Energy required to transmit natural gas and H2 by pipeline

0

10

20

30

40

50

60

70

0 1000 2000 3000 4000 5000

Distance (km)

Tra

ns

it E

ner

gy

/Del

iver

ed E

ne

rgy

(%)

Hydrogen, same D as for methane

Hydrogen, same V as for methane

Methane

Figure 10.11 Cost of transmitting various a mixture consisting of various proportions of natural gas and hydrogen,

as a function of pipe diameter

0

1

2

3

4

0.1 0.3 0.5 0.7 0.9 1.1 1.3 1.5Pipe D iam eter (m )

Tra

nsm

issi

on

Co

st($

/GJ)

Series7

0.0

0.20.40.6

0.8

1.0

H F rac tion2

Source: Oney et al (1994 , International Journal of Hydrogen Energy 19, 813–822, http://www.sciencedirect.com/science/journal/03603199)

Figure 10.12a Hydrogen Aircraft

-20

-10

0

10

20

30

40

50

60

Business Jet

Small Regional Aircraft

Regional Propeller Aircraft

Regional Jet

Aircraft

Medium-Range Aircraft

Long-Range Aircraft

Very-Long-Range Aircraft

Pe

rce

nt

Ch

an

ge

in

We

igh

tOperating Empty Weight

Maximum Take-Off Weight

Source: Airbus (2003, Liquid Hydrogen Fuelled Aircraft – System Analysis. Final Technical Report (Publishable Version), Airbus Deutschland GmbH (Project Coordinator) Project No GRd1-1999-10014, www.aero-net.org)

Figure 10.12b Hydrogen Aircraft

0

10

20

30

40

Business Jet

Small Regional Aircraft

Regional Propeller Aircraft

Regional Jet

Aircraft

Medium-Range Aircraft

Long-Range Aircraft

Very-Long-Range Aircraft

Pe

rce

nt

Ch

an

ge

in

Fu

el

Co

ns

um

pti

on

Source: Airbus (2003, Liquid Hydrogen Fuelled Aircraft – System Analysis. Final Technical Report (Publishable Version), Airbus Deutschland GmbH (Project Coordinator) Project No GRd1-1999-10014, www.aero-net.org)

Figure 10.13 Cost of H2 produced by steam reforming of natural gas or by electrolysis of water

0

5

10

15

20

25

30

35

40

0 2 4 6 8

Co

st

of

Hyd

rog

en

($

/GJ

)

Cost of Electricity (cents/kWh)

Electrolysis of Water, CF=0.25CF=0.9

Steam Reformingof Natural Gas

0 4 8 12 16

Cost of Natural Gas ($/GJ)

Figure 10.14 Cost of gas transmission vs. energy flow rate

0.0

0.5

1.0

1.5

2.0

2.5

3.0

0 200 400 600

Energy Flow Rate (1000s GJ/day)

Co

st o

f T

ran

smis

sio

n (

$/G

J)

Natural Gas

Hydrogen

Source: Ogden, J. M. (1999, Annual Review of Energy and the Environment 24, pp227–279)

Figure 10.15 Cost of H2 that just offsets (through reduced fuel costs) the increased purchase cost of H2-powered vehicle over a

10-year operating life for gasoline at $1.0/itre to $2.0/litre

2

12

22

32

42

52

62

0

5

10

15

20

25

1000 2000 3000 4000 5000

All

ow

ed

Hyd

rog

en

Co

st

($/G

J)

All

ow

ed

Hyd

rog

en

Co

st

(ce

nts

/kW

h)

Upfront Cost Premium ($)

$1.0/litre

$1.5/litre

$2.0/litre

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