mega- and gigacities and their challenges for energy and

Electricity and the Human Prospect Arnulf Grubler 2004

Mega- and Gigacitiesand their Challenges for Energy

and Electrical Systems

Arnulf GrublerIIASA and FES Yale University

Electricity and the Human ProspectStanford University December 9, 2004


Points for Discussion

• Urbanization (current + projections)• Is continued urbanization plausible? (yes)• Energy challenges of cities

(power density)• Urbanization and electricity use

(where are the lights?)• Gigacities (from city stars to city galaxies)• Implications (need for new infrastructures

and zero-emission energy = ele + H2)


Cities

~50 % of world population (~2007)

>80? % of world GDP (few data)

>80? % of world electricty (no data)

~95 % of world internet sites and traffic(good data)


Urbanization• Pre-1700: Limited by agricultural

surplus production: <10% urban• Size limit: Size of empire reach and

availability of transport infrastructureFirst „Megacity“: Changan, China 800 AD (canals)

• Post 1700: Urbanization enabled byagricultural productivity growth, division of labor, new transport infrastructures (railways)

• ~2000: Mid-point. 50% urban globally• Asymptotic state: >90% by >2100?


-2

-1

0

1

2

900 1100 1300 1500 1700 1900 2100 2300 2500

log

(urb

an/n

on-u

rban

)

50%

10%

99%

90%

Percent urban

Δt = 315 yrs

Data:pre-1950: own estimates; 1950-2030: UN, 2002.

1%

World Urbanization


Population Density1990 and Two Scenarios for 2070


Does Space Matter?:“[the] report of my death was an exaggeration” (Mark Twain)

NY Internet Domains Source: Zook, 2001


Energy and Electricity Challenges of Cities

• Spatial mismatch demand – supply(vast imports)

• Enormous power densities(limiting supply options)

• Vulnerability requires extreme reliability• Congestion needs high tech solutions• Assimilative capacity of environment

extremely limited (need for zero emissions)


Spatial Power Densities ofEnergy Production and Consumption

Megacities


Tokyo Electricity Demandand Solar Supply Potential


Let there be Light…

• Indicator of vulnerability (black-outs)• Show potential demand

(combined with socio-economic data)• Formal modeling (high correlation with

GDP and electricity use)• Simulating (spatially explicit) futures


2000

Night Luminosity Map

Source: Adapted from NOAA

Electricity and the Human Prospect Arnulf Grubler 2004Population Density

Electricity and the Human Prospect Arnulf Grubler 2004Electricity UseElectricty Use


Population and Electricity Use


Nighttime Lights vs. Electricity Usefor 135 countries by region in 1996

y = 0.9017x - 0.8232R2 = 0.8584

3

4

5

6

7

8

9

5 6 7 8 9 10

NAMPAOWEUEEUFSUAFRLAMMEACPAPASSAS

log electricity use (MWhr)

log

nigh

time

light

s (s

um o

f dim

ensi

onle

ss in

dica

tors

)


Electrification Scenarios(using GDP as proxy indicator)


From Mega- to Gigacities

• Hierarchies in city size: rank-size (RS, Zipf)• Stability of RS since 1000 AD• Pre-1700: Max. city size: <1 Million

(few stars, most in Asia)• Post-1700: Max size: <10 Million

(many stars, most in Europe+”offshoots”)• Post 1900: Emergence of city clusters <100

Million (urban galaxies, dominance of Asia)• Possible discontinuity in 2070 (demographics

of declining population, Europe & China)


0

5

10

15

20

1 2 3 4 5900 1250 1500 1700 1800 6 71900 2000

200

50

100

150

Asia

Africa

Europe

European off-shoots

10 Largest Cities AD 900-2000

900-1800 1900-2000

Data: T. Chandler, 1987; UN, 2003.


World Cities:Ranke Size Distribution 900 to 2000 AD

-2

-1

0

1

2

-1 0 1 2 3Rank

Popu

latio

n (M

illion

)

1 10 100 1000

1

10

100

.1

.01

Chinese Sea

900

125015001700

1800

-2

-1

0

1

2

-1 0 1 2 3Rank

Popu

latio

n (M

illion

)

1 10 100 1000

1

10

100

.1

.01

Chinese Sea

900

125015001700

1800

……..…

2000 with city clusters

1900

19502000


World Cities 900-2000 AD

-2

-1

0

1

2

-1 0 1 2 3Rank

Pop

ulat

ion

(Mill

ion)

1 10 100 1000

1

10

100

.1

.01

BagdadPeking

Peking

Hangchow

London

Tokyo

Chinese Sea SHIN

KANS

ENSA

O-RIO

GREA

T LA

KES

BOSW

ASH

CALI

FORN

IA

MEX

ICO-C

ENTR

O

GANGA

MUM

POONE

RHIN

E-RUH

R

JAVA

BENGAL D

ELTA

New York

Chinese Seacoast?

..............

mega- and gigacities and their challenges for energy and

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