Energy and the New Reality, Volume 1:
Energy Efficiency and the
Demand for Energy Services
Chapter 2: Energy Basics
L. D. Danny Harvey
harvey@geog.utoronto.ca
Publisher: Earthscan, UK
Homepage: www.earthscan.co.uk/?tabid=101807
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Forms of energy
• Primary energy – as it is found in nature
(coal, oil, natural gas in the ground)
• Secondary energy – energy that has
been converted from primary energy to
another form (electricity, refined petroleum
products, processed natural gas)
• Tertiary energy – one more step in the
chain – end-use energy (what we actually
want: light, heat, cooling and mechanical
power)
Conversions:
• Secondary energy =
primary energy x conversion efficiency
• So, given an amount of secondary energy,
divide by the conversion efficiency to get
the amount of primary energy required to
produce that amount of secondary energy
Figure 2.1 Primary to Secondary to End-Use Energy
Losses
P rim a ry
E n e rg y
Tra n s fo rm a tio n
Tra n s p o rta tio n
D is trib u tio n
Losses
S e c o n d a ry
E n e rg y
U tiliz a tio n
F in a l
D e v ic e o r
U s e fu l
S y s te m
E n e rg y
Primary Energy Equivalent of Electricity
from Hydropower or Nuclear Power:
• Electricity from hydro and nuclear could instead be
produced by burning fossil fuels to generate
electricity
• So, divide the amount of hydro or nuclear electricity
by the efficiency in generating electricity from fossil
fuels to get the primary energy equivalent of the
hydro or nuclear electricity
• I use a standardized efficiency of 40%
• Thus, 1 MJ of hydro or nuclear (or wind or solar)
electricity is treated here as the equivalent of 2.5 MJ
of primary energy
Energy and Power
• Energy (the ability to do work) has units of joules
(J)
• Power is the rate of supplying energy, and has
units of watts (W), where 1 W = 1 J/s
• Thus, to convert power to energy used, we
multiply by the length of time in seconds over
which the power is supplied, whereas to convert
the amount of energy used over a given time to
the average power, we divide energy by time in
seconds
Big Numbers
• It is convenient to represent global and regional
annual energy use in units of exajoules, where 1
EJ = 1018 joules, and to represent world power
demand in gigawatts or terawatts, where 1 GW
= 109 watts and 1 TW = 1012 watts,
so 1 TW=1000 GW
• Primary power (W) demand is given by annual
energy use (J) divided by the number of
seconds in one year
• Thus, total world primary energy use in 2005 of
483 EJ corresponds to an average rate of supply
of primary energy (primary power) of 15.3 TW
Electrical Energy
• When it comes to the energy supplied by an
electrical power plant, it is common to multiply the
power times the number of hours in the time period
during which the power is supplied
• Thus,
from kW (kilowatts) we get kWh (kilowatt-hours)
from GW (gigwatts) we get GWh (gigawatt-hours)
from TW (terawatts) we get TWh (terawatt-hours)
• To convert energy in units of kWh, GWh or TWh into
energy in units involving joules, multiply by the
number of seconds in an hour (and divide by the
appropriate factor of 10, depending on the desired
final units)
Figure 2.2a Growth in the Use of Primary Energy
500
Primary Energy Use (EJ/year)
450
400
350
Asia Pacific
Africa
Middle East
FSU
Europe
S & C America
N America
+636%, 4.9%/yr
300
+462%, 4.2%/yr
+887%, 5.6%/yr
250
200
+68%, 1.3%/yr
150
+91%, 1.6%/yr
+385%, 3.9%/yr
100
50
+101%, 1.7%/yr
0
1965 1970 1975 1980 1985 1990 1995 2000 2005
Year
Figure 2.2b Growth in the use of primary energy
600
Primary Energy Use (EJ/year)
500
Hydro +227%, 2.9%/yr
400
Nuclear +79%, 2.8%/yr (1985-2006)
300
Coal +109%, 1.8%/yr
200
100
Natural Gas +335%, 3.6%/yr
Oil +168%, 2.4%/year
0
1965 1970 1975 1980 1985 1990 1995 2000 2005
Year
Figure 2.3 Variation in the price of crude oil, 1860-2008
Price of Crude Oil (US$/barrel)
100
90
80
In money of the day
In 2008 US$
70
60
50
40
30
20
10
0
1860
1910
1960
Year
2010
Figure 2.4 Price of Oil, Natural Gas and Coal
18
Energy Price (US 2008$/GJ)
16
14
12
10
Crude Oil
LNG in Japan
NG in EU
US Henry Hub NG
Alberta NG
Japan, Imported Coal
NW European coal
US Appalachian Coal
8
6
4
2
0
1988
1993
1998
Year
2003
2008
Figure 2.5a Growth in Electricity Supply
Electricity Generation (TWh/yr)
20000
18000
16000
14000
12000
Asia Pacific
Africa
Middle East
FSU
Europe
C & S America
North America
6.1%/yr
4.0%/yr
10000
6.6%/yr
-1.1%/yr
8000
1.8%/yr
6000
4.3%/yr
4000
1.8%/yr
2000
0
1990
1994
1998
Year
2002
2006
Figure 2.5b Growth in Electricity Supply
by Energy Source
Electricity Generation (TWh/yr)
20000
18000
Overall Increase in Electricity Use,
1990-2006: +60%, 3.0%/yr
16000
1.8%/yr
14000
2.1%/yr
12000
10000
8000
6000
4000
Nuclear
Hydro
Fossil
3.4%/yr
2000
0
1990
1994
1998
Year
2002
2006
Overview of Energy Supply and Use
in 2005
Figure 2.6a World Primary Energy Sources in 2005
Biomass
9.9%
Other
0.5%
Coal
25.0%
Hydro
5.9%
Nuclear
5.1%
Natural Gas
20.5%
Oil
33.2%
Total = 483.3 EJ
Figure 2.6b OECD Primary Energy Sources in 2005
Biomass 3.5%
Other
0.7%
Coal
20.2%
Hydro 4.7%
Nuclear 8.7%
Natural Gas
21.9%
Oil
40.3%
Total = 231.9 EJ
Figure 2.6c Non-OECD Primary Energy Sources in 2005
Biomass
15.9%
Other
0.3%
Coal
29.4%
Hydro
6.9%
Nuclear
1.8%
Natural Gas
19.2%
Oil
26.5%
Total = 251.4 EJ
Figure 2.7a Uses of Coal in 2005
District Heat
3.3%
Own Use
1.1% Non-energy &
Other
0.3%
Buildings
1.4%
Industry
14.9%
Own Use
3.9%
Non-energy &
Other 3.1%
District Heat
6.8%
Buildings
4.0%
Electricity
Generation
52.5%
Industry
29.6%
Electricity
Generation
79.0%
OECD Countries
non-OECD Countries
Figure 2.7b Uses of Oil in 2005
Non-energy
15.6%
Electricity
Other Generation
2.2%
4.9%
Other
5.4%
Non-energy
12.2%
Electricity
Generation
10.2%
Own Use
6.3%
Own Use
5.4%
District Heat
1.2%
District Heat
0.5%
Buildings
8.9%
Buildings
9.8%
Industry
6.2%
Transportation
Transportation
56.3%
OECD Countries
Industry
14.9%
39.9%
non-OECD Countries
Figure 2.7c Uses of Natural Gas in 2005
Non-energy
3.0%
Own Use
9.3%
Other
0.9%
District Heat
4.5%
Electricity
Generation
26.8%
Transportation
0.1%
Buildings
34.4%
Industry
21.1%
OECD Countries
Non-energy
8.3%
Other
2.0%
Own Use
15.4%
Electricity
Generation
30.8%
Transportation
0.6%
District Heat
14.4%
Buildings
12.9%
Industry
15.6%
non-OECD Countries
Figure 2.8 Direct Primary Energy Use in 2005
Non-specified 0.2%
Non-energy use
7.4%
Non-energy use
6.3%
Residential
Buildings 9.2%
Non-specified
1.6%
Commercial
Buildings 4.6%
Electricity
Generation
38.5%
Agriculture
1.2%
Electricity
Generation
33.2%
Residential
Buildings
19.1%
Commercial
Buildings
1.6%
Transportation
24.2%
District Heating
2.1%
Industry
12.5%
OECD Countries, Total = 231.9 EJ
Agriculture
1.6%
Transportation
12.3%
District Heating
5.2%
Industry
19.3%
non-OECD Countries, Total = 251.4 EJ
Figure 2.9 Electricity Use By Sector in 2005
Agriculture
0.8%
Transport
1.1%
Other
1.5%
Power Plant
5.5%
Distribution
6.5%
Commercial
25.2%
Industry
32.2%
Residential
27.3%
OECD Countries, Total = 10392 TWh
Other
3.9%
Power Plant
Agriculture
6.2%
3.9%
Transport
Distribution
1.8%
11.8%
Commercial
10.8%
Residential
17.8%
Industry
43.9%
non-OECD Countries, Total = 7841 TWh
Figure 2.10 Primary Energy Use by Sector in 2005 (after
allocation of energy used to generate electricity to the
sectors that use the electricity)
Non-energy
7.5%
Agriculture
1.5%
Agriculture
3.4%
Other
1.8%
Industry
26.2%
Other
3.3%
Non-energy
6.4%
Commercial
6.7%
Commercial
16.1%
Industry
37.8%
Residential
28.3%
Residential
21.8%
Transport
25.0%
OECD Countries, Total = 231.9 EJ
Transport
14.1%
non-OECD Countries, Total = 251.4 EJ
Figure 2.11 Annual Electricity Use per capita in 2005
20000
18000
16000
12000
10000
8000
6000
4000
2000
di
a
In
na
hi
C
R
us
si
a
y
m
an
G
er
n
Ja
pa
e
an
c
Fr
ia
tr
al
A
us
U
S
an
a
da
0
C
kWh/yr/person
14000
Figure 2.12 Distribution of Global
Electricity Generating Capacity in 2005
Nuclear
8.9%
Wind
1.4%
Geothermal
1.5%
Hydro
20.3%
Thermal
67.8%
Total = 4267 GW
Figure 2.13 Distribution of Global Electricity
Generated by Source in 2005 (IEA data)
Wind+Solar
0.7%
Geothermal
Biomass+Waste
0.3%
1.2%
Hydro
16.0%
Coal
40.3%
Nuclear
15.2%
Natural Gas
19.7%
Oil
6.5%
Total = 18223 TWh
Figure 2.14 Geographical Distribution of Electricity
Generating Capacity in 2005
Africa
2.6%
Oceania
1.5%
South America
4.5%
Asia
34.1%
Europe
27.4%
North America
30.0%
Total = 4267 GW
Energy Resource and Energy Reserves
• Energy Resource: in the case of non-renewable
energy: how much is there in the ground and
potentially extractable
• Energy Reserve: that portion of the resources
that it is worthwhile extracting given current
prices and technology
• As technology improves or prices increase, some
of the energy in the resource base becomes part
of the reserve
Figure 2.15 Hypothetical increase in the cost of natural
gas in the US with increasing cumulative extraction
US$'(88) per barrel of oil equivalent
50
40
No technology
advances
30
20
With technology
advances
10
0
2
4
6
8
10
12
14
16
18
Gigatonnes of oil equivalent
Source: Rogner (1997, Annual Review of Energy and the Environment 22, 217–262)