Introduction
History of the Energy System
Human Energy Needs
Science Notes
Energy Transformation
Measuring Matter, Force, & Energy
Energy Accounting & Balance
Fundamental Forces of Nature
Energy and Chemical Stability
Chemical Formations
Chemistry of Fossil Fuels
Energy Use, Efficiency, and the Future
Energy Sources, Technologies, & Impacts
Exercises
Internet Links
Other Resources
Energy System PDF
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Human Energy Needs

Figure 5: Composite of satellite images showing the extent of outdoor lighting
in the continental United States. Image and data processing by NOAA's National Geophysical Data Center. Defense Meteorological Satellite Program (DMSP) data collected by US Air Force Weather Agency.

Our energy consumption has led us to develop new energy sources and technologies. In a century, liquid fuels and electricity have improved our standard of living and provided us with more mobility than people in any other era. This section reviews our human energy needs, how we currently meet them, and what the future may have to offer.

Energy is essential for all we do as individuals and as societies. Energy production, use, and distribution also cause some of the most pressing environmental problems. Figure 6 shows the overall picture of human energy needs, the ways in which we meet our energy needs, and the impacts.

Figure 6: Flowchart of Energy Needs.

Although industrialized countries use the most energy at present, newly industrialized countries are increasing their rate of use. Figure 7 graphs the projected energy needs of industrialized countries, developing countries, and Eastern Europe and the former Soviet Union. Many environmental and economic issues arise from the escalating energy use all over the world. Understanding the science and technology driving the energy system enables us to better understand our relationship to the environment.

Energy Use and Sources - Data
Figure 7: Projected Energy Needs.
Source: DOE/EIA


The daily energy needs -- especially of industrialized countries -- are vast. The United States used 3,236 billion kilowatt-hours (kWh) in 1999 for a population of approximately 300 million. This is more than a million kWh per person per year! (This includes all sectors of energy used.) Table 2 gives the billions of kilowatt-hours of electricity used by various regions.

Region

History

Projections

1990

1999

2005

2010

2015

2020

Average Annual Percent Change, 1999-2020

Industrialized Countries

6,385

7,517

8,580

9,352

10,112

10,888

1.8

  United States

2,817

3,236

3,761

4,147

4,484

4,804

1.9

EE/FSU

1,906

1,452

1,622

1,760

1,972

2,138

1.9

Developing Countries

2,258

3,863

4,988

6,191

7,615

9,203

4.2

  Developing Asia

1,259

2,319

3,088

3,883

4,815

5,856

4.5

    China

551

1,084

1,533

2,035

2,635

3,331

5.5

    India

257

424

545

656

798

949

3.9

    South Korea

93

233

294

333

386

437

3.0

    Other Developing Asia

357

578

716

858

996

1,139

3.3

  Central and South America

449

684

844

1,035

1,268

1,552

4.0

Total World

10,549

12,833

15,190

17,303

19,699

22,230

2.7

Note: EE/FSU = Eastern Europe and the former Soviet Union.
Sources: History: Energy Information Administration (EIA), International Energy Annual 1999, DOE/EIA-0219(99) (Washington, DC, January 2001). Projections: EIA, World Energy Projection System (2001).

Table 2: World Net Electricity Consumption by Region, 1990-2020
(Billion Kilowatt-hours)
Source: DOE/EIA

The factors that affect energy use most are the level of industrialization, the climate of the region, and the population. These factors are not independent of each other. All of these factors influence energy choices, production, distribution, and usage. The average use of energy per person in different countries varies widely. Table 3 highlights world energy consumption for electricity generation by region and fuel source. It is evident in these tables that industrialized countries use more energy.

Region and Fuel

History

Projections

1995

1999

2005

2010

2015

2020

Industrialized

77.1

83.8

91.6

97.2

103.5

108.0

  Oil

5.7

6.5

5.4

5.3

5.5

5.9

  Natural Gas

9.7

11.6

15.6

18.3

23.1

27.4

  Coal

27.7

29.5

32.1

33.4

34.0

34.3

  Nuclear

19.4

20.6

20.9

20.9

20.5

19.1

  Renewables

14.7

15.6

17.5

19.4

20.4

21.3

EE/FSU

26.4

23.8

25.9

27.0

28.9

30.8

  Oil

2.8

2.4

3.1

3.5

4.2

4.7

  Natural Gas

10.6

10.3

11.1

12.3

14.4

15.9

  Coal

7.4

5.4

5.4

4.5

3.3

2.8

  Nuclear

2.5

2.7

3.2

3.1

3.1

2.8

  Renewables

3.1

3.0

3.2

3.5

4.0

4.5

Developing

38.1

40.9

52.3

63.1

75.0

86.6

  Oil

5.1

5.7

6.9

8.3

10.0

12.0

  Natural Gas

4.8

6.0

8.4

11.0

13.6

16.4

  Coal

16.8

15.8

20.4

24.7

29.2

32.6

  Nuclear

1.4

1.9

2.6

3.4

4.1

5.1

  Renewables

10.1

11.5

14.1

15.8

18.2

20.5

Total World

141.7

148.4

169.8

187.3

207.4

225.4

  Oil

13.6

14.6

15.4

17.0

19.7

22.5

  Natural Gas

25.1

27.9

35.2

41.7

51.0

59.7

  Coal

51.9

50.7

57.8

62.5

66.5

69.7

  Nuclear

23.3

25.3

26.7

27.4

27.7

27.1

  Renewables

27.9

30.0

34.8

38.7

42.5

46.4

Note: EE/FSU = Eastern Europe and the former Soviet Union.
Sources: History: Derived from Energy Information Administration (EIA), International Energy Annual 1999, DOE/EIA-0219(99) (Washington, DC, January 2001). Projections: EIA, World Energy Projection System (2001).

Table 3: World Energy Consumption for Electricity Generation by Region and Fuel, 1995-2020
(Quadrillion Btu)
Source: DOE/EIA

 

Information describing our energy use often can be evasive. Figure 8 shows the main heating fuels the U.S. uses for residential home heating. Electricity use for heating is on the rise; however, electricity is not a direct fuel source like the others in this figure. It is a form of energy. Different sources, such as coal and uranium, are used to generate electricity. Therefore, if electricity use is on the rise, the use of coal and uranium are also on the rise.

Figure 8: Main Heating Fuels.
Source: DOE/EIA

We are all affected by and pay for the life cycle of electricity. As end users of electricity, understanding the process of electricity generation gives a clearer picture of what you are paying for and helps in your decision making as a consumer.

Transportation as an Energy Sector
Liquid fuels such as gasoline have made our lives more mobile. Desire to maintain our current ability to travel and the fact that crude oil is a non-renewable energy source, have encouraged the development of new technologies are being developed. Meanwhile, our current travel habits are fast depleting the crude oil stores on Earth.

Energy use for transportation is the least efficient use of fossil fuels. The automobile loses far more energy than it uses. As shown later (in the Energy Transformation section), for every 20 gallons put into a car we only get about 2 gallons worth of actual work. The rest is dissipated as heat. The other inherent inefficiency is in the fact that to move one person, we have to spend energy moving over a ton of extra material (the automobile itself).

Figure 9: Average Annual Residential Vehicle Fuel Consumption by Region, 1994.
Source: DOE/EIA

Use of crude oil is escalating as developing countries emulate industrialized mobility. Figure 8 graphs the use of crude oil for transportation needs. This increase in oil consumption specifically for transportation not only impacts the environment, it will deplete the limited oil reserves in the earth's core. Increased consumption of oil for transportation could also affect a variety of industries (i.e. plastics) which in turn affects the economy.

Figure 10: Use of Crude Oil for Transportation Needs.
Source: DOE/EIA

A review of the science supporting our current energy systems can be found in the section "Science Notes."

 

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  ©Copyright 2003 Carnegie Mellon University
This material is based upon work supported by the National Science Foundation under Grant Number 9653194. Any opinions, findings, and conclusions or recommendations expressed in this material are those of the authors and do not necessarily reflect the views of the National Science Foundation.