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.

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.

 

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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