Renewable Energy - A Historical Perspective

Before the nineteenth century most energy used came from renewable sources. People burned wood for heat, used sails to harness the wind and propel boats, and installed water wheels on streams to grind grain. The large-scale shift to nonrenewable energy sources began in the 1800s with the Industrial Revolution, a period marked by the rise of factories—first in Europe and then in North America. Coal was the most efficient fuel for the steam engine, which was perhaps the most important invention of the Industrial Revolution. By the turn of the twentieth century, coal had replaced wood as the main fuel source.

Coal's dominance, however, lasted only a few decades. In the early 1950s petroleum products such as gasoline and diesel fuel surpassed coal as the fuel of choice. (See Figure 10.1.) Until the early 1970s most Americans were unconcerned about the sources of the nation's energy. Supplies of coal and oil, which together provided more than 90 percent of U.S. energy, were believed to be plentiful. The decades preceding the 1970s were characterized by cheap gasoline and little public discussion of energy conservation.

That carefree approach to energy consumption ended in the 1970s. A fuel oil crisis brought on by political events in the Middle East made Americans more aware of the importance of developing alternative sources of energy to supplement and perhaps even replace fossil fuels. In major cities throughout the United States, gasoline rationing became commonplace, lower thermostat settings for offices and living quarters were encouraged, and people waited in line to fill their gas tanks. The crisis was over by the late 1970s and oil prices dropped, but the incident shocked America, where mobility and personal transportation are highly valued. As a result, President Jimmy Carter's administration encouraged federal funding for research into alternative energy sources.

In 1978 the U.S. Congress passed the Public Utilities Regulatory Policies Act (PURPA; PL 95-617), which was designed to help the struggling alternative energy industry. The act exempted small producers from state and federal utility regulations and required existing local utilities to buy electricity from the smaller producers. PURPA encouraged the growth of small-scale electric power plants, especially those fueled by renewable sources. The renewable industries responded by growing rapidly, gaining experience, improving technologies, and lowering costs. This act was a major factor in the development of the commercial renewable energy market.

FIGURE 10.1
Energy production by major source, 1949–2002

In the 1980s President Ronald Reagan decided that private-sector financing for the short-term development of alternative energy sources was best. As a result, he proposed the reduction or elimination of federal expenditures for alternative energy sources. Although funds were severely cut, the U.S. Department of Energy (DOE) continues to support some research and development to explore alternate sources of energy. Table 10.1 shows a detailed breakdown of the nation's energy sources between 1949 and 2002. Renewable energy comprised 9 percent of the total in 1949.

How Much of Today's Energy Is Renewable?

In 2003 renewable energy accounted for only 6 percent of total U.S. energy consumption. (See Figure 10.2.) Of that hydroelectric power accounted for 44 percent, followed by wood (34 percent) and waste (10 percent). Geothermal energy sources, alcohol fuels, and wind and solar power were minor sources. (See Figure 10.3.)

Figure 10.4 shows the historical contributions of hydroelectric power, wood, and waste to renewable energy FIGURE 10.2
Renewable energy consumption as share of total energy consumption, 2003 resources since 1973. Consumption of hydroelectric and wood power has varied up and down over time, while waste shows a gradual upward trend.

Electric utility companies have historically been the biggest consumers of renewable energy because they use it to generate electricity. In 2003 electric power generation accounted for 59 percent of renewable energy consumption. It was followed by industrial uses with 30 percent of the total. Consumption by residential, commercial, and transportation sectors was minor. Industrial use has outpaced residential use since the late 1950s.