Energy Efficiency

Energy Efficiency

History of energy concerns

Energy efficiency in buildings

Transportation

Energy efficiency in industry

Other techniques for increasing energy efficiency

Government policies and regulations

Green Market electric utilities

Results and the future

Resources

Energy efficiency refers to the use of energy with less waste. For example, some automobiles (such as the hybrid Honda Insight) can travel 70 mi (112 km) by burning a single gallon of gasoline, while others, carrying the same amount of passengers and cargo, can travel only 20 miles. The energy efficiency achieved by the first car is over three times that achieved by the second car because it achieves the same end use using one third the energy. In general, energy efficiency is compared using units such as mpg, lumens per watt, or some similar “output per input” unit.

History of energy concerns

Interest in energy efficiency is relatively new in the history of modern societies, although England’s eighteenth century search for coal was prompted by the decline of the country’s forest resources. For most of the twentieth century, however, energy resources seemed to be infinite, for all practical purposes. Little concern was expressed—except, starting in the 1960s, by the concerned individuals, often scientists, dubbed “environmentalists”—about the danger of exhausting the world’s supplies of coal, oil, and natural gas, its major energy resources.

The turning point in that attitude came in the 1970s, when the major oil-producing nations of the world suddenly placed severe limits on the amounts of petroleum that they shipped to the rest of the world. This oil embargo forced major oil users such as the United States, Japan, and the nations of Western Europe to face for the first time the danger of having insufficient petroleum products to meet their basic energy needs. Use of energy resources suddenly became a matter of national and international discussion.

Energy efficiency can be accomplished in a number of different ways. One of the most obvious is conservation ; that is, simply using energy resources more carefully so as to throw less energy away. For example, people might be encouraged to turn out lights in rooms when they are not in the room, to not run hot water down the drain, to combine errands rather than making numerous separate trips. In these examples, people pay a little more attention to how they use the devices they already have. The light bulbs, water systems, and automobiles involved do not become more efficient in themselves, but they are used more efficiently. Energy efficiency also means more complex and sophisticated approaches to the way in which energy is used in industrial, commercial, and residential settings.

Energy efficiency in buildings

Approximately one-third of all the energy used in the United States goes to heat, cool, and light buildings. A number of technologies have been developed that improve the efficiency with which energy is used in buildings. Some of these changes are simple; higher grades of insulation are used in construction, and air leaks are plugged. Both of these changes reduce the amount of heated or air-conditioned air (depending on the season) lost from the building to the outside environment.

Other improvements involve the development of more efficient appliances and construction products. For example, the typical gas furnace in use in residential and commercial buildings in the 1970s was about 63% efficient. Today, gas furnaces with efficiencies of 97% are readily available and affordable. Double-glazed windows with improved insulating properties have also been developed. Such windows can save more than 10% of the energy lost by a building in a year.

Buildings can also be designed to save energy. For example, they can be oriented on a lot to take advantage of solar heating or cooling. Many commercial structures also have computerized systems that automatically adjust heating and cooling schedules to provide a comfortable environment for occupants only when and in portions of the building that are occupied.

Entirely new technologies can be used also. For example, many buildings now depend exclusively on more efficient fluorescent lighting systems than on less efficient incandescent lights. In some situations, this single change can produce a greater savings in energy use than any other modification. The increasing use of solar cells is another example of a new kind of technology that has the potential for making room and water heating much more efficient.

Transportation

About one third of the energy used in the United States goes to transportation—moving people and goods from place to place. For more than two decades, governments have made efforts (more and less serious) to convince people that they should use more energy-efficient means of transportation, such as bicycles, carpooling, or mass transit (buses, trolleys, subways, light-rail systems, etc.). These efforts have had only limited success—not simply because people are lazy, but because the settlement patterns of our society discourage many such measures. Federal government devotes many times more money to building and maintaining interstate highways than to funding bicycle lanes, mass transit, and the like.

Another approach that has been more successful has been to encourage car manufacturers to increase the efficiency of automobile engines. In the 1970s, the average fuel efficiency of cars in the United States was 13 mpg (5.5 km/l). Over the next decade, efficiency improved nearly twice over to 25 mpg (10.6 km/l). In other nations, similar improvements were made. Cars in Japan, for example, increased from an average efficiency of 23 mpg (9.8 km/l) in 1973 to 30 mpg (12.8 km/l) in 1985.

Yet, even more efficient automotive engines appear to be possible. Efficiencies exceeding 50 mpg (21 km/l) have been commercially available since about 2000, when hybrid cars such as the Honda Insight and Toyota Prius hit the U.S. market. The Prius gets about 50 mpg and the Insight about 70: both produce about a tenth as much air pollution as equivalent-sized conventional cars, and run on the same gasoline as other cars. Yet in the 1990s and early 2000s, the dominant U.S. automobile market trend was toward huge, gas-guzzling sport utility vehicles (SUVs). The efficiency of the U.S. fleet actually declined, and—despite many consumers’ belief that they are safer in an SUV—without any increase in accident safety.

To a large extent, U.S. automobile manufacturers have been slow to produce cars that have the maximum possible efficiencies because they question whether consumers will pay higher purchase prices for these cars. Improvements continue to be made, however, at least partly because of the legislative pressure—especially in California—for progress in this direction.

Energy efficiency in industry

The final third of energy use in the United States occurs in a large variety of industrial operations such as producing steam, heating plants, and generating electricity for various operations. Improvements in the efficiency with which energy is used in industry also depends on two principal approaches: the development of more efficient devices and the invention of new kinds of technologies. More efficient motors are now available so that the same amount of work can be accomplished with a smaller amount of energy input. And, as an example of the use of new technologies, laser beam systems that can both heat and cut more efficiently than traditional tools are being given new applications. Industries are also finding ways to use computer systems to design and carry out functions within a plant more efficiently than traditional resource management methods.

One of the most successful approaches to improving energy efficiency in industry has been the development of cogeneration systems. Cogeneration refers to the process in which heat produced in an industrial operation (formerly regarded as “waste heat”) is used to generate electricity. The plant saves money through cogeneration because it does not have to buy electrical power from local utilities.

Other techniques for increasing energy efficiency

Many other approaches are available for increasing the efficiency with which energy is used in a society. Recycling has become much more popular in the United States over the past few decades at least partly because it provides a way of salvaging valuable resources such as glass, aluminum, and paper. Recycling is also an energy efficient practice because it reduces the cost of producing new products from raw materials. Another approach to energy efficiency is to make use of packaging materials that are produced with less energy. The debate still continues over whether paper or plastic bags are more energy efficient, but at least the debate indicates that people are increasingly aware of the choices that can be made about packaging materials.

Government policies and regulations

Most governmental bodies were relatively unconcerned about energy efficiency issues until the OPEC (Organization of Oil Exporting Countries) oil embargo of 1973-74. Following that event, however, they began to search for ways of encouraging corporations and private consumers to use energy more efficiently. One of the first of many laws that appeared over the next decade was the Energy Policy and Conservation Act of 1975. Among the provisions of that act were: a requirement that new appliances carry labels indicating the amount of energy they use, the creation of a federal technical and financial assistance program for energy conservation plans, and the establishment of the State Energy Conservation Program. A year later, the Energy Conservation and Production Act of 1976 provided for the development of national mandatory Building Energy Performance Standards and the creation of the Weatherization Assistance Program to fund energy-saving retrofits for low-income households. Both of these laws were later amended and updated.

In 1991, the U.S. Environmental Protection Agency (EPA) established two voluntary programs to prevent pollution and reduce energy costs. The Green Lights Partnership provided assistance in installing energy-efficient lighting, and the Energy Star Buildings Partnership used Green Lights as its first of five stages to improve all aspects of building efficiency. The World Trade Center and the Empire State Building in New York City and the Sears Tower in Chicago joined the Energy Star Buildings Partnership as charter members and reduced their energy costs by millions of dollars. The EPA also developed software with energy management aids for building operators who enlist in the partnership. By 1998, participating businesses had reduced their lighting costs by 40%, and whole-building upgrades had been completed in over 2.8 billion ft² (0.3 billion m²)of building space. Further efficiency gains were made in subsequent years, and many energy experts argue that the majority of economically profitable efficient savings still remain to be realized throughout both the industrial and private sectors. The EPA’s environmental interest in the success of these programs comes not only from conserving resources but from limiting carbon dioxide emissions that result from energizing industrial plants and commercial buildings and that cause changes in the world’s climate.

Green Market electric utilities

In 1998, restructuring of the electric power utilities opened the market place to “Green Power Markets” that offer environmental features along with power service. Green power sources provide clean energy and improved efficiency based on technologies that rely on renewable energy sources. Educating the consumer and providing green power at competitive costs are seen as two of the biggest challenges to this new market. The Center for Resource Solutions in California pioneered the Green-e Renewable Electricity Branding Program that is a companion to green power and certifies electricity products that are environmentally preferred.

Results and the future

Efforts to increase public consciousness about energy efficiency issues have had some remarkable successes in the past two decades. Despite the increasing complexity of most developed societies and increased population growth in many nations, energy is being used more efficiently in almost every part of the world. Increased efficiency of energy use increased between 1973 and 1985 by as much as 31% in Japan, 23% in the United States, 20% in the United Kingdom, and 19% in Italy. At the beginning of this period, most experts had predicted that changes of this magnitude could be accomplished only as a result of

KEY TERMS

Cogeneration— A process by which heat produced as a result of industrial processes is used to generate electrical power.

Mass transit— Any form of transportation in which significantly large numbers of riders are moved within the same vehicle at the same time.

Solar cell— A device by which sunlight is converted into electricity.

the massive reorganization of social institutions; this has not been the case. Processes and inventions that continue to increase energy efficiency can be incorporated into daily life with minimal disruptions to personal lives and industrial operations. More efficient light bulbs and water heaters, better insulation and more alert, conscious choices about when to use, how to use, and how much to use, are allowing millions of consumers to save energy and money simultaneously. Moreover, U.S. energy efficiency can still be greatly improved without lifestyle hardships; Europeans, who inhabit a similar climate to the U.S., use about half as much energy per person and yet have a comparably comfortable lifestyle and a strong economy.

In December, 1997, in Kyoto, Japan, a global warming agreement—the Kyoto Protocol—was proposed to the nations of the world to cut carbon emissions, reduce levels of so-called “greenhouse gases” (methane, carbon dioxide, and nitrous oxide), and use existing technologies to improve energy efficiency. These technologies apply to all levels of society from governments and industries to the individual household. But experts acknowledge that the public must recognize the global warming problem as real and serious before existing technologies and a host of potential new products will be supported.

See also Alternative energy sources; Fluorescent light; Hydrocarbn.

Resources

BOOKS

Kemp, William H. Smart Power: An Urban Guide to Renewable Energy and Efficiency. Kingston, Canada: Aztext Press, 2006.

Krieth, Frank and D. Yogi Goswami. Handbook of Energy Efficiency and Renewable Energy.NewYork:CRC, 2007.

Rajan, G.G. Practical Energy Efficiency Optimization. Tulsa, OK: PennWell Corp., 2005.

OTHER

Rocky Mountain Institute. “Energy Efficiency: Taxonomic Overview.” 2004 <http://www.rmi.org/images/other/Energy/E04-02_EnergyEffTax.pdf> (accessed December 6, 2006).

David E. Newton