Use of Electric Power Becomes Widespread

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Use of Electric Power Becomes Widespread

Overview

It is difficult to envision a world without electricity, especially in the developed world. Electric lights have allowed us to extend our waking hours beyond the constraints of daylight; electricity powers our factories, computers, stereos, and air conditioning units, pumps our water, and helps us iron our clothes. Yet, until the last part of the nineteenth century, electricity was more a scientific curiosity than a useful phenomenon, and it was not until the second quarter of the twentieth century that electrical power became available to most of the population of the United States, Europe, and parts of Asia. By the end of the twentieth century, most of the world's population had at least some access to electricity, although many areas had limited, unreliable, or no access. This widespread use of electricity was made possible, in large part, by the development of relatively efficient means of generating and using alternating current (AC) which, unlike direct current (DC), can be transmitted over long distances without excessive losses due to resistance in the power transmission lines.

Background

Electricity was first noticed and recorded by the ancient Greeks, who noted that rubbing a piece of amber with wool could cause the amber to shock the person holding it. However, its properties remained a mystery until scientists—including Benjamin Franklin (1706-1790)—began investigations in the eighteenth century. By 1831, Michael Faraday (1791-1867) had discovered electric induction and Hippolyte Pixii (1808-1835) created the first dynamo for generating electrical current the following year. In the 1860s and 1870s a number of scientists and inventors came up with improvements to Pixii's dynamo, but electricity remained confined to the laboratory because there was no real use for it. Lacking a use, there was also no reason to develop efficient means of production or transmission of the electrical energy.

This began to change in the 1880s with the development of both DC and AC electric motors and generators. The primary forces behind these developments were Serbian-American inventor Nikola Tesla (1856-1943) and the American Thomas Edison (1847-1931). Tesla first developed an AC motor and generator in 1883, bringing it with him to the United States the following year. He worked briefly for Edison, later leaving to work on his own. In 1885 he sold his inventions to George Westinghouse (1846-1914), who launched the first large-scale attempt to generate AC electrical power.

In so doing, Westinghouse and Tesla ran afoul of Edison, who was promoting his own DC electrical power systems. The struggle was acrimonious, with Edison proclaiming the dangers of alternating current (pointing out that it was used in electric chairs) while Tesla and Westinghouse pointed out that DC could not be transmitted for long distances without substantial inefficiencies. In fact, the greater efficiency of AC generation and transmission eventually won the day, resulting in one of Edison's few defeats. In addition, it turns out that AC motors can be made lighter, more efficient, and less expensively than DC motors, adding to their advantage.

By the year 1900 the electrification of the United States, Europe, and Japan was beginning, and, by the 1930s, much of the rest of the world was beginning to construct power-generation stations. This trend has continued through the present and, even today, increasing use of electrical power is the norm in virtually every nation on Earth. It is nearly impossible, with the exception of small populations in parts of South America, New Guinea, and Africa, to find people whose lives have not been touched in some way by electricity, whether in the form of products, electric lights, or radios. Regardless of the many different means of generation, electrical power seems likely to remain the most widely used form of energy on Earth for decades to come.

Impact

Electric motors have helped to make mechanical power portable and accessible. Prior to the development of electric motors, mechanical power consisted of muscles (human or animal), gravity (in water wheels and similar devices), wind, or steam (in the form of large steam engines). In many cases mechanical power was impractical because of physical or geographic constraints. For example, gravity-powered devices such as water wheels require running water nearby, making them impractical in the desert. Muscle power could work well for many projects, but had its limitations, too. Horses, for example, could be teamed together to pull heavy loads, but required relatively level surfaces and enough room to operate. Other sources of mechanical power suffered similar limitations.

Electric motors began to change this. Turning a saw in a sawmill no longer required a nearby stream or river when an electric generator could provide sufficient current to turn an electric motor continuously, regardless of weather or water supply. Virtually unlimited power was available at any time simply by running wires or bringing in a generator to wherever work needed to be done. As well as making mechanical power portable, electric motors could out-perform both man and animal. Lifting and moving heavy loads could be done more easily and more reliably than before without the resulting risk to life and health.

In addition to these advantages, electric motors were more easily controlled than teams of either humans or animals. Since the torque and power output of an electric motor can be precisely controlled, the mechanical power provided by these motors could be harnessed and controlled with a much higher degree of precision than before. While this level of control is relatively unimportant for cutting lumber or pulling heavy loads, it is vital for the development of precision objects. Too, the fact that electric motors can be made almost arbitrarily small allows this same precision at almost any scale, making possible near-microscopic motors and mechanical devices that are beginning to play an important role in modern technology.

Electric motors are also important in operating pumps. While seemingly mundane, pumps are vital to modern society. For example, pumps supply water to boilers that make steam for electric generators to power our civilization. Massive pumps supply drinking and fire-fighting water to cities while smaller pumps supply gasoline to our automobile engines. Pumps of another sort, called compressors, run our air conditioning systems, smaller versions of which circulate coolant through high-performance supercomputers to keep their electronics from melting. Other electrical pumps circulate blood through heart-lung machines during open heart surgery, helping surgeons to repair damage that would otherwise be fatal. Virtually every system designed to move a fluid, whether liquid or gaseous, relies on pumps or fans, most of which are powered by electrical motors similar to those first designed by Nikola Tesla.

Powering these motors, of course, is electricity from a generator of some sort. While there have been many alternate methods of energy production in the last few decades, the overwhelming majority of the world's electrical power comes from dynamos similar to those invented in the latter part of the nineteenth century. It is also interesting to note that, from an engineering and theoretical standpoint, electric motors and generators are nearly identical and, in fact, "motor-generators" exist that operate equally well as motors or generators, depending on the direction of electrical current flow.

In any event, all of the benefits accrued from electric motors would fail to exist if there was no reliable way to generate electrical power in the first place. However, electrical power generation reaches much further than simply providing a power supply for motors. Everything that makes modern life comfortable for inhabitants of the developed world is dependent in part or in whole on the presence of relatively cheap and reliable electrical power.

Much of the impact of electricity on society came from the rural electric cooperatives, first in Japan and Germany and later in the United States and Europe. These cooperatives banded together to build power stations, run lines, and power the farms. Grain crushers, threshers, milking machines, food storage and preservation, and other machines became possible, removing much of the drudgery from farm life while making farms more efficient.

At the same time, widespread electrical power was making life in the cities healthier and more comfortable. Refrigeration made it possible to keep food fresh for several days while freezers kept food fresh for weeks. This made daily trips to the market a thing of the past, which, along with household devices, began to free women from their traditional roles as homemakers. Electric elevators and escalators have made high-rise buildings possible, completely changing the layout and skyline of the world's major cities. Meanwhile, computers, wholly dependent on an uninterrupted supply of precisely conditioned electrical power, have had (and will continue to have) a profound effect on virtually all aspects of technological society. Lest one argue that these impacts are limited to the developed world, with its plenitude of electrical power, it is worth noting that many developing and less developed nations are actively pursuing expansion of their domestic electrical power systems.

The negative side of this increased use of electrical power is the environmental toll it has exacted. Burning fossil fuels has led to air and water pollution, along with possible long-term effects on global climate. Damming rivers for hydroelectric power production has flooded parts of America's Grand Canyon, forced the rescue of Egyptian temples and statues, and necessitated the relocation of millions of Chinese peasants. And, of course, the extraction of fossil fuels for energy production has led to strip mining, land subsidence, acid mine drainage, and other environmental insults. In addition, by enhancing so many aspects of our lives, electrical power helps to enhance human health and prolong life. Ironically, this has resulted in steady and rapid population growth in many parts of the world, further straining the terrestrial environment and threatening to reduce the quality of life for so many.

P. ANDREW KARAM