Where We Get Our Power
THE electrical power consumed by many families today is simply fantastic. For example, to operate only an electric frying pan and a television requires power equivalent to that exerted by a team of two pulling horses! And that is a lot of power. For an average workhorse will pull on its harness with a force of 180 pounds.
Electrical power is measured in what are called watts and kilowatts. A television draws 300 watts of power, and an electric frying pan 1,200 watts. Other appliances need even more power—a laundry dryer nearly 5,000 watts and an electric range over 12,000.
The amount of electricity used is measured in kilowatt-hours. Thus a kilowatt-hour represents the work done by one kilowatt of electricity during one hour’s time. But how much work will a kilowatt do in an hour?
It will do an amazing amount. In one hour it has been calculated that a workhorse will do the work equivalent to lifting 1,980,000 pounds one foot off the ground. A kilowatt of power in one hour will do about one third more work than even that.
Consumption and Cost
The average family in one section of New York city consumes daily, on the average, 17 kilowatt-hours of electricity, or nearly 23 horsepower-hours. That means an average family uses nearly as much electrical power as a horse would produce working around the clock, day in and day out, without ever stopping or getting tired.
In parts of New York city this power costs a family slightly less than 3 cents a kilowatt-hour, or not quite 50 cents a day for 17 kilowatt-hours. In certain other parts of the country, however, that amount of electricity costs much less—only about a penny per kilowatt-hour. Also, as consumption goes up, cost per kilowatt-hour goes down. Thus large industrial consumers pay only a fraction of what small consumers do.
The demand for this relatively inexpensive, easy to utilize form of power has been phenomenal. In 1970 the United States consumed some 1,550,000,000,000 kilowatt-hours—about five times the amount used in 1950! From 1969 to 1970 consumption leaped 9.2 percent. The United States produces about 35 percent of the world’s electric power, and the Soviet Union 15 percent.
In the United States, industry is the largest consumer. According to the Edison Electric Institute, industry uses about 41 percent of the electricity produced. Another 32 percent goes for residential use, while 23 percent is used by stores, shopping centers, office buildings, hospitals and other commercial concerns. The final 4 percent operates streetlights, subways and the like.
From where does this fantastic amount of electrical power come?
How Electricity Is Produced
Most electricity is produced from what are called “fossil fuels”—oil, coal and natural gas. These fuels are burned at power-generating plants in huge furnaces. The furnace heats a water boiler to produce a superheated steam. The steam then rushes at 1,000 miles an hour into a huge turbine, and spins its bladed wheels. In hydroelectric plants, falling water, instead of steam, is used to turn the turbine. The turbine then drives a generator to produce electricity.
Over 80 percent of the electricity in the United States is produced in steam-turbine plants, while hydroelectric facilities generate most of the rest. The first steam-turbine electric plant went into operation ninety years ago in New York city. Today there are some 3,400 power plants throughout the country.
Actually the steam-turbine process of producing electricity is rather inefficient In the conversion process only about one third of the energy of the coal, oil or gas is turned into electricity. The other two thirds of the energy escapes in the form of waste heat and other pollutants. Also, up to 20 percent of the generated electricity is lost in its transmission from the power plant to the place of use.
The fossil fuel consumption of electric power plants staggers comprehension. A large coal-fired plant may burn over 600 tons of coal an hour! Coal is used to generate nearly half the electricity in the United States, and falling water, natural gas and oil produce most of the rest.
Of course, electricity is only one form of power. There are also increasing demands for power to run automobiles, fly airplanes, provide heat for homes, and so forth. For these purposes oil and natural gas are the principal energy sources.
Harm to the Environment
Of these various fuels, coal is the most damaging to the environment. For example, a Virginia Electric and Power Company plant, which consumes some 10,000 tons of coal a day, generates about 60 tons of fly ash and about 20 tons of irritating sulfur dioxide gas every hour, most of which is spewed into the air! Earlier this year legal action was announced against the Delmarva Power and Light Company in Delaware City for belching out 74,000 tons of sulfur dioxide each year.
Describing the air pollution problem, James R. Schlesinger, Chairman of the Atomic Energy Commission, noted recently: “Fossil-fuel [electric power] plants contribute the bulk of sulphur oxides in the atmosphere and a very substantial proportion of the nitrogen oxides—to say nothing of the particulates [solid matter].”
Also a factor in damaging the environment is the way coal is mined. Last year about 44 percent of the coal was strip-mined, desolating tens of thousands of acres of some of the most beautiful mountain country in the United States. Typical of the recent protests against this practice is that of congressman Ken Hechler, who said this February:
“The coal and power barons and certain Western legislators are trying to subjugate the people of the Appalachian states and rip up our hills and pollute our streams to serve the power-hungry needs of the big cities. We have reached the point where we’re going to stand up and fight against this policy.”
Yet a switch from the use of coal in electric plants, which New York city completed this year at considerable expense, does not solve the problem. For oil and gas also pollute. The sulfur content of oil, too, is poured into the air, and natural gas emits oxides of nitrogen when burned. And there is also the problem of the waste heat from electric plants that is discharged into nearby rivers and lakes, at times dangerously raising their temperatures.
Is the present power crisis due to this threat to the environment? Or, are there other factors that are even more serious?