Copyright 1995 by Ralph Nansen, reproduced with permission
Table of Contents
Chapter 7: Electricity: The Energy Form of the Future
Since the beginning of man’s experience on this earth, he has stood in wonder and fear as lightning laced the sky and thunder drove the terror of the unknown into his soul. What was this fearsome force that could make night like day, strike great trees asunder, burn forests, and occasionally strike a victim dead in its path? The ancients attributed this frightening phenomena to the wrath of their gods. It was not until the eighteenth century when Benjamin Franklin conducted his famous experiments that fact started to find its way into the mystery of lightning.
For most people at that time electricity still carried that strange mysticism. What good could it be? What could it be used for? It was a scientific curiosity for many years, but after the start of the nineteenth century our comprehension of its potential began to grow rapidly.
The real understanding of electricity started in 1800 when Alessandro Volta produced the first electricity from a cell made of zinc and copper plate. This was the first battery, but it was much more than that. Of greater significance was the accompanying discovery of electrical current, which began the development of modern electrical science and industry. In Volta’s honor the term “volt” was given to electrical pressure, or electromotive force. In the early days of the century the only source of direct current was from primary batteries of the type Volta had invented, and they were used extensively.
Later, in 1819, Danish physicist Hans C. Oersted discovered electromagnetism. In 1820, Andre Ampere defined the laws of electrodynamic action, and in 1821 Faraday discovered the fundamentals of electromagnetic rotation. In 1827, George S. Ohm made his contribution when he formulated Ohm’s law, which defined electrical current potential and resistance. This was all put together in 1829 by American physicist John Henry when he constructed an early version of the electromagnetic motor. This was the beginning of making electricity perform useful work. The first effort to propel railroad vehicles by electrical batteries was made in 1835, but it was not until 1879 that E. W. Siemans exhibited the first successful electric tram at the Berlin Trade Exhibition.
Electricity branched off into the communications world in 1833 when K.F. Gauss and Wilhelm E. Weber devised an electromagnetic telegraph that functioned over a distance of 9,000 feet. Wheatstone and W.F. Cooke patented an electric telegraph in 1837, but it was Samuel Morse who exhibited his electric telegraph at the College of the City of New York in the same year, receiving a $30,000 grant from Congress to build the first telegraph line from Washington DC to Baltimore. It was used for the first time in 1844. The electric telephone was brought into existence by Alexander Graham Bell in 1876, and the world suddenly became much smaller.
By the time Thomas Edison and T.A. Swan independently devised the first practical light bulbs in 1880, electricity’s future was secured. Edison was also the man who did the design of the first hydroelectric power plant, which was built at Appleton, Wisconsin, in 1882. The first English electric power station was established at Deptford in 1890. Niagara Falls became more than just a honeymoon site when hydroelectric installations were begun in 1886 and delivered their first power in 1896.
The scene was set for the twentieth century to become the century of electricity. New uses were discovered steadily, and there seemed to be no end to what electricity could do. Communication systems depended on it, and transportation became involved with electric trolleys, buses, trains, subways, and a few cars. The wheels of industry started to turn with the torque of electric motors. Aluminum was changed from a metal once so precious that Napoleon had his tableware made from it, to a metal so common we now use it for beer cans, pots and pans, window frames, and airplanes.
The first all-electric city, a place with no chimneys, was built as a model at Grand Coulee Dam in the mid 1930s. It demonstrated the flexibility of electricity to perform all household energy chores more than half a century ago. Since that time, technology has made great strides, and today we take for granted the many tasks it can accomplish at very high efficiencies.
The Flexible Energy Form
Through the years, the portion of our total energy use supplied by electricity has steadily grown from about 12% in 1945 to more than 30% in 1980. This trend is on an accelerating rate for two fundamental reasons. First is the great flexibility of electricity to do nearly any energy job due to the high grade of electrical energy. Second, as the cost of oil rises, the cost of electricity has risen more slowly because only a small fraction of our electric power is now generated with oil. The rest comes from coal, natural gas, nuclear, and hydroelectric dams.
You are probably asking yourself what the term “high-grade” energy means. It might be easiest to start by defining low-grade energy. Low-grade energy is typified by heat at relatively low temperatures such as that found in the heating elements of our hot water tanks. Low-grade energy is useful to heat water for our homes, but not very useful for anything else.
As we move up the scale of energy and consider high-temperature steam as an example, we find that it can do many things. It can run engines and provide process heat, among other things. When we look at electricity, we find it is the highest grade energy of all because it can do nearly anything. Electricity can provide thousands of degrees in the arc of a welding torch, activate the sensitive heating elements that defrost our car’s rear windows, run the quiet motor of the refrigerator-freezer in the kitchen, control the ever-watchful thermostat maintaining our comfort, bring us lilting stereo music in the living room, energize the comforting whirl of our car’s starter as it brings the engine to life, light our Christmas tree, bring us the sound of our children’s voices from far-off places, show us the thrill of an Olympic winner from halfway around the world, light and heat our homes, and run the power tools that make life so much easier. In the United States more than 98% of all physical work is done by machines. Most are powered by electricity. Can you think of any other energy form that can perform the variety of functions within the capability of electricity? There simply isn’t any.
The Clean Heat
Now that you are an expert on the grades of energy, it might occur to you to ask: “Why does it make sense to use a high-grade energy like electricity to do a low-grade energy job like heating my home?” That is a very sensible question and has more than one answer. First, if you have low-grade heat available from solar energy or leftover heat from the local foundry, it only makes sense to use it. However, the great advantage of high-grade energy is its ability to appear in many guises. Most of us think of glowing coils of wire hanging on a ceramic housing in our portable electric heater when we think of electric heat. That is certainly where electric heaters started, but much has happened over the years. Using the same principle of electrical resistance in a wire, the original electric heaters have emerged as baseboard heaters, forced-air furnaces, or hot water furnaces. They have provided clean, quiet, labor-free heat to millions of people. They do suffer inefficiencies in the process, which has stimulated engineers to find a new way to turn high-grade energy into heat at very high efficiencies.
Their efforts have produced a very efficient device called the heat pump. It is just an air conditioner running backwards—not the machinery, but the airflow. The concept is very simple. It takes cool air from outside, raises its temperature by passing it through a heat exchanger that is heated by compressing a working fluid in the heat pump with mechanical energy, extracts some of the residual heat to be used inside, and then exhausts the cooled air back to the outside. In this mode, it is a heater. If you reverse the process, it is an air conditioner. The system can be made to work at very high efficiencies. There is no wasted heat going up the smoke stack, there are no combustion products to foul our environment. Heating or cooling is there with the flick of a switch. No need to call an oil truck to fill the tank. No sweaty, dirty job of shoveling coal into the coal bin as I did when I was a child. No worry about the pilot light going out on a gas furnace. With the simple act of setting a thermostat we enjoy a clean, comfortable environment.
Near the turn of the century when horses were being replaced with the infernal machines of man’s creation, there was no clear consensus of what kind of engine would power these machines. Some were powered with internal combustion engines using gasoline as fuel. Some had steam engines. Some were electric with battery power. The competition raged for several years, with advocates of each touting their advantages. In the end, the winner took all. The flexibility, range, performance, and low cost of the gasoline-powered automobile could not be matched by its competitors.
This great dominance of the personal transportation market reached its peak during the 1960s and early 1970s. Gasoline was so cheap it did not really matter how much was burned. Cars were big, heavy, and luxurious with powerful engines. It was the era of muscle cars with 442- and 454-cubic-inch displacement engines that could develop more than 350 horsepower. My 1968 Firebird 400 did not even begin to run well until it reached 75 miles per hour. What auto company would even consider spending money to develop an electric car in that kind of environment? Or for that matter, what US car manufacturer would even seriously approach the development of a high-efficiency, lightweight, high-mile-per-gallon, gasoline-powered car? Certainly there would be very few buyers for them at that time.
Since then, fuel cost and availability, environmental controls, and inflation have changed all of that. As we look into the future and the new energy era based on nondepletable electricity generation, it is time to reevaluate the capability of the electric car. Many years have passed and significant progress has been made.
Battery technology has come a long way since Volta’s first cell of zinc and copper plate in 1800. That first cell was a crude example of what is now called a primary cell. It was like the dry-cell flashlight batteries of today in that it could not be recharged. The secondary or storage cell had its real beginning in 1859 when the French physicist Gaston Plante is believed to have made the first practical “acid” storage battery. Storage batteries are a way of storing electrical energy as chemical energy and then delivering the energy later as electricity. They can then be charged again and again, cycling between electrical energy and chemical energy, back and forth and back and forth.
Thomas Edison invented the nickel-iron-alkaline storage battery in 1908, and through the ensuing years the two main types that evolved were the lead-acid and the nickel-iron-alkaline cells. They both operate on the same general principle but differ in their materials and characteristics. The lead-acid battery has become the one with which we are most familiar since it is used in our automobiles. In recent years we have also seen increasing use of nickel-cadmium-alkaline storage batteries, which were used extensively in Europe before their introduction to the United States.
Today batteries play an important part in our lives. Dry cell primary batteries power our flashlights, toys, cameras, personal stereos, and a multitude of other devices. Rechargeable storage batteries provide portable energy for a vast spectrum of electronic marvels, such as cellular telephones, laptop computers, and battery powered tools, as well as starting our cars and powering our golf carts. The potential of battery-powered automobiles in the future has brought new emphasis to advanced developments.
Lead-acid batteries are probably reaching the practical limits of their development since they have been in continuous use for so many years in the automobile and marine industries, as well as being used extensively in deep-cycle applications for forklifts and golf carts. Even so, they are the yardstick by which we can measure other developments, and lead-acid cells can be used effectively in battery-powered cars as long as the range requirements are modest, probably about 50 to 100 miles. General Motors is testing a new lead-acid battery-powered car called Impact that has performance comparable to many small sport coupes. It has a 70- to 90-mile range with current batteries. The designers think that new battery developments will double that range by 1998.
Edison’s nickel-iron batteries are also being developed for use in a new, limited-production, electrically powered Chrysler minivan that will have a 100-mile range and a top speed of 65 mph. The expected life of the batteries, using overnight charging, would be 100,000 miles.
Another battery development that is favored by many for electric cars of the future is the sodium-sulfur technology battery. These batteries have twice the power density of lead-acid batteries. A new world distance record was set by a Swiss-built two-seat car, which traveled 340 miles at an average speed of 74.4 mph. Even though it had been specifically built for this test, it was a very impressive demonstration of the future potential of electric cars with sodium-sulfur batteries. Several major manufacturers now are using them in their prototypes, such as the Volkswagen Chico, Ford Ghia Connecta, and BMW E2.
Research is continuing on nickel-cadmium batteries. Other material combinations are also being investigated along with techniques to further improve the known material combinations. Life, weight, cost, charging rate, and safety are all important parameters to be considered.
Let us put ourselves into the picture as Mr. and Mrs. Average American and see what kind of electric car we would need in the future if we wanted to maintain at least our current standard of driving. What kind of driving do we normally do and how far do we drive?
We drive to work and home again. We go to the grocery store and to the shopping mall. We go to a ball game occasionally and stop by a friend’s house whenever possible. The kids use the car to go to school functions and probably do a little street cruising afterwards. We drive to the other side of the state to see relatives at least a couple of times a year. We drive to Disney World in Florida for our vacation. We also like to go to the movies regularly and maybe go fishing in the summer.
When we add it all up, we find that of the total miles most people drive in a year, 50% is on trips of less than 20 miles and 70% is on trips of 50 miles or less. That means that by far, most of our driving is accomplished locally. Even with today’s battery technology, it is practical to design and build a battery-powered car with a 50-mile range. Several experimental models have already been built. Some are being put into limited production. As mentioned earlier, advances in battery technology are certain to extend the useful range as the market develops for electric cars and new-technology batteries are placed into production.
This means that we could eliminate at least three quarters of the gasoline consumption used in private cars if we replaced them with electric cars based on available technology. Since transportation uses more than half of all our oil and private autos use two thirds of all transportation fuel, that would amount to an elimination of one quarter of our total current oil consumption—if we generate the electricity without burning fuel.
In our imaginary role of Mr. and Mrs. Average American, we will keep one of our gasoline-powered cars for a while to use on those long trips but buy a new electric car to do all our commuting and around-town driving.
Even the cost to drive an electric car can be less than for a gasoline-powered one. If we drove at 55 mph, the electric car would use about 20 kilowatts of battery power in an hour, which would require 30 kilowatts to recharge. In other words it would use a little more than half a kilowatt hour per mile. If we paid eight cents per kilowatt hour for electricity, that would be four cents per mile for the “fuel.” This is comparable to what we would pay for gasoline for a small car if we got 30 miles per gallon and paid $1.20 per gallon of gasoline. In the time frame we have been considering, gasoline will probably cost anywhere from $2.00 to $4.00 a gallon (which is the price of fuel in the rest of the world in 1995). If we consider $3.00 per gallon as a likely cost in this time frame, the mileage cost is 10 cents per mile, or two and a half times higher. Battery life and replacement costs are the key economic questions that can only be answered conclusively with real experience and the passage of time, but to an engineer, the answer is already clear. The days of the gasoline-powered automobile are numbered, if we can provide low-cost electricity from a nondepletable source.
In the area of heavy transport, the most promising candidates for electric power are railroads. A few railroads in the US are already electrified, but they are a very small percentage compared to diesel locomotives. In England and Europe many of the railroads are electrified. They developed this way because cheap oil resources were not available and it was more economical for them to generate electricity with coal or stationary nuclear power plants than to import oil. There is no reason, except for the capital costs of conversion, that the US could not change to electricity, if we develop nondepletable electric power generation—and particularly if the US were to use the English system with the conductors mounted alongside the rails so there are no visually objectionable overhead wires.
Trucks, buses, aircraft, and ships are a much tougher problem. The most likely solution would probably be the continued use of oil in some cases, synthetic fuels, or in the future, the use of hydrogen made from water by electrolysis. This segment of energy use is probably the most difficult to convert to electricity; however, it represents only about 12% of our total energy consumption, so remaining oil reserves or synthetic fuels should be able to supply the future demands as we continue our search for an alternative solution.
Concepts for the Future
It is likely that as technology is developed and the range of battery-powered cars is extended, long distance travel would become practical. If you drove up to the service station of the future just off the interstate, the “fill-‘er-up” request might be a quick exchange of battery packs, with the depleted pack unplugged and slid out onto a service cart and a freshly charged pack slid in as a replacement. After the exchange you would be ready to go again even before the kids are back from the restroom.
Some of the developments being investigated include hybrid systems using flywheels to help store energy for extra acceleration and recovery of braking energy, or small internal combustion engines to work with the battery system for long-range vehicles. In today’s cars there is no way to recover the energy expended by the brakes. This energy is lost as heat. In an electric car with the right kind of design, a very large percentage of normal braking energy could be returned to the batteries. Only in the event of very rapid stops would the energy be lost as it is today.
The technological progress that has evolved through the years now makes it possible to develop efficient, reliable, and reasonably priced control systems so necessary for the practical development of electric vehicles.
I have been talking about battery-powered cars because they are the most logical development using what we know today. That does not mean that as the shift to electric cars occurs, the stimulated fertile minds of the next generation will not come up with some breakthrough in the storage of electric power. The economic motivation will be there to find a better mousetrap. I foresee that improvements would evolve rapidly after the switchover to electric cars begins.
One potential alternative energy storage system is flywheel batteries instead of chemical batteries. One company based in the state of Washington is developing such a system. They are projecting ranges of up to 350 miles between recharges with a weight less than a chemical battery. If they succeed it will be a tremendous breakthrough.
As we look into the future of long-distance and heavy highway travel, one of the things that might develop would be the electrification of the interstate highways. This could be done by burying the electric power system in the roadway and having the energy transmitted by induction or radio frequency wireless power transmission to power the vehicles. If this could be done efficiently, then even the trucking industry could use electric drive. This step is not as far off as you might think. Prototype bus systems are already being tested. They transfer electrical energy by induction as the bus stops for passenger pickup.
There would undoubtedly remain many applications that could best be served by the internal combustion engine or gas turbine engines, such as farm tractors that plow the fields and airplanes that ply the sky. However, since much of farming is now being oriented around automated sprinkler systems that rotate about a central pivot and form circular patterns across our great land, why couldn’t we have an electric tractor cultivate this circular field using an extension cord from the central pivot for power transfer? Why not indeed? Maybe we could also build an airplane that only had to have enough fuel for takeoff and landing. After takeoff it would climb above the clouds and there switch over to laser-furnished power beamed down from a solar power satellite for the cruise phase of flight. Does that sound farfetched? Yes it does, but a few years ago Abe Hertsberg and a team of students at the University of Washington made a study of the concept and believe it could be made to work.
Another aspect of converting to expanded use of electricity will be the need for more large-scale electrical distribution lines. These lines already exist throughout the country, but they take up large swaths of ground as the towers and wires wander across the countryside. It would be very desirable to eliminate these rather than expand the number. Modern technology may be ready to provide a means to accomplish that goal in the future. We have all seen the announcements of breakthroughs in the development of superconductors that no longer require cryogenic temperatures. If these materials can be developed in sufficient quantities and at low enough cost, they could be used to replace the overhead distribution lines with buried superconductors requiring very small right-of-ways. Even if some refrigeration was still required, they could have better overall efficiency than current high-voltage overhead lines. It is an intriguing idea and one that could have far-reaching implications for our electrical future.
Manufacture of Liquid Fuels
A much more likely course for some of the more difficult conversions will be the use of synthetic fuels or fuels made with the use of electric energy. Hydrogen is the cleanest burning of all fuels, and it can be made from water through the simple process of electrolysis. If you took high school chemistry, you have probably made hydrogen in the lab. Excess power available from solar power satellites during periods of low demand could be used to generate hydrogen. The hydrogen could be liquefied at cryogenic temperatures (minus 423 degrees Fahrenheit) for denser storage or could be absorbed in newly developed solid devices that are proving to be very efficient for storing hydrogen. Some studies have been conducted on using hydrogen gas piped through existing natural gas distribution systems as a replacement for natural gas. This option is possible for the future, but the more likely economical solution will be to use electricity directly since it can do anything that natural gas can do, and with the advent of the modern heat pump, work at very high efficiency.
Other developments are going on in conjunction with ground-based solar power that use the intense heat of concentrated sunlight to produce synthetic fuels or hydrogen without going through the electrolysis process. By the time the satellites can provide large increases in the amount of electricity available from a renewable source the technology to utilize it will be available.
The Changing Energy World
I am sure you are beginning to get the picture of a world that is very different from what we now know. You are correct in that feeling. We are near the end of an era. If we are to be a free, dynamic, and economically expanding nation, we must recognize that change must be made if we do not want to wither away with a dying era. Change is always difficult, but at the same time, it is always challenging and full of opportunities. It will not happen overnight but will cause major shifts in business and jobs. Some businesses will no longer be needed while others will spring up in their places. The internal combustion engine mechanic will have fewer and fewer engines to repair while the electrical and electronics repairman will be in great demand.
As we move into the next energy era we can look forward to the time when electricity will supply 85% to 90% of all our energy use. This will make the energy contribution needed from liquid fuels well within their capability. They could be the products of biomass conversion, synthetic fuels, oil pumped from the ground, hydrogen made from water, liquefied natural gas, or some new source.
Imagine the change in our environment as we convert from burning fossil fuels to the clean nonpolluting energy of the sun. We will be able to eliminate smog, high carbon monoxide levels, high carbon dioxide levels, acid rains, and the industrial haze that covers the states east of the Mississippi River. We will be moving forward with a legacy of clean air for our children. We will also be giving them the abundant energy they will need to exercise their dreams of making a better life without the chains of scarcity holding them back. They will be powered with electricity, the energy form of the future.