Author note: This is the first solar energy article that I wrote. It was written in the late 1960s - not sure exactly which year, but 1969 would not be far off the mark.

SOLAR ENERGY "FARMS"

By Hal Mansfield

Introduction:

You are flying over the desert near Yuma, Arizona, ten years from now. As you look down you see countless rows of what seem to be large black pipes, each several miles long. Positioned above each pipe, you can see transparent glass structures. Thousands of square miles of desert are covered by what you see. In the middle of this enormous complex stand several huge buildings. Beside these buildings are located some large circular silos which appear to be storage tanks of some sort. What is there about this remote desert area that would induce man to build so elaborate and extensive a complex here?

You are looking at a solar energy "farm." It is the result of the work of Aden B. and Marjorie P. Meinel. Professor Meinel is Chairman of the Department of Optics at the University of Arizona at Tucson and President of the Optical Society of America. Mrs. Meinel is returning to a career in science now that the Meinel children are grown. She had done work in astronomy and volcanic origins before turning to solar energy research.

The Meinels came to believe in the potential usefulness of the sun as a source of energy after noting the present energy crisis and viewing the adverse ecological effects caused by conventional energy sources.

The energy crisis:

The need for great amounts of energy to run our highly technical society has already resulted in an energy crisis. The number of power blackouts and the much more frequent power "brownouts" continues to grow. Even more energy, mostly in the form of electricity, will be needed in the future, both because there will be more people and because there will be more electrically run conveniences in our lives. The big question is: Where will the energy come from to produce this electricity? As yet, no clear answer to this question has emerged.

The Meinels believe solar energy farms can be built, using technology and materials currently available. They believe a series of solar energy farms located in several different spots in the southwestern United States could provide all of the electrical energy needs of the entire United States by the year 2000. They have selected sites in the Southwest because the sun shines on these places with great intensity and because cloudy days seldom occur.

How a solar energy farm works:

As planned, the solar energy farm will consist of a series of large, very long tubes. These tubes are one-way filters. They let in the heat producing energy of the sun and hold that heat within the tube. To increase the heat absorbed by the filters, a special kind of lens, called a Fresnel lens, will be placed above each tube. These leases will gather sunlight, thus multiplying the energy focused through the filters.

The lenses will automatically follow the sun as it moves across the sky, gathering the maximum energy available from the sun at all times. Inside the large filter-tubes and positioned to absorb the heat generated by the lens-filter system will be smaller tubes containing nitrogen or a similar gas with excellent heat absorbing and heat holding properties. As the gas is pumped through the lens-filter system, it will be heated to between 800° and 1100° Fahrenheit by the sun's rays.

The gas will then be pumped out of the lens-filter system into two other areas. In one area, the gas will be used to turn water into steam. To accomplish this, the pipes containing gas will be interfaced with other pipes containing water. Heat from the gas filled pipes will be absorbed by the water filled pipes. When the water in the pipes reaches the critical temperature, steam will result. This steam will be used to operate turbines which will generate electric power.

The second area will be a storage area. Here, the gas itself will be stored or it will be used to heat another substance with better heat retaining capabilities than the gas provides. This stored material will be used to operate the system on cloudy days. Of course, the reserves would also operate the system at night.

In summary, the sun creates heat, the heat is captured and used to turn water to steam, the steam runs the turbines which generate electricity. It sounds simple and it is. All of the elements necessary for the system presently exist. They simply have not been put together before in the form envisioned by the Meinels.

Extra dividends:

Not only will the Meinel solar farms provide enough electric energy for the entire population of the United States, but they will also provide sufficient surplus energy daily to desalinate seawater to serve the fresh water needs of 120 million people. In addition, enough surplus solar energy will be available for release back on the desert so no unwanted climatic or other adverse environmental changes will occur.

A third dividend, and an important one, found in solar energy farms is that they avoid the critical problems and adverse environmental effects created from the use of water power, fossil fuel power, or atomic reactor power to generate electricity. Let's examine more closely some of the drawbacks solar energy farms avoid.

Water power drawbacks:

Traditionally, electricity has come from generators powered by the water spillways of great dams. We now know that dams can be highly destructive to the environment. When the ecology of a river system is upset by a dam, many environmental changes may occur. Past experiences suggest most of these changes are ecologically bad. It is therefore unlikely that enough more dams with power plants can be built to provide future electrical needs without serious damage to the environment, even if a sufficient number of prime sites remained.

Fossil fuel drawbacks:

The use of fossil fuels to run power-generating plants is now the most common way of generating electricity. Fossil fuel plants also have adverse environmental impacts. First of all, the coal and oil furnaces emit large amounts of pollutants into the air. These pollutants contain materials which add to smog problems and which can harm mankind and other living things. Such emissions are also eye-sores; the large smoke stacks belching forth smoke and other contaminants are often visible from miles away.

Even where reserves are found, the mining of coal and the drilling of oil can spell environmental catastrophe. For example, offshore drilling of oil has already resulted in several large oil spills causing great concern and expense. Controversy surrounding the opening of the Alaska oil fields is causing deep divisions between environmentalists and the oil industry. Strip mining of coal has become a highly controversial issue since vast acreages are laid bare as the coal is mined.

These raining scars, traditionally left to heal by themselves, are unsightly to see. The land is generally not reusable, at least for several generations. Nature, in terms of vegetation and animal life, suffers great losses. Even when efforts are made to re-landscape the land laid bare by strip mining operations, many years and much money are needed to restore the beauty and productivity of the land.

When all other arguments are by-passed, there remains the inevitable fact that fossil fuel resources and reserves are rapidly dwindling. In time, perhaps in a generation or two, there will be no more fossil fuels. When they are gone, they are gone forever.

Atomic power drawbacks:

Partly because of the fossil fuel shortages and partly in a search for cheaper electricity, the utilities industry has turned to atomic power as a possible way to meet future needs. Twenty-three atomic power plants have been built and are in operation. Many more are under construction or on the drawing boards. As many as one thousand atomic power plants might be in operation by the year 2000. Several thousand such plants would be needed in the 21st century to supply the needs of the U. S. alone.

Unfortunately, atomic plants create many problems, perhaps more than they solve. The most serious danger is from an accident atomic experts call the "China syndrome." This accident could occur in any plant if both the normal water-cooling system for the atomic pile and the emergency water-cooling system failed. Recent evidence suggests both systems could fail at once because of design shortcomings.

Without water to keep it cool, the atomic pile would get hotter and hotter. Once the pile heated enough, it would melt its containing walls and fall to the ground. On the ground, the pile's immense heat would cause it to tunnel straight down several hundred feet (thus the name "China syndrome") over a period of a month or more. All the while, nothing could be done to stop the pile's action, to contain radioactive contamination, or to protect the people living near the plant at the time of the accident.

It has been estimated that several thousand people might die from radiation poisoning if such an accident occurred. Moreover, the probability of such an accident happening appears quite high according to recent testimony given at Atomic Energy Commission hearings on nuclear power plant safety.

Second, there is the matter of radiation "seepage." Radiation has accidentally escaped from several atomic facilities across the country. In each case, the escaped radiation apparently was not sufficient to cause immediate, significant environmental damage or to injure the human population. Perhaps this luck will not hold in the future. As with the China syndrome, the danger is ever-present and cannot be fully overcome. Radiation is a part of the atomic reaction process.

Third, great amounts of water are needed to cool the atomic reactor pile. Because of the great volume of water needed, the atomic power plants have been built on large rivers. Cold water is taken into the system above the plant. As it is used to cool the reactor pile, the water becomes very hot. The hot water is then returned to the river.

Releasing the heated water back into the river creates thermal pollution. That is, the temperature of the entire river is significantly raised. Such a rise in temperature can kill fish and other useful aquatic life and, at the same time, encourage the growth of organisms which foul the water and otherwise detract from its usefulness. No reasonable alternative to this method of cooling the atomic plants has been developed or seems likely. Serious environmental damage may be the ultimate result.

Finally, and most importantly, there is the matter of disposing of the waste products which occur when the atomic plants are in operation. Such wastes contain dangerously high levels of radiation. Furthermore, most of these waste products will retain their high radiation levels for thousands of years. This means that safe storage methods and places must be found. So far, no such guaranteed methods or places exist.

At the present time, the most feasible method is to store the wastes in such places as old salt mines. The problem here concerns underground water. Contamination of underground water systems by radiation from atomic wastes stored in old salt mines could easily occur, either now or at some future time. The human death toll could be high. The risk seems very great indeed since no one knows how radiation leak-proof the salt mines are now or may be in the future.

Although the current push toward the development of atomic breeder reactors may reduce some of the dangers and problems just mentioned, there is no way these dangers and problems can be completely avoided with atomic power plants.

A Solar future?

Solar energy farms sound great, don't they? And they can be! The next question is: "If they are so great, why hasn't someone thought of them - or better yet - built them before now?" It's a good question. The answer is not hard to find. The technology (especially for the filters) didn't exist until recently. Previous filters were not able to catch and hold the sun's radiant heat. Secondly, previous attempts to harness solar energy have always been misguided. They were directed toward small systems for individual homes, much like home furnaces, or toward meeting the needs of under-developed countries. Only a large-scale, mass-production, technically advanced approach will pay off in providing inexpensive electric power.

The second question is: "In the past, why haven't the utilities industry and the government provided the Meinels with the money, equipment, and men they require to build the solar energy farms?" This question requires a little longer answer.

To begin with, the utility companies were committed to waterpower, fossil fuel power, and to atomic power plants. They had placed their hopes on developing atomic plants that someday might be safe and clean. They were also counting on the discovery of an easy way to clean radiation from wastes, or the development of safe storage methods. This means the utilities industry was not terribly excited by the Meinel plan until quite recently, though small grants were awarded to the Meinels from time-to-time.

As the utilities industry goes, so goes the government. It has always been difficult for people with vision to get financing for large-scale ventures from the government without a certain amount of pressure from private industries or some other prestige source. Remember, it took a direct plea from Albert Einstein to President Roosevelt to get the government seriously interested in the development of the atomic bomb.

Lack of interest in the solar energy farms may now be a thing of the past. The adverse ecological effects and the other problems with conventional power sources detailed above have given utility executives and government officials pause for thought. They have begun to look for better energy sources

Solar energy farms promise to be one excellent alternate source.

As you read this article, plans are being made to build a demonstration solar farm. The demonstration farm is called "Project Western Sun" and is being financed by a large utility consortium. In addition, the Meinel's plan stirred positive reaction in Stockholm during the recent United Nations Conference on the Human Environment.

A solar energy farm could be a reality by 1982 (perhaps sooner), if the Meinels obtain $10 million in research, development, land acquisition, and construction funds. When you consider that one fairly small atomic breeder reactor plant is going to cost in excess of $500 million to design and build, the funds needed for the much more productive solar energy farm seem modest and reasonable.

The electricity produced by the solar farm should cost the consumer about the same as the projected future costs of electricity from other sources. If all environmental impact costs were considered, the cost of solar farm electricity might be lower then the true cost of electricity from other sources.

In the not-too-distant future, as the "harvest" of solar energy proceeds, the Meinels believe man will look upon the earth's natural deserts as one of God's greatest resource gifts. The imagination, foresight, planning, and perseverance of Aden and Marjorie Meinel may cause the sun to shine brightly on the future of electric energy.