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NOVEL NEW MACHINES for PULLING POWER from the SKIES

IN THE endless quest for cheap sources of energy, two proposals have recently been advanced which demand serious consideration, both for appeal to the imagination and the possibilities of practical operation.

The high speed windmill shown on this page is the latest development of Volf’s laboratories in New York. The first of these power producing units will be in operation by May first. Three fans are provided so that one is always facing a wind current. The fans are geared to a gyro stabilizer which runs on inertia so that the fans will not run down in calm intervals between gusts of wind.

A generator is driven by the geared shaft, producing current for storage batteries. In actual practice three or four small generators will probably be used, one or more of them being automatically cut out when wind velocity falls below a certain point.

Another idea, less close to realization than Volf’s windmill but involving natural phenomena just as dependable, partially owes its inception to the stratosphere balloon ascents of Prof. Auguste Piccard. The extremes of temperature encountered by Piccard, in which the outside air was around 75 degrees below zero while interior temperatures of the gondola were around 100 degrees, makes possible the operation of a thermal engine as described in detail on opposite page.

CHINESE WINDMILL WATERS FARM
Adapting an Oriental idea for raising water for his own needs and to irrigate his fields, a California farmer has constructed the curious apparatus shown in the accompanying photographs. Power from a windmill, transmitted through gears, revolves a spiral-shaped tube of pipe open at both ends. The outside end dips into a water-filled ditch at each revolution. Water is thus picked up, and runs by gravity around the spiral to the hub as the wheel revolves. An opening in the hub dis-charges the water into a trough four feet above the level in the ditch, giving a sufficient lift for the irrigation purposes desired.

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Giant Wind Turbines

Currents in Upper Air Form Unfailing Source of Power for “Windmills” of Future

WIND, at the surface of the earth, is proverbially uncertain; but recent researches show that, a thousand feet or more above the ground, wind is comparatively steady and unfailing. This has given new life to the hope of finding a substantial source of natural power, even more universally available than water power; and the designs illustrated here have been prepared by a German engineer, Honnef, the erector of several huge radio towers. As shown here, the structure carrying the power plant would be higher than any other building man has yet been able to erect.

The surveys which have been made in Germany show that, with little variation, wind velocities of 22 miles an hour are quite constant at the height illustrated. To utilize this most effectively, instead of small wheels, it is proposed to erect on each wind-turbine tower three power wheels, each 530 feet in diameter. The whole weight is so counterbalanced on bearings that it faces the wind; while the angle at which the wheels encounter the air currents is depending upon the velocity of the wind. If this is very high, as in a storm, they present their edges only; if the currents of air are light, the wheels take a vertical position, as illustrated in the detail at the lower right of our illustration. The wheel will begin to rotate in a breeze of but 4 miles an hour and, because of its great inertia, will turn steadily.

The method of generating the power is unique. Instead of gearing the great wheels to a generator, as in previous construction, each wheel is itself made the rotor of a great electrical generator. The rings are double; the armature and field coils are built into the outer and inner rings, respectively; and the output is fed into a distributing system, which has the necessary transformers and converters. The inventor plans 40,000-volt direct-current transmission lines. The cost of each 30,000-horsepower unit is estimated at $1,100,000; delivering 130,000,000 kilowatt hours a year with slight cost for maintenance.

The first experimental tower to be erected is to be 665 feet high, with 200-foot turbine wheels, and located near Berlin.

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Putting Nature’s Power to Work

Methods of Harnessing Natural Energy Described by DICK COLE

Upward of 40,000 inventions a year are granted patents by Uncle Sam, but not one of these offers a practical solution of the problem which scientists agree is the most pressing of them all— that is, how to harness natural sources of energy for power. Mr. Cole does not profess to have solved the problem, but the methods he describes here point out the trend of probable development.

WHAT is the most needed invention? Not television—not new kinds of airplanes—not speedier automobiles. Men of science are agreed that what the world needs most is a motor which converts the sun’s rays and other forms of natural energy into usable power. Orville Wright, Lee De Forest, Elihu Thomson, and other leading scientists are among those who proclaim the need for a new motor.

There are two sources of inexhaustible energy which at once occur to the inventor —wave or tidal power, and solar rays. A. Los Angeles inventor has developed a wave motor—an “inertia” motor, he calls it— which gives promise of being developed into a practical commercial project.

Scores of so-called “wave motors” have been built in the past, but none has proved a conspicuous success commercially. Usually the initial erection cost and the maintenance cost has been out of proportion to the results obtained. And, too, the force of a storm has been underestimated, and the first severe gale completely wrecks the machine.

The new “inertia motor” is absolutely storm-proof—in fact it could outride a tidal wave. And, too, it is the acme of simplicity —it requires no foundation, and has no connection with the ocean bottom except by its anchor chains.

A study of the accompanying diagrams makes it clear how the inertia motor operates. If you are mechanically minded, you will be impressed. The application of the name “inertia” will be obvious. When a wave starts to lift the hollow sphere, the massive weight inside, because of its inertia, resists the movement and exerts terrific pressure in the lower cylinder. Finally the inertia of the weight is overcome. Then it possesses momentum. When the sphere reaches the crest of a wave, the combined effort of the momentum and the recoil of the huge, semi-elliptic springs exerts an equal pressure in the upper cylinder. The tremendous pressure is applied to oil, which, in turn, operates a special turbine which runs a generator. The current is conducted to the shore by submarine cable.

The idea seems wholly practical. It is readily conceivable that a battery of “inertia motors” could be built into an elongated float set parallel with the wave movement, and power in unlimited quantities would be available.

The cost of building these motors would not be excessive—the maintenance cost is almost nil—the storm hazard is eliminated. Collision is the greatest hazard, but this is hardly worth considering as the float would have “running lights” at night.

A conservative estimate of the cost of the complete installation, except batteries, indicates that the value of the current generated, at 5c K.W. hour, would equal the installation cost in 18 months.

The power available from ocean waves is unbelievably huge. Suppose a wave comes along and lifts a 25,000-ton ocean liner 10 feet in 5 seconds. How much power is expended? The 25,000 tons is equivalent to 50,000,000 pounds; which, raised 10 feet, represents 500,000,000 foot pounds. Since this work is performed in 5 seconds, the amount done in one minute would be six billion foot pounds. One horsepower is that required to perform 33,000 foot pounds per minute, so simple division gives the wave’s horsepower as 181,818!

Every day in the year the sun is dissipating incalculable, immeasureable energy upon this earth of ours, energy which can be brought directly under control for immediate use, instead of waiting for a new geological era to make it available. The trapping and utilization of solar energy is not new—”solar engines” have been built before—but direct, commercial application of solar energy for power conversion has not been achieved.

An idea for a sun-power plant, illustrated in these pages, seems to be in a fair way to achieving success. A drawing shows the theoretical working of the solar power plant. One side of the unit is a tank containing water, heat insulated on all sides. On top of the tank is a shallow basin of greater area than the cross-section of the tank itself. This basin is covered with a layer of sheet copper providing a space of about one inch within the basin. Water from the tank enters the basin at the center point and spreads out to the rim where it is returned to the tank.

The top of the copper covering is painted flat black. Obviously when this tank is exposed to the glaring sun, the black surface absorbs the heat which is communicated to the water in the shallow basin. The entire mass of water is sealed from the atmosphere, and evaporation, which would tend to cool the water, is prevented. The thin layer of water becomes very hot and is carried into the main tank. The circulation goes on and on, constantly building up the temperature in the main tank. The heat insulation prevents radiation losses. In a working model, the temperature was built up to 180 degrees.

We have now established a mass of hot water. Now for the cold element. The tank at the right is the same volume and is insulated the same as the “hot” tank. In this case the water is circulated to an evaporation cooling system. This consists of a shallow upper tank from which are suspended many sheets of a special flax fabric such as desert water bags are made of. The water trickles down these. This cooling system will maintain the temperature of about 60 degrees in the cooling tank.

Apparatus Runs Automatically

We now have established a heat differential of nearly 100 degrees. The boiler and the condenser are an innovation. Note that each is set in the water of their respective tanks. The system is synonymous with placing a conventional boiler in a mass of molten lava. The boiler-condenser system is partly filled with pure, distilled water. The initial vacuum is established by injecting live, super-heated steam into the system. Then the cocks are closed, and when the steam condenses a permanent vacuum is established. Thereafter the boiler vaporizes a vast amount of water; the condenser liquefies the vapor; an injector pump returns the water to the boiler; an eternal cycle going on continuously, while between the two, a low pressure steam turbine converts the energy into terms of kilowatts.

Let us now transpose our theory into commercial terms. Southern California offers some ideal locations for a solar power-plant. Almost any point along its coast would meet the physical requirements, but Salton Sea, at the north end of Imperial Valley, is most ideal. Here the mid-day sun gives rise to temperatures of 110 to 120 degrees. And, too, the air is very dry which adds to the efficiency of the cooling system.

Construction Cost Moderate

The initial cost of erecting a power-plant like this would not be prohibitive. Even if it cost twice as much as a conventional steam plant of the same power output, this would be more than offset in several years by lower upkeep cost. The solar plant could be made so automatic in operation that it would require practically no attention.

Practically the only upkeep cost of this solar distillation plant is for fuel for a small gasoline motor which operates two pumps; one for pumping the distilled water to the storage tank, and the other for maintaining the salt water in the evaporation basin. A surplus of water must be provided to the evaporation basin to prevent crystallization, and, too, the basin must be thoroughly flushed out occasionally.

Still a third apparatus, deriving its power from running water rather than wave motion, has been built by an Arizona rancher. A main irrigation canal bordered his land, with a flow of 8 m.p.h. He constructed a raft with four 18-inch spiral rotors underneath, linked the driveshaft of each to a common shaft which drove a 32-volt generator. The motor functions with perfect satisfaction and supplies all the current consumed on the ranch. One of the accompanying drawings makes its construction clear. A similar machine can easily be constructed by anyone.

Electricity From Flowing Water

A momentum motor of this type has infinite possibilities. Imagine one with a battery of 20 spiral rotors 30 feet in diameter set in “the narrows” of the Bay of Fundy with its 60-ft. tides! Or in the St. Lawrence River or at Sault Ste. Marie! Or at numerous points in the Ohio, Missouri, Mississippi or Colorado Rivers! A momentum motor set in the Golden Gate at San Francisco without in any way impeding navigation, would develop enough power from the inflowing and outflowing tides to supply electricity to all the bay cities. As long as the tides ebb and flow, our supply of electricity will be assured.

On all sides we see examples of wasted energy—power! Think of what is wasted every day by the millions of automobiles and other moving vehicles. In an automobile, heat, the very essence of power, is wilfully wasted in enormous quantities—in the radiator and out through the exhaust pipes.

Waste Power of Automobiles

Suppose a coil of copper tubing were placed inside the exhaust manifold, and a highly volatile liquid, as ether or alcohol, were injected into this coil, wouldn’t the expanded vapor run a fairly sizeable “steam” engine? And couldn’t the vapor be condensed in a special radiator and be used over and over?

What about the energy wasted when the brakes are applied—dissipated in friction? Cruising along at 30 m.p.h.—”Stop” sign— on with the brakes. Twenty to fifty horsepower gone beyond recall.

Suppose instead of friction brakes, electrical brakes were used, and the current generated were stored in batteries, how much wasted energy could be saved?

Of course, with fuel at a reasonable price, it is not practical to make the elaborate installations necessary for conserving the wasted energy. We have one outstanding example of its being done. On the electrical section of the Chicago, Milwaukee & St. Paul railroad, when a train goes down the long grade over the Cascade mountains, the motors are converted into generators and serve as electric brakes, and at the same time push considerable current back into the line, which is utilized by another train coming up the grade. Trains are scheduled to take advantage of the electrical counterbalance.

Heat Represents Power

Heat is usually associated with all motors and engines. Somewhere in the scheme of things heat has played a part. But the generally accepted idea is that abnormal heat is required, as in the steam engine and internal combustion motor. The fact of the matter is that potential power exists wherever two masses of different temperature are available. Dr. Georges Claude demonstrated this with his remarkable vacuum, or low pressure steam turbine, down on the coast of Cuba, described in a past issue of Modern Mechanics and Inventions.

Much has been written about atomic power, the tremendous energies compacted within the atom being depicted as capable of furnishing all the power the world will ever need for billions of years. This is undoubtedly true, but scientists are by no means sanguine that a method of applying the atom’s power will ever be devised.

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New Schemes for Harnessing the Winds

INVENTORS PROPOSE STRANGE PLANS TO BRING THE OLD DUTCH MILL UP TO DATE

IS THE windmill coming back? With strange, unconventional types, inventors are seeking to adapt it to a modern age. Their experiments may bring new success in man’s effort for 800 years or more to harness the wind for power.

Centuries ago, people milled their flour, sawed wood, and pumped water with the picturesque European windmills whose enormous “sails” swept from earth to sky. This country contributed the smaller and more practical narrow-bladed type that pumps water on farms today. A new miniature design shaped like an airplane propeller charges storage batteries for radios and for lighting rural homes.

To provide power on a larger scale, giant structures envisioned by modern designers would reach heights where winds constantly blow. One inventor, Hermann Honnef, proposes to mount 500-foot wheels, with spokes that serve as vanes, upon high towers. A single “skyscraper windmill” of this type, he estimates, would generate enough electricity for a city of 100,000 inhabitants. Another designer, Peter Bendmann, offers plans for a pair of giant windmills, connected at right angles to each other and arranged to move around an endless track so as to obtain maximum power in wind from any direction.

At Burlington, N. J., recently, a spool-shaped rotor ninety feet high strained at its moorings with a ten-ton horizontal pull, when an electric motor spun it in the wind. The inventor, Julius D. Madaras, plans to mount twenty such rotors on flat cars, and make the wind propel the whole train around a circular track. Dynamos geared to the car wheels would generate many times the amount of power needed to turn the rotors, and the surplus would be marketed.

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Super-Windmills

Plans are being made to harness mankind’s oldest and cheapest source of power for industry by means of huge aerogenerators.

By Frank Tinsley

THE next few years may see a decided change in the landscape of our country. In certain strategic places which promise a constant, strong wind such as mountain passes, will grow strange structures resembling the Martian machines of H. G. Wells. But these will be instruments of construction, rather than destruction —tall, steel towers supporting fans to convert wind energy into electrical power.

Members of the Congressional Interior and Insular Affairs Committee are enthusiastic over a new proposal to erect these machines. Introduced by Representative John R. Murdock, D.,Ariz., chairman of the committee, a bill drawn up by the Department of the Interior and endorsed by the Federal Power Commission authorizes a $2,750,000 government project to build a test aerogenerator.

In 1941, a full-scale instrument was built on a mountain top in Vermont and hooked up to the high tension system of the Central Vermont Public Service Corporation as an auxiliary power source. Mounted on a 110-foot tower, its twin 56-foot blades were designed to develop 1,200 kilowatts at a wind velocity of 30 mph. Under favorable conditions, it actually developed 1,400. Although a practical success, structural and financial difficulties ended the experiment.

The newly proposed design is the product of years of research by Percy H. Thomas, well-known power plant engineer formerly of the Federal Power Commission. Towering 475 feet above the ground and equipped with a pair of three-bladed impellers, it operates automatically in a wind as light as 10 mph. At its maximum required velocity of 28 mph it delivers 7,500 kilowatts. During dangerously high winds the impeller blades can be feathered and braked to a halt and the structure is stressed to withstand hurricane velocities up to 200 mph. The plant is completely self contained with a central generator, converter, transformer, etc., mounted in a rotating housing atop the tower. The energy developed by the 150-foot diameter impellers is transmitted to the generator through geared-up shafting. All parts of the plant are accessible for inspection and repair.

The techniques of modern airplane construction suggest the possibility of further development of this design. (See illustration.) The use of light metals would lighten loads and relieve stresses. A central tubular elevator shaft would strengthen the structure, provide easier access to the operating head in foul weather and act as a protected duct for the power lines. The addition of a third impeller unit would increase the power outlet by 50 per cent while increasing the overall weight of the rotating head by but 25 per cent. Mounting small, individual generators in each impeller nacelle not only balances the weight of the wheel but also eliminates weighty, vibration-producing shaft transmissions. Instead, simple power lines are led through the pylons and elevator shaft to the ground where the heavy elements of the plant are installed in a substantial building. This placement of the generators, converters, etc., materially lightens the tower structure.

Dependent on the ever-changing wind, a single aerogenerator obviously can not be relied upon for continuous or “firm” power. However, interconnected but scattered units can maintain a firm average output. Tests indicate that wind velocities in given locations remain constant for 22 out of the 24 hours. This can be enhanced further by placing the aerogenerator groups in mountain passes where converging ranges funnel the wind flow in a strong, steady venturi effect. Such groups, acting as a free-fuel auxiliary to established steam or hydroelectric systems, may supply up to 40 per cent of the total utility power. During slack periods of consumption, this aero energy can pump used water back into reservoirs, thus storing power for future use. This means that during droughts, scarce water can be used to develop power over and over again.

As compared with complicated steam power plants and the vast sums spent on hydroelectric dams and reservoirs, the first cost of the aerogenerator is modest. Even this would be considerably reduced by the limited mass production necessary to produce a moderate number of aerogenerator complexes. Once installed, operation costs are extremely low.

European experts, working under the Marshall plan, have launched a research program to speed the harnessing of the wind for electricity. England is said to be three years ahead of us in development Recently a German engineer entered the field with a proposal to build 1,000-foot wind towers to provide power for the industrialization of Schleswig-Holtein.

Russia led the world in aerogeneration development during the 1930′s but like most other Red scientific projects its postwar status is veiled by the Iron Curtain. In her desperate effort at industrialization, she may seize the lead again. Meanwhile, with Congress now alerted to the opportunity, we can hope that America is awakening to the possibilities of this great, free source of untapped power.

Mounting a 98-foot wheel atop a steel tower 82 feet high, Soviet Engineers have successfully operated a 100-kilowatt wind-electric plant in the Crimean sector for more than a year. The windwheel has self-regulating variable-pitch blades which are automatically operated by centrifugal force. The Entire machine rotates on a spherical pivot in the top of the tower. The device is kept into the wind by a small motor actuate by a weather vane.