Helicopter Delivers Solar Radio Transceiver

Used by the U.S. Cavalry in 1886 and vital to the Arizona Highway Patrol today...

Solar Powered Communications

Helicopters act as magic carpets to transport solar radio transceivers to remote areas where the cost of building roads or installing power poles and lines would be prohibitive. ROBERT HITCHCOCK In order to support vital mobile radio operations for Arizona Highway Patrolmen, an extensive communication network is maintained throughout Arizona. Base stations are placed strategically on mountain tops to provide long range radio coverage. While many mountain locations have commercial power available from an electric utility, some do not. The expense of running power lines to these remote radio sites is generally cost prohibitive and often not permissible under environmental rules on public administered lands.

SPIRT (Solar Powered Isolated Radio Transceiver) was designed to help in radio problem areas not supported by present radio sites run by commercial power of fossil fueled electric generators, and still remain within a limited budget.

The small SPIRT station can be transported by helicopter to any location on relatively short notice and be set up for full operation in one day. Once in operation the Highway Patrolman can communicate through the station to his nearest Department of Public Safety communications center. Saving of life and property in Arizona is often dependent on the speed with which these messages are sent.

SPIRT was designed and constructed by personnel of the Technical Communications Division in the Department of Public Safety, and the Arizona sun furnishes all the energy. A battery bank, which carries a reserve capacity of seven days, powers the radio during the dark hours and on overcast days.

Cost of using solar energy-powered radios, in this application, is minimal compared to running electric transmission lines or using fossil fueled generators. Electric transmission lines require a large initial investment. Small rotating electric generators are low in cost initially, but require frequent maintenance and regular fuel hauling and storage. On a ten year basis the solar power system will save fifty per cent or more of the cost of “conventional” power supplies for remote low power radio operation.

While the idea of solar powered radio relays is not original, application of solar power to a transportable, complete radio communication such as SPIRT is unique.

Funding to implement SPIRT was obtained from the Arizona State Justice Planning Agency with Federal Law Enforcement Assistance Administration funds.

Yuma is also putting solar energy to work in communications. At the Marine Corps Air Station, solar cell panels have been used since 1972 in equipment for the Air Combat Maneuvering Range. Remote installations which track aircraft are powered by panels costing about $7,000 each. Officials report that money saved in maintenance, travel, and fuel costs far exceeds the investment in solar equipment.

Another solar application is the Yuma Highway Emergency Notification System. The project is the first of its kind in the nation to combine solar-powered radio callboxes and standard telephones in an emergency highway communications system. The first 48 miles of Interstate Route-8 east of Yuma will be served by radio callboxes; the next 12 miles by regular telephones. The 75 miles of Arizona State Route 95 will combine radio callboxes and telephones along the entire route. Radio callboxes will be installed in pairs on opposite sides of I-8 so that motorists do not have to cross the interstate.

The caller pulls a handle opening the box, removes the receiver from the hook and talks directly to the dispatcher at the Sheriff's Office. There are no buttons or dials to confuse an excited or distraught caller. Before the caller even begins talking, the Sheriff's Office already has received the location of the caller and the callbox on the console display. The dispatcher determines the nature of the situation and type of help needed. All calls, including non-medical emergencies such as fire and rescue, are routed by the dispatcher to the correct response agency which sends a patrol car, tow trucks, ambulance or such other vehicles as are required.

It seems fitting that Arizona, site of a heliograph network during the Indian wars, is again using the sun to send messages across our state.

HELIOGRAPH LINES & STATIONS IN ARIZONA & NEW MEXICO

SOLAR SCIENCE from page 14

Stretched across the horizon in their original concept, using mirrors and special thin coatings to heat fluid in long tubes. These tubes then carried the heat to the boilers of conventional steam turbine generators.

In 1971 the Meinels formed Helio Associates and with backing from Tucson Gas & Electric, the Salt River Project, and Arizona Public Service, they built a pilot model of their solar collector at the University of Arizona. Experimentation prompted them to modify their ideas so that their concentrating mirrors wouldn't have to track the sun in order to be focused on the heating tube.

They now envision 300-foot diameter, sunken reflectors, looking much like gigantic swimmings pools, whose focus will always be on the heating element. Each of these giant mirrors would produce one megawatt (it takes more than 600 megawatts to power a city of 350,000). The powerplants could be operated on a solar-energy farm or located in the cities they are called on to power. A pilot model of the new mirror system should be ready for testing early next spring.

Another proposal by Helio Associates involves using abandoned Arizona mine pits as readymade collectors for solar power plants. An example is the Lavender Pit mine at Bisbee. As it and others are phased out of production, the suggestion is to convert them to solar powerplants. Studies indicate that a depression like the Lavender mine might produce from 80 to 100 megawatts of electricity, more than ample for the needs of Bisbee and Douglas. Solar reflectors would be placed on the terraced walls of the old pit to reflect large amounts of energy onto a boiler which would produce electricity.

William J. Kerwin, a professor of electrical electrical engineering at the UA, is developing a heavy-duty solar water heater for a manufacturer with an eye on the industrial market. This means getting surface temperatures of around 350 degrees Fahrenheit while the water passes through the heating unit, but Kerwin is confident that his special coating can do the job. Not only must it do the job, but the coating has to be capable of massproduction application. Already Kerwin says he thinks the problem can be solved with a special spraying technique. If the units that Kerwin and his colleague, Douglas Hamilton, come up with can keep a salt-saturated solution at 240 degrees Fahrenheit, the company may use them for yet another purpose: refrigeration units.

Minneapolis Honeywell has asked Marvin Martin, University of Arizona professor of mechanical engineering, Kerwin, and Hamilton to come up with a method of cutting the cost of certain heating processes in Honeywell's Phoenix computer plant. Right now they heat 40 big plating tanks electrically and the expense is enormous.

Meanwhile the National Aeronautics and Space Administration (NASA) has asked the prolific Kerwin and electrical engineering colleague Reginald Call to develop solar electric power cells capable of generating much more electricity than solar cells have been called on to produce in the past.

The task involves focusing a large mirror on a 212-foot array of the silicon wafers to produce the light of 100 suns. A single unit of this type would produce 3,000 watts, enough electricity to air-condition a moderate-sized house. While conventional solar cells produce power at the cost of $20 and more per watt, NASA hopes Kerwin's model will do the job for $2 per watt.

At the various facilities of the University's Environmental Research Laboratory near Tucson International Airport, one solar-heated structure is already operating and another will soon be built. The first house a modest 600 square feet uses a flat solar collector mounted on a sloping, south-facing roof. In operation for less than a year, the solar house held its temperatures to very comfortable levels throughout the winter, storing heat for cloudy days in a large water tank. A twostage evaporative cooling system is expected to keep things pleasant during the summer.

Soon a more advanced structure will be built using the revolutionary "venetian blind" solar collector for which laboratory director Carl Hodges and research specialist John Peck have filed for a patent. This device works by capturing heat when the blinds are turned to the dark side, reflecting heat when they are turned to the light side, and permitting a view in and out when turned horizontally. A subterranean bowl of rock will store cold air in the summer and hot air in the winter, thus avoiding some of the problems of water storage experienced in the older building.

Peck and a University of Arizona team headed by Professor Larry Medlin are designing the building. Medlin has already designed one residential solar-heated home for the Tucson area and plans more. A Tucson area builder has agreed to construct a residential home using the window-blind collector for solar heating, and the city of Tucson is proceeding with construction of a solar-heated fire station also using the same system.

One tremendously successful spin-off of research done at the Environmental Research Laboratory has been the widespread adoption of controlled environment greenhouses for vegetable production. In the 1960s the research lab, under the direction of Carl Hodges, had built a solar distillation plant in the fishing village of Puerto Penasco (Rocky Point) at the north end of the Gulf of California, producing 3,000 gallons of fresh water per day.

The researchers then coupled solar desalinization to greenhouses with inflated plastic roofs roofs that let in more sunlight than did conventional greenhouse roofs and with careful control of interior humidity got tremendously high yields. The Persian Gulf Sheikdom of Abu Dhabi, starved for fresh vegetables, liked the University of Arizona's new technology and had the Environmental Research Laboratory staff design and supervise construction of a massive 5-acre greenhouse complex. The tiny nation's diet is now supplemented by 700,000 pounds of fresh vegetables per year.

Using similar technology, but without desalting equipment, Superior Farm Products can ship out 20,000 pounds of cucumbers per day from their greenhouse plant in Tucson. Shrimp, too, may one day be a greenhouse-harvested crop, thanks to the ERL work. The Rocky Point facility now uses solar radiation to stimulate growth of algae that produce oxygen for the shrimp. Already one firm, impressed with the tremendous production capacities demonstrated by the project, says it wants to build a shrimp farm for commercial production.

The University of Arizona, a world leader in solar energy research and development, will be making valuable contributions to the state's efforts to have the Solar Energy Research Institute here. Dr. A. Richard Kassander, Vice President in Charge of Research, and long-time solar energy authority, has been appointed as a member of the Solar Energy Research Commission.

Kitt Peak National Observatory

Kitt Peak National Observatory the National Research Center devoted to ground-based optical astronomy in the Northern Hemisphere represents the world's largest concentration of facilities for stellar, solar, and planetary research. Located on a mountain 56 miles southwest of Tucson, Arizona, the National Observatory is the site of one of the world's most advanced stellar telescopes, the 158-inch Mayall Telescope, the nation's second largest.

The observatory also is the site of the world's largest solar telescope, the 60-inch McMath Solar Telescope, used for stellar and planetary studies as well as for solar research. The obser-

CORONA DEL SOL HIGH SCHOOL TEMPE, ARIZONA

vatory

TEMPE MUNICIPAL BUILDING TEMPE, ARIZONA

By inverting the traditional sun attracting character of perpendicular wall design, the resulting space volume, rotated 45 degrees, provides maximum sunlight in the sunken garden which surrounds the Tempe Municipal Building, and maximum shade upon the sloping walls, thus significantly reducing the air conditioning load.

A GLOSSARY OF SOLAR ENERGY TERMS

Solar energy people speak sun language much of the time. Here is a glossary of some of the most often used terms to help you understand what is being said.

ABSORPTANCE: The soaking up of heat in a solar collector. Measured as percent of total radiation available.

ABSORPTION REFRIGERATION: A cooling system operated by hot water (solar heated) instead of a mechanical compressor.

BEAD WALL: A simple but effective method of insulating glass walls. At night, Styrofoam beads are pumped into the air space between a double glass wall. During the day the beads are pumped out, allowing the sun's rays to enter and heat the house.

BIO FUELS: Renewable energy sources from living things. All forms of life, their byproducts, and wastes can be converted to organic fuels.

BIOCONVERSION: Conversion of solar energy to fuel by plants, algae, methane gas production, etc.

BRITISH THERMAL UNIT (BTU): The amount of energy required to heat one pound of water one degree Fahrenheit.

COLLECTOR TILT: The angle at which a solar heat collector is tilted to face the sun for better performance.

CONCENTRATOR: Reflector or lens designed to focus a large amount of sunshine into a small area, thus increasing the temperature.

CROOKES RADIOMETER: A glass sphere containing several black and white painted vanes which spin merrily in sunlight. It doesn't work exactly the way you might think, by the way.

EMITTANCE: The amount of heat radiated back from the solar collector. Measured as percent of energy absorbed by the collector.

ENERGY RANCH: Concept developed by University of Arizona scientists to fully use solar energy in agricultural applications. This includes heating, cooling, power generation, and bioconversion.

FLAT-PLATE COLLECTOR: A panel of metal or other suitable material that converts sunlight into heat. Usually a flat black color, the collector transfers its heat to circulating water or air.

FRESNEL LENS: A thin lens of glass or plastic so formed that it serves as a concentrator of sunlight. Often used in solar projects.

GLAUBER'S SALT: An inexpensive material used for storing solar heat. In melting, the salt soaks up a great quantity of heat which is later released for night-time heating or other use.

HELIOGRAPH: A signaling system that uses mirrors to reflect the sun's rays to a distant observer.

HELIOSTAT: A fixed mirror used to reflect the sun's rays into a solar collector or furnace.

INSOLATION: The amount of solar radiation received per unit or horizontal.

KILOWATT: One thousand watts of power; equal to about 11/3 horsepower.

LANGLEY: A unit of measurement of insolation. (One langley equals one gram-calorie per square centimeter.) The langley was named for American astronomer Samuel P. Langley.

MEGAWATT: One million watts, or one thousand kilowatts, about 1300 horsepower.

METHANE DIGESTER: Insulated, airtight container that speeds up the breakdown of organic wastes to produce methane gas, a useful biofuel.

PHOTOLYSIS: Chemical decomposition caused by radiation, including solar radiation. Solar energy can break down water into hydrogen and oxygen, for example.

PHOTOSYNTHESIS: The building up of chemical compounds with the help of radiation such as sunlight. Plants grow by photosynthesis; the sun helps produce all our food.

PHOTOVOLTAIC: Relating to electricity produced by the action of solar radiation on a solar cell.

PYRANOMETER: Another solar radiation measuring device.

PYROHELIOMETER: A very accurate instrument for measuring solar radiation.

ROCK STORAGE: A bin, basement, or other container filled with rock to act as a heat reservoir for a solar energy system. About 50 pounds of rock is needed for each square foot of solar collector on the roof.

SEA THERMAL ENERGY: A system that uses the stored heat in the surface water of the ocean to drive an engine. Frenchman Georges Claude demonstrated such a powerplant in the 1930s.

SELECTIVE SURFACE: A special coating applied to solar flatplate collectors. The selective surface absorbs most of the incoming solar energy and re-radiates very little of it.

SOLAR CELL (OR BATTERY): A device, usually made of silicon, that converts sunlight directly into energy.

SOLAR CONSTANT: The average amount of solar radiation reaching the earth's atmosphere per minute. This is just under 2 langleys, or 2 gram-calories per square centimeter.

SOLAR COOKER: Device such as reflector or oven for cooking with sun heat.

SOLAR DRYER: One simple one consists of two posts and a length of rope for drying clothes! But there are many other solar dryers, used for crops, air, etc.

SOLAR FURNACE: A device using mirror reflectors or lenses to produce very high temperatures at a focal point or "hot spot." Small backyard furnaces generate temperatures as high as 2000 degrees Fahrenheit; the largest solar furnace in the world reaches 5600 degrees F.

SOLAR POND: A power-generator using a pond to trap solar heat for use in running an engine. A small version of a sea thermal energy plant.

SOLAR POWER FARM: Large array of solar collectors providing heat to run a powerplant to generate electricity.

SOLAR PUMP: A device using solar energy to run a steam engine or electric motor to pump water. A few are available but in very small size.

SOLAR STILL: Equipment for desalting water by using the sun's heat.

SOLARIMETER: A simple solar radiation measuring instrument using solar cells.

SUN TRACKING: Following the sun with a solar collector to make it more effective.

THERMOSYPHON: The principle that makes water circulate automatically between a flat-plate collector and storage tank, gradually increasing its temperature.

TRICKLING WATER COLLECTOR: A solar collector pioneered by Dr. Harry Thomason of Washington, D.C. Water pumped to the top of a roof trickles down the valleys of black corrugated collectors and is heated.

"VENETIAN BLIND" COLLECTOR: A solar flat-plate collector invented by John Peck and Carl Hodges of the University of Arizona. A venetian blind is painted flat black on one side and placed between two panes of glass. When closed with the black side to the sun it collects heat which is transferred to air circulated between the glass panes.