Emerging Oil Prices making Renewable Energy More Powerful

"Emerging fossil fuel prices are making renewable energy more involving in the global market"

Renewable energy can't offer much relief to drivers and companies seeing their profits evaporate because of skyrocketing oil prices, because viable green alternatives to gasoline are hard to find. Biofuels such as ethanol and biodiesel aren't widely available, and hydrogen-powered cars aren't expected to hit the market for years.

Price curves
But in the electricity market, green power, especially wind, is already competing with traditional sources. At today's average wholesale prices, wind costs 4.2 cents per kilowatt hour, compared with 4 cents for coal, 6.8 cents for natural gas, 9.1 cents for oil and 10 cents for nuclear power, according to Kyle Datta, managing director at the Rocky Mountain Institute, a research group focused on eco-friendly business.

Experts estimate that at today's consumption rates, known global supplies of oil and natural gas would be depleted within decades. But prices are expected to rise significantly long before supplies run out, making those fuels too expensive to use at current levels.

"They're never going to run out, but the ability to match supply to demand may already have run out, especially for oil," said Stephen Leeb, president of Leeb Capital Management and co-author of "The Oil Factor," which predicts that oil could hit $100 a barrel by 2010.

In the short term, fossil fuel prices are being driven up by war, political instability, natural disasters and other variables. The long-term outlook is clearer — global supplies are dwindling as demand soars, particularly in China and India, where automobiles are multiplying and economies are growing a breakneck speed.

"We should treat the prices as a warning that we need to act to promote energy efficiency and renewable energy," said Ralph Cavanagh, an energy expert at the Natural Resources Defense Council. "They represent a terrible threat to the vitality of the United States."

Meanwhile, improving technology, tax credits, low interest rates and government mandates are making renewables more widely available, establishing an inexhaustible energy supply that will keep driving prices down.

Different Kinds of Renewable Energy

• Solar energy which comes from the sun can be turned as electricity and heat. Solar panels on the roofs of houses, building and other establishment are use to store the solar energy. The sun's energy harnessed by the panels runs generators which provide electricity. There are stand-alone solar panels that you can put in your yard to save the sun's energy in a generator.
• Geothermal energy is an energy that comes from the heat inside the earth. It's simple technology that involves boring a hole into the ground to take the heat from the earth's crust. The heat that comes off is used to heat water and make steam to power generators to make electricity.
• Biomass energy is from the plant and trees. This energy alternative makes use of husks that come off rice after it is harvested and the waste from the corn. This "biomass" can be burned in a power station built for such a purpose. It emits less pollution than if the waste was left to rot, because it would produce a lot of methane.

Sources: Wood (most common source), plants, agricultural waste, industrial waste, even methane gas from community landfills.

Uses: fuel for transportation or to manufacture product that would otherwise use fossil fuels.

• Water Energy - the natural evaporation/precipitation cycle makes water a renewable source of energy. The heat of the sun causes water in lakes and ocean to evaporate and form clouds. The water then falls back to earth as rain or snow, and goes to the rivers and streams that flow back to the ocean. Moving water can be used to power water wheels that drive mechanical processes. Water Wheels are useful for generating mechanical energy to grind grain or saw wood, but are not practical for generating electricity because it is bulky and slow. Water energy emits about 30 times less greenhouse gas than modern natural gas power plants and 60 times less than coal-fired plant, which makes it a clean source of energy.
• Wind Energy is captured by wind turbines and used to generate electricity. The costs of wind energy are going down as mass manufacture of turbines becomes more accepted. It costs the same as setting up a new coal or nuclear power station. More importantly, external cost to health care and the effects of acid rain are 50times less than when using coal.

Renewable Energy - Benefits

The most obvious benefits of renewable energy are that it is far less polluting than conventional energy and will not run out. Renewable energy can also be produced more locally. This means that it can help local and national economies by using local resources and creating jobs. It will also help reduce the country’s dependence on overseas countries that may be politically unstable. This will help ensure supply and avoid price fluctuation.

Renewable energy is also much safer than nuclear energy which some people regard as ‘clean’. Accidents in nuclear plants can be catastrophic and there is the added problem of having to deal with nuclear waste.

One of the most important benefits of renewable energy is the fact that it’s non-polluting. And of course as the name tells us it is renewable and does not use resources that can never be replaced. Renewable energy has a much lower environmental impact than conventional sources of energy. But there are other advantages to using renewable sources of energy.

There are many benefits of renewable energy to the ordinary citizen and business owner. Homeowners will reap rewards from using renewable energy and energy-efficient appliances by saving money in the long run and reducing environmental impacts. It also renders us able to fuel our homes independently in many cases. Using renewable fuels makes us less dependent.

Benefits of Renewable Energy Source:

* Renewable energy sources offer clean alternative to fossil fuels.
* RE produces little or no pollution or greenhouse gases.
* RE will never run out

Our Future Energy - Solar

Great video.. Wow! I didn't know that burning fossil fuels produced pollution!

The lost history of biofuels

It's surprising that the history of something as important as renewable energy in general, and biofuels in particular, would be so little known. If you read current historical works on energy, there is no mention of ethanol or other biofuels. The Prize or most other histories of the energy have little or no mention of alternatives.

Its like we have a history of Rock and Roll with the Beatles but not the Stones. Or of aviation with the Wrights but not Curtis. Or of dance with Fred but without Ginger.

Before we open a narrative on the history of renewable energy and biofuels and the people who fought for their recognition, we might take a minute to think about history itself.

Thucydides (460 - 400 BC) once said: "The way that most men deal with traditions, even traditions of their own country, is to receive them all alike as they are delivered, without applying any critical test whatever..."

Plenthy of material

To ignore alcohol as a fuel entirely in the history of energy certainly seems fishy. There is plenty of raw material to go on. For example:

• At least 152 popular and scholarly articles under the heading "Alcohol as a Fuel" can be found the the Readers Guide to Periodical Literature between 1900 and 1921.
• About 20 references to papers and books written before 1925 are found in the Library of Congress database catalog; a 1933 Chemical Foundation report lists 52 references before 1925 on alcohol fuels. A1944 Senate report lists 24 USDA publications on alcohol fuels before 1920. Technical books from the period document hundreds of additional references .
• The New York Times database returns 408 results for alcohol and fuel in the 1900 to 1925 time period and 602 in the next 25 years. In the 1951-1975 period the number drops off to 268. But the last quarter of the 20th century, 645 articles are found.

Why? We could chalk it up to several things, including these:

Roads not taken. Historians love to tell stories about success and heroism. Writing about "failures" -- even failures that may later prove useful -- is rarely done.

Women's history. Many of the people who were most vocal on issues like air pollution and the need to put public health ahead of corporate profit were ignored by traditional historians precisely because of their gender.

Industrial history. Historians who have written histories of businesses or of great enterprises are often the recipients of generous grants and cooperation from the industries about which they are writing.

Why its important now

We are only about two centuries into the industrial revolution, we often forget that renewable energy was the only energy source for most of human history.

We can appreciate the history of renewable energy as part of our "useable past." There are lessons here about roads not taken. In terms of social context, we need to understand the history of renewable energy as part of our tradition of reform.

Most importantly, renewable systems are flexible and rapidly scalable. Massive outputs of ethanol or butanol or other biofuels, in the range of billions of gallons, could be scaled up within a matter of months or a few short years. Coal and petroleum bases systems take much longer to build, as we learned in World War II.

Renewable energy sources tend to be more expensive, it's true.

Unlike fossil energy from coal or oil, or nuclear energy from uranium, renewable energy is dispersed, decentralized and more difficult to collect and concentrate.

Solar, wind and hydro power have no fuel costs, but have much higher capital costs that have to be covered initially. Fossil energy, on the other hand, has been economically more attractive even when renewables cost the same because fossil energy fuel costs are spread out over the life of the power generating plant.

Traditional economics have put renewables at a disadvantage for other reasons as well:

External environmental costs of fossil fuels and nuclear power have been imposed on populations, especially weaker segments

The costs of resource extraction from politically unstable foreign lands have been placed on taxpayers through bloated military establishments.

And so the true cost of oil, by one estimate, is between $5.60 and $15.14 a gallon.

Another cost is political. For instance, America's oil habit certainly helped turn U.S. citizens into targets of choice (Washington Post, 2001)

US government policy signals about energy have been unrealistic and totally unreliable.

But the question is, really: Can renewable technology ever be cheap enough, and provide enough power, to avert catastrophe?

Learning the lessons of the past as a guide to the future, as Thucydides said, is the point of studying history

NEXT: Renewable energy history categories

Solar Power - Developments in Renewable-Energy Technology

Photovoltaic, or solar-electric, systems capture light energy from the sun's rays and convert it into electricity. Today these solar units power everything from small homes to large office buildings.

Technological improvements have made solar-electric modules more cost-effective. In the 1980s the average price of energy captured with photovoltaics was 95 U.S. cents per kilowatt-hour. Today that price has dropped to around 20 cents per kilowatt-hour, according to Collins, of the American Solar Energy Society.

The cheaper rate is still more expensive than the average national price of electricity, which in 2003 was a little over 8 cents per kilowatt-hour, according to the U.S. Department of Energy's Annual Energy Review.

Other recent advances include "thin film" photovoltaic technology, a high-tech coating that converts any surface covered with the film into a solar-electric power source.

Capturing and Storing Energy From the Sun

Current interest in solar energy is not the first time people have been excited about its potential. Reportedly, the first flat-plate collector appeared in 1774. It consisted of a wooden box with three layers of glass that heated air to 140° F. By the turn of this century, development had progressed to the point that efficiencies were about as good as they are today.

Other sources of energy were more economical and convenient to use, so there was little incentive to put solar energy to work. But the finite supply of fossil fuels is now recognized, and we must prepare for the time when their cost may be much higher. An added benefit of solar energy would be reduced pollution, which will become more important as population increases.

The first consideration for any application is to reduce the energy requirement to the point where the economics of using solar collecting equipment is more favorable than investing in energy conservation measures. Most homes were constructed when fuel was plentiful and extremely cheap, so investment in solar heating and cooling should be thought about only after adequate weatherization.

The real cost of energy delivered from solar systems may range from the equivalent of $1 up to $10 per gallon of propane. At these levels, many energy conserving improvements will be economical. There is another payoff for weatherizing homes: they will be more comfortable because cold drafty conditions are reduced.

Equipment Can Prove Expensive

Energy from the sun is free, but equipment for collection, storage, and use can be expensive. A number of factors are involved in determining how much can be invested for a solar collecting system but the first cost of the equipment and the amount of energy that can be effectively used during its practical life are most important. The energy that can be used is determined by the solar energy available, ability of the collector to deliver energy, and whether that energy can be put to work or stored at the time it is collected.

An application such as water heating requires energy on a regular basis throughout most of the year, so more money can be invested in reliable, efficient hardware. Grain drying requires very large amounts of low-quality energy during a short period of time, so the system must be inexpensive or used for other applications during the rest of the year.

Investing in a solar collector depends to a great extent on tax credits granted by a State. With limitations, the Federal income tax credit of 25 percent plus the State tax credit in some States will now pay for up to 55 to 75 percent of the investment in solar equipment — which makes many solar systems economical.

Solar energy collecting systems often are classified as either active or passive. In active systems a fan or pump moves the working fluid or air through the collector. The fan or pump is turned on or off depending on whether the working fluid temperature is high enough to provide heat for storage or a process.

In passive systems the working fluid moves because of difference in density (hot air or hot water moves up and cold air or cold water moves down) or where the energy is moved by radiation or conduction heat transfer. Passive systems sometimes are defined as those where only a small amount of energy from fossil origin is used for moving the collected energy, for example one unit from fossil origin to 50 units derived from solar.

A system that combines both active and passive features is sometimes called a hybrid system and some authors classify this as a third type.

Photovoltaic collectors convert sunlight into direct current electrical energy but that method of energy collection is very expensive and used only for special purposes such as providing a small amount of energy for remote communications equipment and powering space vehicles. Therefore, this discussion is limited to applications where the function is to convert solar energy into heat energy.

Active Systems

Focusing collectors and flat-plate collectors are used for heating applications. Focusing collectors have a large area for entry of solar radiation that is then reflected onto a receiver. The entry area must be positioned so it sees the sun. This requires some type of mechanism to move the collector assembly during the day, which increases the cost of the collector.

High temperatures can be attained by focusing collectors. But most applications for heat in residences and farm service buildings can make use of energy gathered with flat-plate collectors.

Many different types of flat-plate collectors are being used or under development for putting solar energy to work in homes, farm service buildings, and agricultural processes. They range from simple systems costing very little to incorporate in the design of a new building, to more expensive equipment where cost is so high that the system would be economical only if conventional energy expenses increase.

Examples of inexpensive, simple systems are transparent roofs on farm service buildings for heating air to dry grain, or south-facing windows on residences that allow solar energy to be trapped inside. Complete systems for heating water may have an installed cost of $50 or more per square foot of collecting area.

Active systems are generally regarded as more complicated than passive systems, but a process such as grain drying can use a simple collector and maybe only one thermostat. Besides, passive systems can become complicated when controls and equipment are used to restrict natural air movement or when movable insulation is incorporated into the design. The prospective user should keep in mind that it is best to use as simple a system as possible that will provide heat for the user's needs.

Flat-plate collectors may be designed for operating only a few degrees above the outside temperature for uses such as grain drying. Those required to provide heat to a residence during winter may be designed for operating at a temperature differential of 100° F or more. Generally, cost of a flat-plate collector rises as the operating temperature differential increases.

The typical active system consists of a collector assembly, an energy storage unit, a control system, and two energy transport systems — one between the collector and storage and another between the storage and the process requiring heat.

Some vendors provide complete systems while others offer components that can be used to make up a complete system. Choosing between them depends on the type of process involved and abilities of the individual or contractor installing the system. Competent assistance should be found When planning a components system, because each component must be sized correctly to work with other parts of the system.

Backup System Needed

A backup heating system is needed because there are cloudy periods when solar energy cannot provide the necessary heat. The control system is quite important because it must be able to sense when heat can be added to storage, removed from storage, or when the backup furnace is required.

All these functions must work automatically because the typical user will not be present or may not be inclined to provide the manual controls needed to make the system work effectively.

The flat-plate collector for an active system consists of one or more of the following: 1) An absorber plate 2) A transparent cover or covers 3) Insulation behind the absorber plate 4) A box to contain the parts 5) An inlet and outlet to let the working fluid pass. The working fluid can be either liquid or air.

The bare-plate collector is used where low temperature differentials are adequate. Adding a transparent cover above the absorber allows a higher temperature to be maintained because heat loss from the absorber is reduced. A second transparent cover can be added to obtain even higher temperatures.

The absorber plate is generally made of sheet metal, or a flat surface of other material, and painted black to absorb the sun's rays. Flat black paint used for absorbers in high temperature collectors should be capable of operating at temperatures to 300° F, and possibly higher, without damage.

The absorber plate must serve to transfer absorbed solar heat to the working fluid. Fins protruding into the air may be added to the absorber, giving more surface area to transfer heat. With the liquid-type collector, the distance between liquid tubes determines how well heat can be transferred.

The weight of material in an absorber plate influences the time it takes to heat up before the working fluid can be circulated. Heavy plates require more time to heat up than light plates. During intermittent cloudiness, the plate might not heat up before a cloud cuts off solar energy. Then the heated plate would cool down while waiting for another period of sunshine.

Insulation Important

An exposed hot surface quickly loses heat, so the back side of the absorber must be insulated. Insulation between the absorber and the back of the collector box should be stable at high temperatures. Some insulations have organic materials in them that break down at high temperatures.

Vapor may deposit particulate matter on the inside of the transparent cover. This could make the collector useless until a new transparent cover is installed.

Features to reduce heat loss from the sides and ends of the collector should be incorporated into the box for the absorber plate. Collector boxes need to be sealed to exclude water, and strong enough to resist the loads imposed on them by wind and snow. Pipes or ducts entering or leaving the collector box should be insulated to reduce heat loss.

Glass has been commonly used as a transparent cover for collectors, but some plastics have desirable characteristics. Low-iron and plate glass are recommended because they absorb less solar energy than ordinary glass. The glass surface can be treated to reduce reflection, increasing transmitted energy.

Plastics are being used in many applications because construction of frames is not so critical and most plastics are somewhat less expensive than glass. Plastics resist impact stresses better than glass and generally transmit as much or more solar radiation. However, plastics generally allow more thermal energy loss than glass.

Care should be taken in selection to get plastic resistant to ultraviolet rays in sunlight and to the high temperatures encountered. The plastic should not retain a static charge which would attract dust.

Fans or pumps for moving the working fluid between the collector and storage need to be capable of long term, efficient operation. Ducts and pipes should be sealed and insulated; the amount of insulation recommended depends on the temperature difference between the working fluid and the surrounding air. Liquid leaks in pipes can be easy to spot, but air leaks in ducts present a problem because they aren't easily detected.

The control system needs to make decisions for operation of components and to be as simple as possible but still adequate to control all the aspects of operation. Where possible, users should understand the system so as to recognize when service is required or make their own adjustments and repairs.

Passive Systems

Passive solar systems are generally simple and low in cost for the quantity of heat added. Most are operated with a minimum of controls designed into the system, but may require manual adjustment.

Careful design may be required to obtain reasonably stable temperatures in the environmental space. Overheating or very cool conditions can result if the right combination of glazing and storage are not provided.

The four main types of passive solar systems are direct gain, thermal storage wall, attached sun space, and convective loop.

The direct gain system uses south-facing transparent walls, or windows, that allow solar radiation to enter directly into the environmental space that is to be heated. A part of the solar radiation is absorbed by the floor and a part reflected onto the walls and ceiling where it is absorbed.

The absorbed radiation is converted to thermal energy (heat). Some of it goes to heat up the storage material and some is lost by convection to the air which comes in contact with the floor and walls.

Movable insulation to reduce heat loss through the transparent cover at night increases overall thermal performance of this system.

The direct gain system is effective for south-facing surfaces because of the sun's low position in the sky during winter months. In summer when the sun is at a higher position in the sky, the glazed area can be shaded by overhang on the structure, awnings, or deciduous trees.

Advantages of the direct gain system are that it is one of the least expensive, simplest solar systems and can function without constructing a storage component in cases where the floor or wall can be used.

Disadvantages are degradation of fabrics and other materials in the room by ultraviolet radiation in the sunlight, temperature swings in the room which can be quite high unless thermal storage is carefully designed, the need for movable insulation to reduce heat loss through the glazing at night, and too much glare which can occur in the room during the day.

Thermal Siphon

The convective loop system has an absorbing surface placed behind the transparent cover on the south wall. This surface converts the sun's rays to heat energy that heats up the air and causes a thermal siphon effect. Cool air from the room flows up past the absorber where it is heated, and then exhausts near the ceiling. A small collector can be effective at heating a room during daytime, but there is limited storage and the room will cool off quickly at night.

Air movement caused by the thermosiphon would not be very effective at adding heat to massive walls inside the room. Thus one must be careful not to have too large a collector. At night, reverse thermal circulation can occur since the cold glass near the absorber cools it and will cause cool air to exist in the space between them which sets up a reverse circulation process. This should be prevented by closing off the loop at night.

Advantages of the convective loop system are that glare and ultraviolet degradation of fabrics are not problems, it is relatively inexpensive, it can be readily added to existing buildings, and night heat losses can be lower for other types of passive design. Disadvantages are that careful engineering and construction are required to insure proper airflow, prevent overheating, and assure adequate thermal isolation at night.

The thermal storage wall typically is a masonry wall with the south-facing side painted black to absorb solar radiation. The wall has one or two transparent covers. During the day, the south face of the wall is heated and starts the process of conducting heat through the wall. A so-called temperature wave moves through the concrete, causing the inside surface to be the wannest a few hours after sundown.

With thermal storage walls, glare and ultraviolet degradation of fabrics is not a problem, the temperature swing in adjacent living space is much lower, and designs are becoming available for allowing the proper sizing of units for homes. Disadvantages are the increased cost of constructing the wall, the space it occupies, and the amount of heat lost to the outside at night unless movable insulation is used.

Greenhouses, or similar structures called attached sunspaces, can be attached to new or existing buildings. The greenhouse is heated during the day and this warm air can be added to adjacent living space to reduce heat requirements.

A massive thermal storage wall can be used to absorb some of the solar radiation directly and transmit it to the adjacent living space and greenhouse during nighttime hours. The wall can reduce the amount of overheating that occurs in the greenhouse during daytime.

The sunspace acts as a buffer zone to reduce heat loss at night from the building to the outdoors. Advantages of the attached sunspace are that it provides smaller temperature swings in adjacent living space, reduces heat loss from adjacent living space to the outside, and is readily adaptable to existing buildings. Disadvantages are that thermal performance varies greatly from one design to another, making performance difficult to predict, and cost can be quite high if commercial buildings are used.

Storage Systems

Solar energy is received during the day and some type of storage system is required to allow that heat to be available at night. The two basic mechanisms for storing energy are to use sensible heat capacity of materials and to use the latent heat of fusion (heat given up during a change in phase from liquid to solid states).

Sensible heat capacity of a material is the amount of energy it takes to heat a unit of material. For example, it takes 1 British thermal unit (Btu) of energy to increase the temperature of 1 pound of water by 1° F. It takes about 5 pounds of rocks or concrete to store as much energy as 1 pound of water.

Even though water has the highest sensible heat storage capacity, rocks and concrete have advantages in applications such as air-type collectors and passive solar applications. Data in the table show the quantity of rocks or water required to store 500.000 Btu's of energy. This amount of energy would be equivalent to the heat produced by burning 7 to 8 gallons of propane.

Thermal energy storage properties and requirements to store 500,000 Btu's with a 30° F change in temperature.
	Rocks	Water	Phase-change material
Specific heat capacity, Btu per lb per degree F	0.2	1.0	0.5 (ave.)
Heat of fushion, Btu's per lb	-	-	100 (ave.)
Density. lbs per cu ft	90	62	100
Storage of 500,000 Btu's
Weight, lbs	88,500	16,670	4,350
Volume, cu ft	930	2701	552
12,000 gallons.
2An additional 25% for passage of air is added to volume.

Density of a material is the weight of that material that can be put in a box which is 1 foot in all three dimensions.

Multiplying the specific heat capacity by the density gives the volumetric heat capacity of a material. The volumetric heat capacity of water would be 62 while that for rocks would be 18 Btu's per cubic foot per degree Fahrenheit of temperature change. Thus water has a volumetric heat capacity over three times as great as for rocks.

Materials that change from liquid to solid at a temperature of around 90° F are being developed for the phase-change process, because large quantities of energy can be stored in a relatively small space. When water changes from liquid to solid (forms ice), 144 Btu's per pound of heat (the latent heat for fusion) are given up. Obviously, water cannot be used as a phase-change material in solar heating applications because 32° F is much too low to provide comfort.

Glauber's salt — sodium sulfate decahydrate — melts and freezes at 90° F and is one material being used for phase-change storages.

Considerable work is being done on these phase-change materials because large quantities of heat can be stored in a small space.

Phase-change material properties shown in the table are characteristic of those being used or considered for applications with solar systems. It takes four times the weight and five times the volume for water to store the same quantity of heat as this typical phase-change material. That has obvious advantages for retrofit applications because much less space is required to provide heat storage.

Rocks, Water Are Common Materials

Most energy storage systems that have been installed to date use the specific heat capacity of materials for storage. Rocks and water are both common materials and storage structures can be purchased or easily built.

An insulated steel tank is commonly used for liquid storage systems. Underground concrete tanks have been used for some larger systems, and fiber glass tanks for a number of smaller ones. Materials used to construct the tanks should be compatible with any chemical treatment the water requires.

Designs of a storage tank for water should allow for temperature stratification in the tank. This means hot water can be added to or removed from the top of the tank, and cold water can be added or removed from the bottom.

The void space between rocks in a storage allows passage of air. The rocks must be small enough so there is adequate surface area to allow heat transfer from the working fluid, air, to the rocks but large enough so the passageways allow easy movement of the working fluid. Rocks with an average diameter of 1 to 2 inches are usually recommended.

Rocks and packaged, phase-change materials are commonly used for air-type collectors. Packages for phase-change materials must be designed so there is adequate surface area for transfer of energy into or out of the unit.

All heat storage units — liquid, solid, or phase-change — must be insulated whether in the building, outside, or underground.

Reflectors

Reflecting surfaces can be positioned so they increase the amount of solar energy arriving at a collector. The correct position for a reflector depends on orientation of the collector and the season of the year during which it will be used. No general rule of thumb can be used to estimate the increase in collected energy because the changing position of the sun with the seasons affects the direction where solar energy is reflected.

The increase in collected solar energy per dollar invested in a reflector should be greater than from additional investment in collectors.

A computer simulation has been used to predict the increase in energy collected by a south-wall solar collector installed on a farrowing house in Kansas. A white-painted reflector in front of the collector and extending out as far as the collector is high (8 feet) increases collected solar energy by 15 to 16 percent. However, not all the reflected energy can be effectively used during spring and fall, so the net increase is only about 12 percent. Experimental testing has shown the computer simulation approximately correct for this Kansas location.

Information Sources

The prospective user should spend some time learning about solar energy technology. Another method is to enlist a good consultant, but the number of experienced technical personnel is limited and most are quite busy.

Sources for further study are textbooks and publications from State and Federal agencies, industrial associations, and companies selling components or complete systems. The National Solar Heating and Cooling Information Center, P.O. Box 1607, Rockville, MD 20850 provides a broad range of general information about solar energy.

Most State energy offices have personnel assigned to provide assistance on solar energy that is applicable to local conditions. They would be helpful in locating engineers and architects.

The Cooperative Extension Service provides publications and educational programs for agricultural applications. They will have plans available as they are developed.

Source: http://www.healthguidance.org/authors/488/Bob-Bergland