Technology for Solar Energy Utilization, Document NO. ID/202, File 23-563, 1977 conference report, 155 pages, 1978, in English, French, or Spanish, free to local groups in developing countries, $12.00 to others, Sales No. 78IIB, from United Nations Industrial Development Organization, P.O. Box 300, A-1400, Vienna, Austria.

This is a good overview of some solar energy technologies that may eventually have relevance for developing countries. Most of the solar technologies presented are technically feasible and proven. Because they are unusual they have attracted the attention of scientists and engineers looking for exciting new technologies to work on. Yet most of these technologies are far too expensive for use in the South. Indeed, probably the majority of the technologies presented would at present be reasonable only in an isolated desert region of a rich country. On the other hand, some of these technologies may one day prove economically attractive.

A good state-of-the-art review at the beginning of the book concludes that solar distillation, solar drying, and solar water heating (if needed) are currently attractive in some circumstances. Solar engines, solar water pumps, solar photocells for electricity, and solar refrigeration are labeled not yet attractive. Later, in the contributed articles, favorable evaluation is made of solar timber kilns for decentralized applications, and Tom Lawand provides a thoughtful examination of the potential for solar cookers and solar dryers. The rest of the articles (a solar electric power plant, conversion of solar into mechanical energy, water pumps, flat plate collectors, refrigeration and cooling, active space heating and cooling) review technologies which cost far more than the poor can afford.

UNIDO suggests the local manufacture of low temperature solar devices in the near future and applied research and development efforts for high temperature applications in the more distant future. Recommended as a reference book for those active in the solar energy field in developing countries.

Solar Water Heaters in Nepal, File 23-560, book, 27 pages, by Andreas Bachmann, 1977, free photocopies from SDC; also available from SKAT and ITDG.

Here is a rare example of a book on solar water heating from a developing country. BYS (Balaju Yantra Shala) Plumbing Division has built systems in Nepal to supply hot water for bathing, washing clothes and cooking. While no detailed drawings are presented, the BYS designs are discussed, component by component. Specifications for the collector and storage tank are given, along with qualitative descriptions of construction and maintenance procedures.

Two systems are described: 1) a thermosiphon (natural circulation) system with separate collector and storage tank, and 2) a "flat tank" collector, where the collector also functions as the storage tank. This is less expensive, but only supplies a small amount of heated water at a time

A Solar Water Heater Workshop Manual, File 23-559, construction manual, 82 pages, 1979, Ecotope Group, out of print.

This manual is designed to be used in a teaching situation, with an experienced leader who can provide background knowledge and teach construction techniques. Four pages are devoted to organizing a training workshop. Ecotope Group and Rain Magazine staff have run these workshops in the Northwestern U.S. for several years, usually teaching 30 or more people from a community organization to build a solar water heater in a two day period. By teaching members of existing groups together, skills are transferred to a naturally supportive network, and more solar water heaters are likely to be eventually constructed. This approach could be used anywhere, with many different technologies.

The manual contains step-by-step instructions, with drawings, for building and installing a solar water heater. This includes siting the system, piping for natural circulation, and various open and closed loop storage alternatives.

Bread Box Water Heater, File 23-531, one large sheet of plans, $5.00 surface mail or $7.00 foreign airmail from Zomeworks, P.O. Box 25805, Albuquerque, New Mexico 87125, USA.

Drawings and a description of the principles, design, and construction of a simple and effective solar water heater are provided.

"Two tanks are painted black and placed in a glass-covered insulated box with insulated reflecting doors the sun shines through the glass onto the tank and also bounces off the reflecting doors onto the tanks .... The reflectors on the box serve to wrap the sun around the tanks rather than focus the sun on the tanks .... The doors are opened during the day to receive the sun and then closed at night to conserve.heat."

"The plans describe the construction of a solar hot water heater using two 30- gallon electric hot water tanks with electric back-up. (30-gallon drums can be substituted for the water heater tanks.) The plans also discuss the principles of the design so that an interested person can vary the construction and know generally what to expect. The plans stress the relative importance of different aspects of the design where you must be very careful and where you need not be so careful."

The Passive Solar Energy Book, File 23-544, 448 pages, by Edward Mazria, 1975, Rodale Press, out of print.

This was formerly the best book available on the design of passive solar homes and buildings. ("Passive solar" space heating relies on direct solar energy, the orientation of the structure, and the natural heat storing capabilities of selected floor and wall materials.) The format was chosen to allow the reader to go through the book in about an hour, covering only the most important concepts, and then come back for more detailed technical information on each topic. The excellent illustrations also make this a valuable tool for teaching basic concepts in a classroom.

The author begins with the fundamentals of solar energy and heat theory. He then introduces the major successful design elements and strategies, such as masonry thermal storage, Trombe walls, attached greenhouses and roof ponds. His presentation on building orientation, north side protection, and location of different kinds of living spaces helps illustrate how crucial these factors are to successful passive solar design. The important contributions offered by movable insulation, reflectors, and shading devices, and the concepts behind summer cooling are also discussed.

The author notes that "more energy is consumed in the construction of a building than will be used in many years of operation," and recommends the use of relatively low-energy-consuming materials such as "adobe, soil-cement, brick, stone, concrete, and water in containers; for finish materials use wood, plywood, particle board and gypsum board."

A full third of this book contains the information needed for calculating solar angles, solar radiation falling on tilted and vertical surfaces, shading effects, space heat loss in winter, solar space heat gains and auxiliary heating required. Data is included on the solar radiation (insolation) received and space heating needs for major U.S. cities and regions.

Highly recommended.

Homegrown Sundwellings, Disk 17, File 23-537, book, 136 pages, by Peter van Dresser, 1977 and 1979, $7.95 plus $1.50 shipping and handling from The Lightning Tree, P.O. Box 1837, Santa Fe, New Mexico 87504, USA.

Peter van Dresser, one of the pioneers of solar-heated houses, built his first one in 1958. His book summarizes a two-year program to develop low-cost, owner-built, solar-heated houses. It should be read for its sound observations on sensible solar construction based on local materials, and as an introduction to passive solar home design. More extensive information for designing passive solar homes can be found in The Passive Solar Energy Book and The Solar Home Book.

Although "the Sundwellings concept is firmly rooted in the living construction traditions as well as the socioeconomic circumstances of a natural.ecological region the uplands of northern New Mexico ... it reveals principles of universal applicability .... To construct using renewable resources is not a sentimental fad in an area without exportable products to pay for imports .... In a low cash economy, it is the interactions of human resources with the immediate materials of the land that provide for the richness and fullness of life."

The total solar energy received in winter at sites in Montana, New Mexico and Arizona is greater than the requirement for home heating. The challenge is to store this energy effectively. "The basic strategy is to design the house so that its own masses mainly walls and floors are so placed, proportioned, and surfaced that they will receive and store a large measure of incoming solar energy during the daylight hours and will gently release this stored heat to the house interior during the succeeding night hours or cloudy days .... A traditional New Mexican floor either of treated and filled adobe clay or of brick or flagstone laid over sand is very well-suited .... Its sheer mass gives it great capacity to store this heat with a very slight rise in temperature. If we visualize such a floor 12 inches deep in a room 16 feet square with one exterior wall and an average window, warmed to a mere 72°F (22°C) ... it will store 40,000 BTUs of heat which will be released into the room as it cools down to say, 650F (18°C). This is sufficient heat to take care of a well-insulated room for 26 hours, with an outdoor temperature of, say, 20°F (-7°C)."

The Solar Home Book, Disk 17, File 23-554, book, 293 pages, by Anderson and Riordan, 1976, 1987 second edition $16.95 from Brick House Publishing Co., Francestown Turnpike, New Boston, New Hampshire 03070, USA.

This is one of the best books that attempt to make the design principles of solar heated homes understandable and usable for the average person. The emphasis is on passive systems (in which the building itself acts as a solar collector and storage unit, without special circulatory systems). Also covered are systems that can be added to existing homes. A chapter on do-it-yourself methods includes insulation, window box heaters, and attached greenhouses. Altogether, there are about 40 pages on the design of solar water heaters.

"Homes can be designed to respond to local climates .... Simple low-technology methods are cheaper and more reliable than the many complex, high-technology devices being employed to harness the sun's energy .... Anyone with good building skills and a knowledge of materials can take advantage of these simple methods ...." Highly recommended for Americans and other people in temperate climates interested in building a solar-heated home.

Basic Principles of Passive Solar Design, Disk 17, File 23-529, papery pages, by Fred Hopman, 1978, free from SDC (SATA) or SKAT.

SATA has reprinted this paper from the Taos Solar Association of New Mexico, USA. The author presents operating principles and design considerations for passive space heating and cooling systems, including examples of direct gain designs, Trombe walls, roof ponds, attached greenhouses and water circulation systems. Although the examples use Western architectural styles, this excellent introduction to passive solar principles is relevant to building construction in cold climates throughout the world.

Elements of Solar Architecture for Tropical Regions, Disk 17, File 23-534, booklet, 23 pages, by Roland Stultz, 1980, 1983 edition Sw. Fr. 6.50 from SKAT; also available in Spanish; also available from VITA.

One of only a few publications on the design of solar buildings in tropical regions, where cooling and protection from heat are the major objectives. This booklet concentrates on proper building orientation; cross ventilation; reflecting, absorbing, and insulating building materials; shading with trees, shutters, roof overhangs and other techniques; and evaporation of water (in arid climates) for cooling. Tables indicate some of the different considerations for buildings in humid vs. arid regions. A good illustrated introduction to the topic; many of these concepts have long been a part of indigenous architecture in different parts of the world, but have begun to disappear in the last few decades.

Solar Dwelling Design Concepts, Disk 17, File 23-551, book, 146 pages, American Institute of Architects Research Corporation, out of print.

This volume presents principles in easy-to-understand terms for both passive and active solar heating and cooling of homes. Intended for architects, the emphasis is on the integration of solar concepts with traditional Western home designs. Factors influencing design are also covered, such as climate comfort and choice of building site.

Thirty-two solar home designs are described, with architectural drawings, to show a variety of passive and active building concepts already in use. Although these designs are from the U.S., the concepts could be adapted by building designers in other temperate climates.

A Bibliography for the Solar Home Builder, Disk 17, File 23-530, booklet, 38 pages, by Dr. Donald W. Aitken, 1979, out of print in 1986.

"The market is responding to the surging popularity of solar energy with a flood of books and reports .... Some of these are truly excellent, while others are thinly disguised attempts to sell something .... The following bibliography summarizes only the books and reports with which I am personally familiar and that I feel to be the most useful, honest, and worth the cost." This booklet describes 71 publications on solar home design, information for the beginning solar home builder, and advanced solar studies as well as a few general works on solar energy as an alternative for the future. It is especially useful because the annotations are cross referenced, with notes on which publications contain the most information on particular topics.

Also includes listings of solar energy societies and journals. A good "source book" on solar home building, oriented toward applications for the West Coast of the USA.

The Food and Heat Producing Solar Greenhouse: Design, Construction, Operation, Disk 17, File 23-565, book, 159 pages, by Bill Yanda and Rick Fisher, 1980, $10.75 postpaid from John Muir Pubs., P.O. Box 613, Santa Fe, New Mexico 87504, USA.

An excellent construction manual for a low-cost attached greenhouse that can provide both some house heating and fresh vegetable production in cold climates. Many of these have been built by low-income families in the mountain regions of.the western United States.

Although these designs come from a North American environment, it seems likely that they may be applied to the highlands of tropical countries and any colder areas of the globe where space heating is a priority. Attached greenhouses employ a "passive" solar heating concept. The structure acts as both a collector and a storage unit for solar energy, through the heat-absorbing combination of glass or plastic, concrete, adobe, stone and/or water-filled containers. During daylight hours, the last four of these substances store heat, and at night they radiate it to the living spaces. No expensive, complicated, or breakdown-prone devices such as pumps, heat exchangers, bulky collectors, or massive storage tanks are required. All that is needed is a good design and an active and alert person to regulate the vents, openings and natural energy flows in the dwelling.

Community content is available under CC-BY-SA unless otherwise noted.