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Snow-coatged solar hot water heating panels on a Poughkeepsie NY rooftop (C) 2013 Daniel FriedmanSolar & Renewable Energy
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This page provides an index to key articles about solar energy design & products.

We include descriptions of solar energy system types, uses, and best practices for solar energy system installation.

These solar energy articles discuss in deteail how to choose, install, diagnose, & repair renewable energy systems for buildings including active and passive solar heating & solar hot water heating systems, solar powered electrical systems (photovoltaics), along with building insulation & ventilation design & retrofit tips to save energy where solar or other alternative energy systems are in use or planned.

InspectAPedia tolerates no conflicts of interest. We have no relationship with advertisers, products, or services discussed at this website.

- Daniel Friedman, Publisher/Editor/Author - See WHO ARE WE?

Solar Energy Designs & Retrofit Improvements in Buildings

Solar electrical power array, San Miguel de Allende (C) Daniel Friedman

The green power solar electrical panel array shown above is distributed by Desmex Solar and is installed in San Miguel de Allende, Mexico.

The solar energy system shown here and just below provides all of the electrical energy required by a small restaurant, including powering lighting and nine refrigerators and coolers in the building.

To find what you need quickly, if you don't want to scroll through this index you are welcome to use the page top or bottom SEARCH BOX to search InspectApedia for specific articles and information.

Article Contents

Our page top photo illustrates an extensive photovoltaic solar panel system installed on a building providing commercial rental space in New Paltz, N.Y. The property owners expect a rapid payback on the system cost thanks in part to government incentive program assistance.

Satisfied with the performance of the solar panels in reducing building electrical costs the owners intend to install a similar system on residential apartment space in New Paltz as well.

Solar electrical power array, San Miguel de Allende (C) Daniel Friedman

Solar Energy Articles, Information, Products, Sources

Solar heating installation (C) Daniel FriedmanOur articles listed below provide detail about solar energy sources, installation, maintenance, inspection, diagnosis, and repair.

Articles in this series include solar energy, solar heating, solar hot water, and related building energy efficiency improvement articles including material reprinted/adapted/excerpted with permission from Solar Age Magazine - editor Steven Bliss.

We include links to solar design guides and other authoritative sources.

Our photograph (left) shows solar panels, both photovoltaic and domestic hot water heating systems, on a rooftop in Surprise, Arizona.

According to the Pennsylvania DEP who provide a nice introduction to solar power, solar energy systems are divided into three major categories:

  1. passive solar systems,
  2. solar-thermal systems, and
  3. photovoltaic solar systems.

The text below is adapted and expanded upon from that source:

Definition of Passive Solar Systems: Using Building Design Features to Take Advantage of & Control Solar Heat Gain

Direct solar gain (C) Daniel Friedman

Passive solar designtakes advantage of a building's structure to capture the sun's heat, either storing or distributing it, reducing the need for conventional heating, cooling and/or lighting.

Examples of passive solar design include large, south-facing windows, dark colored tile floors , stone fireplaces, brick interior walls, "sunspaces" (or greenhouses) and super-insulation.

Passive solar buildings are often equipped with features, such as overhangs and ventilation systems, which keep them cool in the summer months and warm in the winter months.

Passive solar buildings may also make use of special window glazing to control un-wanted heat loss in cold weather and un-wanted gain in hot weather.

Our passive solar gain photo (above left) is from the author's New York home.

 

The effectiveness of passive solar heating is discussed

at PASSIVE SOLAR HEAT PERFORMANCE.

See PASSIVE SOLAR HOME, LOW COST for an example of a low-budget passive solar design.

Definition of Solar-Thermal Systems: Using Solar Energy to Heat Water to Operate Electricity-Generating Turbines

Power plants often use fossil fuels as a heat source to boil water. The steam from the boiling water then rotates a large turbine, activating a generator that produces electricity. Solar-thermal concentrating systems use sunlight as the heat source, eliminating the need for fossil fuels.

There are three types of solar-thermal concentrating systems & parabolic troughs, parabolic dishes and central receivers. Parabolic troughs, primarily used for industrial purposes, are curved reflectors that focus sunlight into a line receiver in which fluid is heated.

Parabolic dishes, also used in industrial applications, are bowl-shaped reflectors that focus sunlight into a small receiver through which passes a heat-transfer fluid. Central receivers, which have traditionally dominated the U.S. Department of Energy's solar thermal program, are sun-tracking mirrors that focus sunlight onto a large receiver.

Residential heating of water using solar systems is not in turn for the generation of electrical power as the PA DEP outlined above, but rather to produce domestic hot water or in some cases, heat storage or to heat swimming pools.

Details are

at SOLAR HOT WATER HEATERS &

at SWIMMING POOL SOLAR HEAT, INDOOR.

Special applications of solar heating or boiling of water of interest to smaller-scale users

includes SOLAR WATER DISINFECTION such as might be used at a remote cabin or in areas where potable water is not available.

Definition of Photovoltaic Cell Solar Systems

Using Solar Energy to Create Electricity in Arrays of Devices that Change Sunlight into Electrical Energy

Solar powered street lighting, Haddonfield NJ (C) 2013 Daniel Friedman

Photovoltaic (PV) cells, or solar cells, convert sunlight directly into electricity. [A photovoltaic cell is an electrical device made of layers of semiconductor materials that are excited by sunlight and give off electrical energy.]

As the sun strikes a PV cell the semi-conducting materials within the cell absorb the sunlight, producing electricity. Solar cells are often used as simple systems that power small calculators and wristwatches.

More complicated systems provide electricity for pumping water, powering communications equipment, lighting homes, and running appliances.

Details are at PHOTOVOLTAIC POWER SYSTEMS

In residential applications, photovoltaics are also popular for remote cabins where conventional electrical power is not available.

REMOTE ELECTRIC POWER, PHOTOVOLTAIC

A series of solar cells form a PV array or "solar panel."

Between 10 and 50 solar panels are needed to power an average household. PV panels are installed on buildings in places of maximum sun and minimal shade in order to take full advantage of the sun's power.

There is very little maintenance required to sustain solar equipment.

So long as panels are kept clean, they can last approximately 20 to 30 years. Also

see SOLAR COLLECTOR EFFICIENCY COMPARISONS.

Our photovoltaic solar panel photo (above left) shows the use of passive solar energy to power street lighting in Haddonfield, New Jersey.

Solar Grid-Tied vs Distributed Solar Systems

Snow-coatged solar hot water heating panels on a Poughkeepsie NY rooftop (C) 2013 Daniel Friedman

Our photo illustrates snow-coated solar hot water heating system panels on a Poughkeepsie NY rooftop during snowy winter weather.

A solar grid-tied system links a series of solar panels through a power inverter to the utility's electric grid.

The solar panels generate a direct current (DC) by drawing on energy from the sun.

The inverter then converts that direct current to an alternating current (AC), which electronic devices and appliances can use.

Batteries are not necessary to supplement the system and any excess electricity generated by the solar panels is redirected by the inverter back into the grid where it can be used on other premises.

Distributed solar systems work independently from a utility's electric grid, using batteries to store the power.

Similar to a grid-tied system, distributed solar panels typically use a power inverter to convert the direct current from the sun into an alternating current, to be used on location. However, some systems function without an inverter and run only DC appliances.

Solar Energy Information at InspectApedia

Solar Water Heating Systems

Closeup of a solar water heater collector unit (C) Daniel Friedman

Solar water heaters use renewable energy - sunlight - collected in outdoor rooftop or ground-mounted solar collectors to heat water which is circulated by a pump between a hot water storage tank and the panels.

The upper end of a simple solar water heater collector is shown in our photo at left. Look closely and behind the corrugated plastic surface, at the top you can see the horizontal black tubing that moves water through the top end of this collector.

Solar water heaters have been in use for decades, with popular use at remote cottages or off-the-grid buildings and are likely to see increasing use in much of the world as energy costs continue to climb.

List of Solar Heating Systems, Panels, Controls, Components, Packaged Systems

Schematic of a solar water heater hookup (C) InspectAPedia.com - Lennox IndustriesSketch courtesy of Lennox Industries.

Solar Heating Design, Installation, Repair Books, Solar Pumps, Manuals

Alternative Energy, Green Energy, Energy-Savings Topics & Articles Supporting Solar Energy Systems & Designs

See the INDEX to RELATED ARTICLES given below


...

Continue reading at PASSIVE SOLAR DESIGN METHOD or select a topic from the closely-related articles below, or see the complete ARTICLE INDEX.

Or see these

Recommended Articles

Suggested citation for this web page

SOLAR ENERGY SYSTEMS at InspectApedia.com - online encyclopedia of building & environmental inspection, testing, diagnosis, repair, & problem prevention advice.


Or see this

INDEX to RELATED ARTICLES: ARTICLE INDEX to SOLAR ENERGY

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Citations & References

In addition to any citations in the article above, a full list is available on request.

  • [1] "Energy Savers: Whole-House Supply Ventilation Systems [copy on file as /interiors/Energy_Savers_Whole-House_Supply_Vent.pdf ] - ", U.S. Department of Energy energysavers.gov/your_home/insulation_airsealing/index.cfm/mytopic=11880?print
  • "Energy Savers: Whole-House Exhaust Ventilation Systems [copy on file as /interiors/Energy_Savers_Whole-House_Exhaust.pdf ] - ", U.S. Department of Energy energysavers.gov/your_home/insulation_airsealing/index.cfm/mytopic=11870
  • "Energy Savers: Ventilation [copy on file as /interiors/Energy_Savers_Ventilation.pdf ] - ", U.S. Department of Energy
  • "Energy Savers: Natural Ventilation [copy on file as /interiors/Energy_Savers_Natural_Ventilation.pdf ] - ", U.S. Department of Energy
  • "Energy Savers: Energy Recovery Ventilation Systems [copy on file as /interiors/Energy_Savers_Energy_Recovery_Venting.pdf ] - ", U.S. Department of Energy energysavers.gov/your_home/insulation_airsealing/index.cfm/mytopic=11900
  • "Energy Savers: Detecting Air Leaks [copy on file as /interiors/Energy_Savers_Detect_Air_Leaks.pdf ] - ", U.S. Department of Energy
  • "Energy Savers: Air Sealing [copy on file as /interiors/Energy_Savers_Air_Sealing_1.pdf ] - ", U.S. Department of Energy
  • Solar Age Magazine was the official publication of the American Solar Energy Society. The contemporary solar energy magazine associated with the Society is Solar Today. "Established in 1954, the nonprofit American Solar Energy Society (ASES) is the nation's leading association of solar professionals & advocates. Our mission is to inspire an era of energy innovation and speed the transition to a sustainable energy economy. We advance education, research and policy. Leading for more than 50 years. ASES leads national efforts to increase the use of solar energy, energy efficiency and other sustainable technologies in the U.S. We publish the award-winning SOLAR TODAY magazine, organize and present the ASES National Solar Conference and lead the ASES National Solar Tour – the largest grassroots solar event in the world."
  • Steve Bliss's Building Advisor at buildingadvisor.com helps homeowners & contractors plan & complete successful building & remodeling projects: buying land, site work, building design, cost estimating, materials & components, & project management through complete construction. Email: info@buildingadvisor.com
    Steven Bliss served as editorial director and co-publisher of The Journal of Light Construction for 16 years and previously as building technology editor for Progressive Builder and Solar Age magazines. He worked in the building trades as a carpenter and design/build contractor for more than ten years and holds a masters degree from the Harvard Graduate School of Education. Excerpts from his recent book, Best Practices Guide to Residential Construction, Wiley (November 18, 2005) ISBN-10: 0471648361, ISBN-13: 978-0471648369, appear throughout this website, with permission and courtesy of Wiley & Sons. Best Practices Guide is available from the publisher, J. Wiley & Sons, and also at Amazon.com
  • Mark Cramer Inspection Services Mark Cramer, Tampa Florida, Mr. Cramer is a past president of ASHI, the American Society of Home Inspectors and is a Florida home inspector and home inspection educator. Mr. Cramer serves on the ASHI Home Inspection Standards. Contact Mark Cramer at: 727-595-4211 mark@BestTampaInspector.com
  • John Cranor [Website: /www.house-whisperer.com ] is an ASHI member and a home inspector (The House Whisperer) is located in Glen Allen, VA 23060. He is also a contributor to InspectApedia.com in several technical areas such as plumbing and appliances (dryer vents). Contact Mr. Cranor at 804-873-8534 or by Email: johncranor@verizon.net
  • "Conserving Energy and Heating Your Swimming Pool With Solar Energy", U.S. Department of Energy

  • Desmex Solar, Blvd. José Ma. Morelos 3649, Col. Purísima de Jerez, León, Gto. C.P.37290 Tel. +52 (477) 788 06 00, Fax. +52 (477) 771 10 02, e-mail: leon@desmexsolar.com: website http://www.desmexsolar.com/
    Additional offices in
    • San Miguel de Allende, Guanajuato, Mexico - Carretera a Celaya Km. 1, Plaza Alhóndiga Local 14 (1M), Frente a Mega Comercial Mexicana, San Miguel de Allende, Gto. Tel: +52 (415) 150 73 12 e-mail: sanmiguel@desmexsolar.com, on-site contact: Alejaranda
    • Guadalajara, Mexico - +52 (33) 3165-2454 e-mail: guadalajara@desmexsolar.com,
    • Monterrey Mexico - Tel. +52 (818) 356 43 30 e-mail: monterrey@desmexsolar.com, and Mexico City - Tel. +52 (55) 2643 26 29, Fax. +52 (477) 771 10 02 e-mail: mexico@desmexsolar.com
    • Distrito Federal, Tel: 55-26-43-26-29
    • Alemania [Germany], Desmastrasse 3-5, 28832 Achim, Germany Tel: 49-4202-910-9-00 Email: ub@framex-gmbh.de

  • PASSIVE SOLAR DESIGN HANDBOOK VOLUME I [PDF], the Passive Solar Handbook Introduction to Passive Solar Concepts, in a version used by the U.S. Air force
  • PASSIVE SOLAR DESIGN HANDBOOK VOLUME II [PDF], the Passive Solar Handbook Comprehensive Planning Guide, in a version used by the U.S. Air force - online version available at this link and from the USAF also at wbdg.org/ccb/AF/AFH/pshbk_v2.pdf [This is a large PDF file that can take a while to load]
  • PASSIVE SOLAR HANDBOOK VOLUME III [PDF], the Passive Solar Handbook Programming Guide, in a version used by the U.S. Air force - online version available at this link and from the USAF also at wbdg.org/ccb/AF/AFH/pshbk_v3.pdf
  • The Passive Solar Design and Construction Handbook, Steven Winter Associates (Author), Michael J. Crosbie (Editor), Wiley & Sons, ISBN 978-047118382 or 0471183083
  • "PASSIVE SOLAR HOME DESIGN [PDF] ", U.S. Department of Energy, describes using a home's windows, walls, and floors to collect and store solar energy for winter heating and also rejecting solar heat in warm weather.
  • Pennsylvania Department of Environmental Protection, "Solar Energy" introduction and definition of types of solar energy systems, Email: RA-epcontactus@state.pa.us. Retrieved 11/30/2010, original source: http://www.portal.state.pa.us/portal/server.pt/community/Solar/10409
  • SOLAR WATER HEATERS [PDF] , U.S. Department of Energy article on solar domestic water heaters to generate domestic hot water in buildings, explains how solar water heaters work. Solar heat for swimming pools is also discussed.
  • HEAT EXCHANGERS for SOLAR WATER HEATING SYSTEMS [PDF], U.S. DOE describes the types of solar water heater heat exchange methods between the sun and the building's hot water supply
  • HEAT-TRANSFER FLUIDS for SOLAR WATER HEATING SYSTEMS [PDF] , U.S. DOE, describes the types of fluids selected to transfer heat between the solar collector and the hot water in storage tanks in a building. These include air, water, water with glycol antifreeze mixtures (needed when using solar hot water systems in freezing climates), hydrocarbon oils, and refrigerants or silicones for heat transfer.
  • SOLAR WATER HEATING SYSTEM MAINTENANCE & REPAIR [PDF] , U.S. DOE
  • SOLAR WATER HEATING SYSTEM FREEZE PROTECTION [PDF] , U.S. DOE,using antifreeze mixture in solar water heaters (or other freeze-resistant heat transfer fluids), as well as piping to permit draining the solar collector and piping system.
  • US DOE, SCALING AND CORROSION IN SOLAR WATER HEATING SYSTEMS, U.S. Department of Energy.
  • US DOE, ACTIVE SOLAR HEATING SYSTEMS [PDF], U.S. Department of Energy
  • US DOE, RADIANT HEATING SYSTEMS, U.S. Department of Energy
  • ABSORPTION HEAT PUMPS & COOLERS [PDF] , U.S. DOE
  • SOLAR AIR HEATING [PDF] U.S. DOE also referred to as "Ventilation Preheating" in which solar systems use air for absorbing and transferring solar energy or heat to a building
  • Solar Collector Efficiency Study: "Comparative study of air heating solar collectors", J. Naga Raju, Instrumentation and Services Unit, Indian Institute of Science, Bangalore 560012, India, International Journal of Energy Research, Volume 15 Issue 6, Pages 469 - 471, 14 Mar 2007:

    Abstract
    Three types of conventional solar air heater are designed such that their heat absorbing areas and the pressure drops across them are equal for equal air mass flow rates per unit collector area. The results of thermal performance tests conducted simultaneously on these collectors, under the same environmental conditions, are presented.

  • "Solar Collector and Storage Kit Made with Tire Inner Tubes", Investigators: Moaveni, Saeed , Tebbe, Patrick
    Institution: Minnesota State University - Mankato, August 15, 2008 through August 14, 2009, National Center for Environmental Research, US EPA, Quoting from the proposed study:

    Approach: A number of collector designs will be considered. Each design will be analyzed and tested for thermal performance, and ease of assembly. Once the most cost effective design with the best thermal performance is identified, an easy-to-assemble solar collector kit will be created.

    Because the proposed project makes use of solar energy, it reduces the need to burn dry-wood to heat water, and as the result it reduces pollution and the consequent hazards to human health and the environment.

    The proposed project is to be carried out by engineering students from Minnesota State University, Mankato (MSU) in collaboration with students at Kwame Nkrumah University of Science and Technology (KNUST) in Ghana as an integral part of our design curriculum.

    Expected Results: An easy-to-assemble solar collector kit that can be distributed in Ghana. The proposed solar design will reduce impacts on the environment and directly benefits human health and diminishes resource consumption.

    The proposed system will be designed for small initial cost (less than $50). It requires no additional long-term cost to operate and maintain.

  • Solar Disinfection of Drinking Water: "Final Report: Enhanced Photocatalytic Solar Disinfection of Water as Effective Intervention Against Waterborne Diarrheal Diseases in Developing Countries", National Center for Environmental Research, U.S. Environmental Protection Agency, Investigators: Dionysiou, Dionysios D. , Bandala, Erick R. , Castillo, Jordana , Dunlop, Patrick , Pelaez, Miguel A, Institution: University of Cincinnati , NIBEC, School of Electrical and Mechanical Engineering , Universidad de Las Américas-Puebla, Research Category: Pollution Prevention/Sustainable Development , P3 Challenge Area - Water , P3 Challenge Area - Materials & Chemistry
    Quoting from the above report (http://cfpub.epa.gov/ncer_abstracts/index.cfm/fuseaction/display.abstractDetail/abstract/8841/report/F)

    Conclusions:

    Photocatalytic enhanced solar disinfection using NF-TiO2 was responsible for complete inactivation of E. coli in those reactors exposed to both solar and visible light radiation. The presence of NF-TiO2 enhanced the disinfection rate efficiency of E.coli when compared to those experiments where no photocatalyst was used.

    Practical application of dye solutions as dosimetric indicator appears as very useful for determining the solar radiation dose necessary for waterborne pathogen deactivation.

    Solar water disinfection (SODIS) is a simple, environmentally friendly and low cost point-of-use treatment technology for drinking water purification. However, bacterial re-growth after short storage (24 h) of SODIS treated water has been observed.

    Seeking for improvements of SODIS performance, reduction of irradiation time and avoidance of bacteria re growth, solar based-Advanced Oxidation Technologies (AOTs), such as solar TiO2 photocatalysis, are promising enhancements to SODIS.

    Unfortunately, one of the main problems with the use of conventional TiO2 for solar applications is its limited capability to absorb only the radiation in the UV range, which is only about 5-8% of the total solar radiation.

    In this study, we employed novel nanotechnological procedures to synthesize visible light activated nonmetaldoped TiO2 (i.e., nitrogen-doped TiO2) with high surface area and immobilized on appropriate support materials that were used in novel photocatalytic reactors for water purification in rural zones in Mexico as a case study.

    In combination with visible light activated TiO2, we also propose to incorporate in our process the V trough solar collector which has never been applied to solar photocatalytic processes in the past, but has much simpler geometry and demonstrated in preliminary results performance comparable to other types of solar collectors.

    Because of its simpler geometry, the V trough solar collector is much less expensive and is attractive to applications is developing countries. This overall process for water purification was denominated “Enhanced Photocatalytic Solar Disinfection” (ENPHOSODIS).

    A complete inactivation of the bacteria was achieved when using ENPHOSODIS under solar and visible light at three different NF-TiO2 catalyst concentrations. Under dark conditions, no difference in the bacteria count was observed and no inactivation of E. coli was observed when employing visible light only.

    pH was an important influence on the bacteria resistance to solar radiation. E. coli was able to survive for longer radiation periods at pH 7 and 7.5 than at lower or higher pH values (i.e., 6, 6.5 and 8). An azo dye, acid orange 24 (AO24), was explored for the development of a UV dosimetric indicator for disinfection.

    Complete color removal was found to be equivalent to that when water submitted to ENPHOSODIS treatment, under the proposed conditions, will get enough energy to deactivate completely the viable helminth eggs present.

    Different configurations of immobilized TiO2 photocatalytic reactors were tested under real sun conditions. Experiments under full sun and cloudy conditions showed that these photo reactors are capable of disinfection with an optimum configuration of internal and external coating along with a compound parabolic collector.


    NOTE: The perspectives, information and conclusions conveyed in research project abstracts, progress reports, final reports, journal abstracts and journal publications convey the viewpoints of the principal investigator and may not represent the views and policies of ORD and EPA.

    Conclusions drawn by the principal investigators have not been reviewed by the Agency.
  • SOLAR LIQUID HEATING [PDF] U.S. DOE, systems using liquid (typically water) in flat plate solar collectors to collect solar energy in the form of heat for transfer into a building for space heating or hot water heating. The term "solar liquid" is used for accuracy, rather than "solar water" because the water may contain an antifreeze or other chemicals.
  • "Side by Side Testing of Eight Solar Water Heating Systems", ETSU S/P3/00275/REP/2, DTI Pub URN 01/1292, Contractor, The Energy Monitoring Company Ltd., C Martin, M Watson, 2001

    This study compared the amount of energy that eight modern solar water heating systems could produce over an average year. Document: http://www.berr.gov.uk/files/file16826.pdf
  • In addition to citations & references found in this article, see the research citations given at the end of the related articles found at our suggested

    CONTINUE READING or RECOMMENDED ARTICLES.


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