Users Guide to Off-Grid Energy Solutions
Users Guide to Off-Grid Energy Solutions
Renewable Energy Resources (RE) Fact Sheet
Renewable energy resources (RE) are generally referred to those energy resources that can be replaced or regenerated continuously, and completely, over a short period of time. There are plentiful and varied renewable energy resources. Renewable energy has been used by humanity as the primary source of energy since the beginning of history, whether for drying meat, fruits and skins, or for cooking food. Renewable energy has been harnessed for more industrialised and complicated processes such as transport (wind for sailing) and grain grinding (first hydropower, later wind milling) for over a thousand years.
Biomass (in the form of charcoal) and hydropower fuelled the Industrial Revolution in Europe and North America before the use of fossil fuels in the latter part of the 18th Century. Renewable energy still comprises a major form of the energy consumed in the developing world. Even in countries as industrially developed as Austria, Sweden and Finland, renewable energy currently accounts for over 20% of all primary energy production and consumption. In the remotest areas of the world, where grid electricity has yet to reach, renewable energy will often play some, if not a major role in meeting off-grid electricity and energy needs. It is for that reason that so much attention is paid in this guidebook to renewables.
The sun's energy is ultimately the source of virtually all renewable energy available on the earth. The sun provides light for heating and generating electricity. It also is the key energy force for photosynthesis for plant (biomass production). Its energy sets the world's weather, thereby affecting rainfall and, by consequence, hydropower, and wind. Tides are a product of the earth's gravitation balance with the moon and the sun. Waves are caused by a combination of the earth's spin and weather, and tides. The following are considered by all as renewable energy resources:
Geothermal energy is renewable, and its energy can only remotely be attributed to the sun in so far as the earth remains within the sun's gravitational sphere. There are definitional issues with whether the following are renewable or not:
More contentious yet is whether the following should be considered renewable:
Energy from waste is regarded by some as renewable, while others cite that were wastes not produced in the first place (e.g., municipal and industrial wastes), there would be no renewable energy from these sources. Moreover, there is a belief among members of this school of thought that using these wastes to generate energy only encourages people to waste more. This debate seems destined to continue for some time.
Animal and agricultural wastes are also contentious issues among purists in the renewable energy community. There are those who believe all animal and agricultural wastes should be returned directly to the soil in the form of nutrients rather than converted to energy. However, no one debates that if animal wastes (and human wastes) are converted to biogas (see http://gate.gtz.de/isat/at_info/biogas/AT_biogas.html ), that this is renewable and sustainable, as the non-energy by-products (e.g., the slurry) can be, and is, used as a valuable soil nutrient enhancer.
Agricultural wastes produced through processing (e.g., rice husks, sugar bagasse, etc.) are difficult to return to the soil, so even the purists agree that it is better they be used for energy rather than left concentrated in situ to pollute the area, and the ground water. Likewise, wood wastes (e.g., sawdust, shavings, etc.) produced from the harvest of trees and from the processing of the wood, are major renewable energy resources, and most people have no problem with promoting their use as sources of energy.
So long as trees are planted to replace those harvested, renewable energy proponents have no problem with wood as a renewable resource. More contentious is whether it is actually replaced. In many parts of the developed world, such as Western and Eastern Europe, there is now more standing forest than there was 100 years ago. One the other hand, the Tropics are losing their forestry cover at a rate of anywhere between 3-5% per annum. It should be noted, however, that well over 75% of this reduction in forestry cover is attributable to land clearing for settlement, and agricultural and livestock production, and considerably less than 20% of the wood harvested in the Tropics is harvested or used for energy.
For further information, visit these sites:
1. Alternative Energy Systems Co. of Mississippi, 22 Dillard Road, Poplarville, MS 39470 USA; By Phone: +1 601 772 9966; By E-mail info@aesms.com, By WWW: http://www.aesms.com
2. German Development Assistance Programme/GTZ for renewable energy: http://www.gtz.de/home/english/index.html , and ISAT, the Information and Advisory Service on Appropriate Technology is a GATE project. GATE is a service provided by Deutsche Gesellschaft für Technische Zusammenarbeit (GTZ). Working in the adaptation and dissemination of Appropriate Technology (AT): http://193.97.174.25/isat/aboutus.html for information and contacts on a number of different renewable technologies.
3. The Center for Renewable Energy and Sustainable Technology (Crest/Solstice) provides good introduction, graphics and guides to a variety of photovoltaic applications and systems, with references to remote applications. http://solstice.crest.org/renewables/index.shtml
4. Home Power: Home Power offers some of the most extensive information on PV, other renewable systems, and systems for off-grid situation. They publish a bi-monthly magazine that is Information-Central for details on working and living with PV and other renewable and sustainable technologies. P.O. Box 520, Ashland, OR 97520 USA; By Phone/Fax: +1 916 475 3179; For Subscriptions (USA): 800-707-6585; bbs: 707-822-8640. The produce their magazines, information and other publications on CD. By Email: hp@homepower.org. By WWW: http://www.homepower.com
5. Northern Arizona Wind & Sun: Detailed information, with supplier guides, provided out of the USA. PO Box 125, Tolleson, AZ 85353 -or- 2725 E Lakin Dr, #2, Flagstaff AZ 86004. By toll free phone (USA only): 888 881 6464; (Phoenix, Arizona) 800 383 0195 (Flagstaff, Arizona) 602 877 2317 or 520 526 8017; By Fax +1 602 872 9215 or +1 520 527 0729; By Email: Windsun@Windsun.com; By WWW: http://www.windsun.com/navigation.htm
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