ALTERNATIVE ENERGY Table of contents 1 What is alternative energy? 2 Electricity and the environment: Why should we care? 2.1 Environmental factors 2.2 Conventional energy sources 3 Alternative technologies 3.1 Efficiency 3.2 Solar power 3.2.1 Solar thermal power 3.2.2 Photovoltaic cells 3.3 Geothermal power 3.4 Wind power 3.5 Low impact hydro power 3.6 Biomass power file:///d /Refs/_To%20Do/zips/Alternative.html (1 von 13)02.03.2006 16:06:56
4 Pros and cons 5 Words 6 Sources 1 What is alternative energy? Stelle eine contains a graphic at this Alternative power, or alternative energy is electricity that is produced in a clean way by using environmentally friendly basic material or sources. The basic materials could be renewable ones, like biomass or natural gas. Alternative sources are more or less powered from the sun. For example solar energy, wind energy and all kinds of hydro power. Some others, like geothermal, are powered from the geothermal heat beneath the earth s surface. The target is to minimize all kinds of pollution. But it is not so easy to force alternative energy. As long as commercial power sources (coal, oil, nuclear, hi-impact hydro) are cheaper than alternative energy, people will use comercial sources. Both new techniques have to be developed and environmental factors have to be file:///d /Refs/_To%20Do/zips/Alternative.html (2 von 13)02.03.2006 16:06:56
right to keep the price low. For example, geothermal power could be used almost anywhere at Iceland, but hardly in Austria. 2 Electricity and the environment: Why should we care? Stelle eine contains a graphic at this Today, the electric power system is the largest single source of industrial air pollution, besides traffic. Conventional sources of electricity harm human health, destroy ecosystems, add to global warming and have high economic costs. Air pollutants are the major cause of asthma attacks to children and grown ups. Billions of liters of water are used to condense overheated steam in thermal power plants. This heated water can devastate fish population and coral reefs. Like el-nino is warming up the sea, which is caused by the greenhouse effect. Smog, acid rain and heavy metals harm the health of people all over the world. Climatic changes and environmental damage are serious indicators that the status quo is unacceptable. file:///d /Refs/_To%20Do/zips/Alternative.html (3 von 13)02.03.2006 16:06:56
Stelle eine contains a graphic at this Stelle eine contains a graphic at this Stelle eine contains a graphic at this Oil, coal or other petroleum-based recources are called fossil fuels. They are formed by the decayed remains of prehistoric plants and animals. Burning these fuels creates greenhouse gases that accumulate in the atmosphere and allow high level ultraviolet radiation to pass through. Also sulfur dioxide, nitrogen oxide and carbon oxide are released. High impact hydro-electric plants damage their surrounding area with their big dams. Also natural river flows are changed and fish populations are killed. Nuclear energy is produced by causing changes in the nucleus of the atom. There is no air pollution but nuclear plants create dangerous radioactive wastes. They are difficult to dispose and last for centuries. There are no permanent storage sites for this kind of waste. file:///d /Refs/_To%20Do/zips/Alternative.html (4 von 13)02.03.2006 16:06:56
Stelle eine contains a graphic at this 3 Alternative technologies Stelle eine contains a graphic at this Stelle eine contains a graphic at this Efficiency is the cleanest source. Using energy saving services lessens the demand for electricity. Buying economical household appliances and low fuel cars help to keep the environment clean. The sun s radiation is used directly to produce energy, which could be produced in two ways. Solar thermal and photovoltaic systems. Solar thermal systems use the sun s energy to heat water or transform it into steam. Heated water is used to heat for example a swimmingpool. The steam is used to turn a turbine and a generator, which produce the electric energy. Photovoltaic panels, commonly called solar cells or modules, use semiconductor materials to convert sunlight direct into electricity. These panels are used in remote areas. It is cheaper than stringing miles of file:///d /Refs/_To%20Do/zips/Alternative.html (5 von 13)02.03.2006 16:06:56
Stelle eine contains a graphic at this Stelle eine contains a graphic at this electrical wire. The price of solar energy, which was once very high, has dropped by half every five years over the last 25 years. Windmills or turbines are used to produce electricity. Wind power emits no pollution. If care is taken to avoid placing the windmills in undeveloped areas, these generators can have relative little impact on the land. Using wind is economical in areas where the average wind speed is at least 20 kilometers per hour. Although a single wind turbine can produce a usable amount of electricity, most wind power is produced in wind farms. These are large groups of turbines grouped together on a site. Wind power is one of the cleanest sources that can be used. And the cost- power relation is better than for example for solar power. The geothermal heat in deep areas beneath the earth s surface is used to produce overheated steam. This steam can be used to produce electricity or long-distance energy. These plants emit very little air pollution and have minimal impact on the environment. They are also very economical. file:///d /Refs/_To%20Do/zips/Alternative.html (6 von 13)02.03.2006 16:06:56
Stelle eine contains a graphic at this Stelle eine contains a graphic at this Energy from flowing water is the oldest form of using power from nature. Low impact hydroelectric plants convert a renewable energy (water flows) into electricity and don t emit any air pollution. Planning the dam carefully may cause new eco-systems for animals and plants. If dams also have fish ladders and if they fit into the nature, this is a very clean form of energy. Organic material, called biomass, can be burned in an incinerator to produce energy. Biomass recources include agricultural, forestry and food processing byproducts. In new facilities the biomass is converted into a combustible gas. Although biomass produces air pollution, it s a more green and renewable power source than petrol-based fuels. 4 Pros and cons enthält an dieser Stelle eine contains a graphic at this enthält an dieser Stelle eine contains a graphic at this file:///d /Refs/_To%20Do/zips/Alternative.html (7 von 13)02.03.2006 16:06:56
+ Using alternative energy and renewable sources helps to reduce harmful emissions to our environment. Then our seriously impacted nature could recover. This will increase quality of life for this and all further generations. - At this time alternative energy is more expensive than con-ventional energy. If conventio-nal power stations will be closed, lots of people will loose their jobs. But if new techniques are invented, and they sell good, prices will be reduced. And one should never forget thinking of our and our childrens environment, even if alternative power is more expensive. 5 Words accumulate agricultural amount average beneath combustible commercial power dam decayed remains demand facilities forestry alternative energy ansammeln landwirtschaftlich Betrag, Menge Durchschnitt Unterhalb leicht entzündlich althergebrachte Energieformen Kraftwerksdamm verrottete Rückstände Anforderung Anlagenkomplex forstwirtschaftlich Alternativenergie file:///d /Refs/_To%20Do/zips/Alternative.html (8 von 13)02.03.2006 16:06:56
green house effect high impact hydro plant house-hold appliances incinerator long- distance energy low impact hydro plant nucleus remote areas renewable semiconducors status quo storage site to devastate to emit Treibhauseffekt Speicherkraftwerk mit hohem Damm Haushaltsgeräte Müllverbrennungsofen Fernwärme Laufkraftwerk mit niedrigem Damm Kern eines Atoms abgelegene Orte erneuerbar Halbleiter der jetzige Zustand Lagerplatz vernichten aussenden, abgeben 6 Sources www.repp.org www.dir.yahoo.com/science/energy/biomass www.dir.yahoo.com/science/energy/free_energy www.dir.yahoo.com/science/energy/geothermal www.dir.yahoo.com/science/energy/solar_power www.dir.yahoo.com/science/energy/renewable www.fortunecity.de/over.htm www.howstuffworks.com file:///d /Refs/_To%20Do/zips/Alternative.html (9 von 13)02.03.2006 16:06:56
Wind energy Stelle eine contains a graphic at this A M E D F I G H K L B C A J A Rotor blades H Electronic transformer B Hub I Hydraulics system C Low speed shaft J Pillar D High speed shaft K Anemometer E Gearbox L Wind vane F Mechanical brake M Housing G Electrical generator file:///d /Refs/_To%20Do/zips/Alternative.html (10 von 13)02.03.2006 16:06:56
Solar thermal power Stelle eine contains a graphic at this A - Pool water inlet I - Gate valve J - Fossil fuel heater (if B - Pump existing) K - Chlorinator (if C - Filter existing) L - Warm water returns D - Check valve to pool E - Gate valve 1 M - Sensor N - Automatic control F - Drain valve box O - Electric or G - Solar collectors constriction valve (collector bypass) H - Vacuum breaker and auto P - Booster pump air relief Photovoltaic system file:///d /Refs/_To%20Do/zips/Alternative.html (11 von 13)02.03.2006 16:06:56
Stelle eine contains a graphic at this Geothermal energy Stelle eine contains a graphic at this Stelle eine contains a graphic at this Hydro-power Stelle eine contains a graphic at this file:///d /Refs/_To%20Do/zips/Alternative.html (12 von 13)02.03.2006 16:06:56
Biomass incinerator Stelle eine contains a graphic at this Stelle eine contains a graphic at this file:///d /Refs/_To%20Do/zips/Alternative.html (13 von 13)02.03.2006 16:06:56