Alternative energy
ALTERNATIVE ENERGY
Name: Schneeberger Bernhard
Class: 3 / 4 AEB 2000 / 2001
Examiner: Prof. Wurzinger Riedl
Table of contents
What is alternative energy?
Electricity and the environment: Why should we care?
Environmental factors
Conventional energy sources
Alternative technologies
Efficiency
Solar power
Solar thermal power
Photovoltaic cells
Geothermal power
Wind power
Low impact hydro power
Biomass power
Pros and cons
Words
Sources
1 What is alternative energy?
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 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?
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.
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.
3 Alternative technologies
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 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.
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
+ 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
ansammeln
agricultural
landwirtschaftlich
amount
Betrag, Menge
average
Durchschnitt
beneath
Unterhalb
combustible
leicht entzündlich
commercial power
althergebrachte Energieformen
dam
Kraftwerksdamm
decayed remains
verrottete Rückstände
demand
Anforderung
facilities
Anlagenkomplex
forestry
forstwirtschaftlich
alternative energy
Alternativenergie
green house effect
Treibhauseffekt
high impact hydro plant
Speicherkraftwerk mit hohem Damm
house-hold appliances
Haushaltsgeräte
incinerator
Müllverbrennungsofen
long- distance energy
Fernwärme
low impact hydro plant
Laufkraftwerk mit niedrigem Damm
nucleus
Kern eines Atoms
remote areas
abgelegene Orte
renewable
erneuerbar
semiconducors
Halbleiter
status quo
der jetzige Zustand
storage site
Lagerplatz
to devastate
vernichten
to emit
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
Wind energy
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
Solar thermal power
A - Pool water inlet
I - Gate valve
B - Pump
J - Fossil fuel heater (if existing)
C - Filter
K - Chlorinator (if existing)
D - Check valve
L - Warm water returns to pool
E - Gate valve 1
M - Sensor
F - Drain valve
N - Automatic control box
G - Solar collectors
O - Electric or constriction valve (collector bypass)
H - Vacuum breaker and auto air relief
P - Booster pump
Photovoltaic system
Geothermal energy
Hydro-power
Biomass incinerator
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