wind energy presentation 2003
TRANSCRIPT
Introduction
• Nowadays, we constantly hear terms like
“renewable sources of energy”, “protection of the
environment”, “the greenhouse effect” etc.
• In this presentation we will try to clarify these
terms and to focus on the wind energy as its main
subject.
• During the presentation, the personal contribution
of each one of us to the protection of the
environment with individual action will be stressed.
Greenhouse gases
•Dioxide of coal Dioxide of coal (CO(CO22),),
• Methane (CHMethane (CH44))
• oxides of nitrogen oxides of nitrogen
(NOx)(NOx)
• τετραχλωράνθρακες (CFC)τετραχλωράνθρακες (CFC)
Resource
SunSuninconsequential emissions of
pollutants, renewable sufficient
InstabilityExpensive technology(except for heating)
WindWind
inconsequential emissions of pollutants Renewable
sufficient
Occupies extensive region problems of maintenance
Bio-fuelBio-fuelMinimum emissions of pollutants
RenewableTransport of biomass
Use of water in the production of biomass likely repercussions in the ecosystems
WaterfallsWaterfalls
inconsequential emissions of pollutants
Free raw material
Low functional cost High cost of manufacture Repercussions in the
landscape Repercussions in the ecosystem
CoalCoalStability
SufficientHigh emissions of CO2, SO2
Non renewable sourceAccumulation of remains
OilOil
Developed technologyExceptionally flexible fuel
Limited availabilityCost of transport (particularly when it is transported
at big distances Non renewable sourceFlammable High emissions of CO2, NOx
GasGas
“relatively” friendly to the environment
Fuel of high energy value with easy handling
Limited availability Relative pollutionNon renewable source
Extensive network of distributionEmissions of CO2
Nuclear Nuclear PowerPower
Abundance of raw materialTransfer of raw material
Nuclear wasteDanger of nuclear arms spread
Radioactivity from operation and accidents
Renewable Renewable sourcessources
of energyof energy
Wind – Aiolos Greek MythologyGreek Mythology
When Arny announced to her father that she is expecting to give birth to the sons of god Poseidon, he did not believe her and he married her to a man named Metapontus, king of Ikaria. When Boiotos and Aiolos were born they were raised by king Metapontus but their stepmother Autolyte had a quarrel with Boiotos and she sent them away. Boiotos accompanied by his mother Arny went to Thessalia where he occupied a region and named it Boiotia. His brother Aiolos went to an island complex at Tirinia sea which were named Aiolic islands after him. According to some, he founded a town called Lipari. Although, he is traditionally acknowledged to have lived on one of the Aiolic islands close to Sicely, a different version places him on Gramvousa, on the northwest coast of Crete
Source: Wikipedia
What is wind?What is wind? The wind is created because different parts of the surface of the earth are dissimilarly heated by the sun.
The winds are directed from the points having high barometric (high pressure) to the points with low barometric (low pressure). During this movement they are diverted to the right on the Northern hemisphere because of the rotation of the Earth (forces Coriolis
High pressur
e
Low pressur
e
North Hemisphe
re
Direction of Win
d
Wind EnergyWind EnergyHistorical retrospectionHistorical retrospectionFor thousands of years, people have tried to make the wind their ally. They used it in order to propel windmills, to sail boats and to move objects and vehicles. That is to produce energy!
Dutch Windmills 07.08.07 16:55Pictures of windmills taken during our recent trip to Holland. They are dated from 1700. They were mainly used for draining regions and later in industry as well. They are believed to originate from distant Asia.
Nowadays, wind energy is mainly used in the production of electricity by means of wind generators, while people are trying to use it again in sea transportation - [tankers]-in order to save fuel and to reduce the emissions of CO2.
Greek Windmill – Naxos
Wind Wind generators generators
TechnologyTechnology
There are a lot of different types of wind generators which can be classified in two basic categories:
1. Those with horizontal shaft whose rotor is α type of helix and always parallels the direction of the wind and the ground.
2. Those with vertical shaft, which remains constantly stable and is vertical to the surface of the ground.
The output of a wind generator depends on its size and the speed of the wind. Its size is relevant to the needs that it is called to serve and it varies from hundreds up to millions of Watt
Anatomy of a wind Anatomy of a wind generatorgeneratorThe rotor: consists of two or three blades
made of reinforced polyesterThe transmission: consists of the main shaft, its mounts and the gear box. The generator: it is connected to the exit of an amplifier via a flexible or hydraulic contact and turns the mechanic energy into electric energy.The orientation/positioning system: it continuously drives the rotor to the direction of the wind.The tower: it supports the above electromechanical installation.The electronic table and the control panel: they are placed on the base of the tower. The control panel, monitors, coordinates and checks all the functions of the wind generator, ensuring its unhindered operation.
Anatomy of a wind Anatomy of a wind generatorgenerator
Φρένο
Άξονας χαμηλών στροφών
Κιβώτιο ταχυτήτων
Γεννήτρια ρεύματος
Ελεγκτής Λειτουργιών
Άξονας υψηλών στροφών
Σύστημα περιστροφής πτερύγων
Περιστρεφόμενο τμήμα
Κατεύθυνση ανέμου
Σύστημα περιστροφής κεφαλής
ΠτερύγιαΠύργος
Περίβλημα
Anatomy of a wind Anatomy of a wind generatorgenerator
Operation – A little bit of Operation – A little bit of PhysicsPhysics
Wind force
Wind force
Intersection of the wind generator’s rotor
Component which causes the
movement of the rotor
Component which tends to reverse the wind generator
AerodynamicsNowadays, in order to move the blades of the wind generators we apply aerodynamics in manufacturing (but also in rotating through a suitable mechanism) the blades in such way that the lift is more than ten times bigger than the drag.
Operation of a generatorOperation of a generator
According to Physics, when a frame of a conductor is rotating in a magnetic field there appears to be electric voltage at its ends. (Τhe magnetic field moves the free electrons of the conductor towards a specific direction in each rotation of the frame.
The electric voltage depends on the number of coils that the frame has the intensity of the magnetic field and the speed of rotation
Wind farmsWind farmsA number of wind generators together comprise a wind farm. These wind farms are economically preferable compared to individual wind generators because they require only one connection installation to the national power grid.
They are placed in regions with powerful winds after a thorough examination. Nowadays, for reasons that are related to the aesthetics of the landscape the wind farms are installed offshore.
Wind energy in GreeceWind energy in GreeceGreece due to its geophysical characteristics has a high wind potential with especially powerful winds on the islands of Aegean. The region of Ipeiros constitutes the only exception. The first wind farm in Europe was manufactured and operated in Greece, on the island of Kythnos in 1982. This jump start however, did not continue in the next 27 years.Nowadays the energy provided by the wind farms is about 1.850GWh and it represents the 6% of the total electric energy produced in our country. Today there appears to be a high interest in investing in wind farms.
Wind energy in Wind energy in EuropeEurope
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της μάθησης
1.0021.002
3.2413.241
428428 143143
1.0211.021
7878
3.1803.180
2.2252.225
38438423.90323.903 472472
3.4043.404
1414
3.7363.736
985985
16.75416.754
2.8622.862
433433
Development of Wind Development of Wind generators and the nominal generators and the nominal
outputoutput
Repercussions of wind Repercussions of wind farms installation farms installation
• Alteration of the natural environment
• Noise pollution
• Aesthetic nuisance or aesthetic
differentiation
• Reflection on the salvage of the
installations after the subsidies have
ceased
• Economic repercussions on other sectors
like tourism
The Earth, while it is heated by the Sun, emits infrared radiation. The greenhouse effect is caused by the absorption of this radiation from the atmosphere, resulting to the increase of the atmospheric temperature (Global Warming). Normally, a part of this radiation would be emitted to outer space. Now, however, it is absorbed by various gases which are produced by human activities. Such gases are the carbon dioxide (CO2), methane (CH4), the various oxides of nitrogen ([NO]x), and CFCs.The continuous destruction of the forests, which turn carbon dioxide into oxygen, results to the increase of CO2 in the atmosphere.The oxides of nitrogen are mainly produced by the engines of various vehicles. CFCs are used as propellants in various sprays and aerosols, as coolants in refrigerators, and in fire extinguishers. They are devastating for the ozone layer.The results of the global warming due to the greenhouse effect are difficult to forecast. The most probable case scenario is that the ice in the two Poles will melt and the level of the sea will rise. Regions like the Netherlands and Venice will face the danger to disappear under the sea like a new Atlantis.
The greenhouse effectThe greenhouse effect