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Wind energy is renewable, economic, safe and good for the environment. Our energy future is uncertain. As energy demand increases, UK's traditional fuels of oil, coal and gas are running out. By 2020, the UK may need to import gas to cater for up to 80% of our electricity needs and any interruption in that supply could leave the UK without power. The wind is a free energy source, widely available and will never run out. Electricity generated from the wind will be vital in building a secure and sustainable energy future that will help keep the lights on in Britain.
Wind turbines generate electricity without generating carbon dioxide or any other greenhouse gases. Most turbines have a life expectancy of 20-25 years, so they will generate at least 24 times the energy used in manufacture and installation. At the end of a wind farm's working life, the area can be restored at low financial and environmental costs. Currently in the UK, there is close to 4GW of installed wind energy capacity, this is saving 6 million tonnes of coal per year, and the associated CO2 emissions of 4 329 408 tonnes of CO2 annually.
Unlike nuclear power, wind energy is much safer in case of an accident. Even more it will never be a target of terrorist attacks and safety measures are of much less extend. Wind energy is one of the safest energy technologies, and enjoys an outstanding health and safety record. In over 20 years of operating experience and with more than 50,000 machines installed around the world, no member of the public has ever been harmed by operating wind turbines. Wind farms could be a lot cheaper than nuclear power plants as the main costs relate to construction and planning. After that happens, the running costs are close to zero in comparison to nuclear plants. The main disadvantage of wind farms is that there is little experience in doing large scale projects for this kind of energy production and investors or governments might be more sceptical in approving this approach.
The possible obstacles that might come in the way of building these wind farms could come from the nearby residents in the area. Complaints about wind farms being noisy or that the house prices in the area might drop, have happened in the past and will happen in the future.
Air is a fluid like any other except that its particles are in gas form instead of liquid. And when air moves quickly, in the form of wind, those particles are moving quickly. Motion means kinetic energy, which can be captured. In the case of a wind-electric turbine, the turbine blades are designed to capture the kinetic energy in wind. When the turbine blades capture wind energy and start moving, they spin a shaft that leads from the hub of the rotor to a generator. The generator turns that rotational energy into electricity. Generating electricity from the wind is all about transferring energy from one medium to another.
The simplest possible wind-energy turbine consists of three crucial parts:
Rotor blades - The blades are basically the sails of the system. In their simplest form, they act as barriers to the wind. When the wind forces the blades to move, it has transferred some of its energy to the rotor.
Shaft - The wind-turbine shaft is connected to the centre of the rotor. When the rotor spins, the shaft spins as well. In this way, the rotor transfers its mechanical, rotational energy to the shaft, which enters an electrical generator on the other end.
Generator - A generator is a pretty simple device. It uses the properties of electromagnetic induction to produce electrical voltage. Voltage is essentially electrical pressure - it is the force that moves electricity, or electrical current, from one point to another. So generating voltage is in effect generating current. A simple generator consists of magnets and a conductor. The conductor is typically a coiled wire. Inside the generator, the shaft connects to an assembly of permanent magnets that surrounds the coil of wire. In electromagnetic induction, if you have a conductor surrounded by magnets, and one of those parts is rotating relative to the other, it induces voltage in the conductor. When the rotor spins the shaft, the shaft spins the assembly of magnets, generating voltage in the coil of wire. That voltage drives electrical current (typically alternating current, or AC power) out through power lines for distribution.
Land-based wind energy has the potential of covering six times the world's electricity consumption, or one time the world's total energy consumption.
The energy consumption for production, installation, operation and decommission of a wind turbine is usually earned back within 3 months of operation.
After decommissioning wind turbines, even the foundations are removed.
Conventional and nuclear plants also have sudden unpredictable outages. Statistical analysis shows that 1000 MW of wind power can replace 300 MW of conventional power.
More recent wind farms have their turbines spaced further apart, due to the higher capacity of the individual wind turbines. They no longer have the cluttered look of the early wind farms.
It is possible to hold a conversation directly underneath a modern wind turbine without any difficulty whatever and without raising one's voice. The modern turbine is quieter than its predecessors owing to improvements in the blade design.
Studies show that the number of birds and bats killed by wind turbines is negligible when compared with other human activities such as traffic, hunting, power lines and high-rise buildings.
There is a perception that wind farms are noisy and not aesthetic.
The large number of turbines required for a viable wind farm, and the huge number of wind farms required to meet the ambitious goals of the wind energy industry and governments, ensures that more people will be affected by them.
The construction of a large wind energy facility is also far from ecologically benign in previously undeveloped locations. It requires wide straight flat roads, a large hole filled with tons of steel and concrete to secure each giant assembly, clearing of trees in wooded areas and a transformer and power lines for each turbine.
Sitting wind farms offshore can address these objections in some cases while raising other issues, such as dangers to navigation and the possible adverse effect of low-frequency vibration on aquatic life.
Another important complaint is that wind turbines kill many birds and bats. Siting generally takes into account bird flight patterns, but most paths of migration, particularly for birds that fly by night, are unknown. A survey at Altamont Pass, California conducted by a California Energy Commission in 2004 showed that turbines sited there killed 4,700 birds during the study, however it can also be argued that the environmental effects of other methods of electricity generation are potentially infinitely more dangerous if an holistic approach is taken to the issue.
Advantages of nuclear power compared to wind power
Nuclear power costs about the same as coal, so it's not expensive to make.
It does not produce smoke or carbon dioxide, so it does not contribute to the greenhouse effect.
It produces huge amounts of energy from small amounts of fuel.
Nuclear power is reliable.
Disadvantages of nuclear power compared to wind power
Although not much waste is produced, it is very, very dangerous.
It must be sealed up and buried for many thousands of years to allow the radioactivity to die away.
For all that time it must be kept safe from earthquakes, flooding, terrorists and everything else. This is difficult.
Nuclear power is reliable, but a lot of money has to be spent on safety - if it does go wrong, a nuclear accident can be a major disaster.
People are increasingly concerned about this - in the 1990's nuclear power was the fastest-growing source of power in much of the world. In 2005 it was the second slowest-growing.