Alternative energy- alternatywne źródła energii

Alternative energy

Most of the energy we use today comes by burning fossil fuels (for example coal, oil and gas) or generated in nuclear power stations. Unfortunately, these are not renewable sources of energy, and once they have run out. What is more, these methods of electricity generation are harmful to the environment. They emit harmful greenhouse gases, which contribute to global warming and climate change. We need to look for other ways of supplying energy which will be friendly to the environment.
As the alternative source of energy we can use for example wind powers. Wind power has been used for many years in countries like Holland and Denmark. This type of energy harnesses the power of the wind to propel the blades of wind turbines. Wind towers are usually built together on wind farms. Wind farms are actually arrays of electricity-generating wind turbines, which are tall, slim towers with two or three rotor blades at the top. Then can be as few as one and as many as thousands of wind turbines in a single array. The wind turns the blades, which spin a pole. This pole is connected to a generator, where the electricity is made. Computers monitor the wind direction and speed, and can shut down the turbines if the wind becomes too strong.
This kind of the energy has many advantages. Wind power produces no water or air pollution that can contaminate the environment, there are no by-products, such as carbon dioxide. Wind generation is a renewable source of energy, which means that we will never run out of it. What is more, wind turbines make hardly any noise and they are not unpleasant to look at, certainly not as ugly as nuclear power stations. Although wind farms do take up a lot of space, they are often located on unoccupied sites or in areas that can also be used for farming. Besides building wind farms at sea is also possible. A single wind turbine can produce enough electricity to power 375 homes and wind power supplying as much as 10% of world’s electricity demands.
On the other hand, there are disadvantages. Consistent wind is needed to ensure continuous power generation. When the wind speed decreases, less electricity is generated.
Solar power is the technology of obtaining useful energy from the light of the Sun. It is a way of using the sun’s energy as heat or to make electricity. The Sun provides approximately 1000 watts/meter² on Earth\'s surface. Solar energy has been used in many traditional technologies for centuries and has come into widespread use where other power supplies are absent, such as in space.
Solar power is a renewable resource. As long as the Sun exists, its energy will reach Earth. Solar cells can convert about 20% of the energy of incident sunlight to electrical energy. Solar cells can also be placed on top of existing urban infrastructure. In sunny countries, solar power can be used in remote locations. This way, isolated places can receive electricity, when there is no way to connect to the power line from a plant. Solar energy can be used very efficiently for heating (for example water and home) and lighting. Solar power generation releases no water or air pollution, because there is no combustion of fuels.
Geothermal energy harnesses the heat energy present underneath the Earth. Geothermal power has a very large potential if considering all the heat existing inside Earth, although the heat flow from the interior to the surface is only 1/20,000 as great as the energy received from the Sun or about 2-3 times that from tidal power.
Geothermal energy produces air or water pollution if performed incorrectly but if done correctly, will cause no physical damage. Unfortunately geothermal energy is only sufficient as source of power in certain areas of the world. At the moment Iceland and New Zealand are two of the greatest users of geothermal energy.
There are several types of water-power.
River water can be used to generate hydroelectric power. In hydroenergy, the gravitational descent of a river is compressed from a long run to a single location with a dam or a flume. This creates a location where concentrated pressure and flow can be used to turn turbines or water wheels, which drive a mechanical mill or an electric generator. An electric generator, when there is excess energy available, can be run backwards to pump water back up for later use. In this type of the power station electricity can be generated constantly, because there are no outside forces, which affect the availability of water. Hydroelectric power produces no waste or pollution. But the construction of a dam can have a serious environmental impact on the surrounding areas. Because a river valley is being flooded, the delicate local habitat of many species are destroyed. Dams are expensive to build, making the start-up costs of a hydroelectric power station very high. Hydroelectricity can only be used in areas where there is a large supply of water.
Wave power is the extraction of energy from waves in large bodies of water such as oceans and large lakes. This type of the energy exerts the minimal effect on the environment. The possibility of the use from the wave power is limited to shorelines.
The energy was, is and will be necessary to people in their life. Kind or using of the energy can be different. We need the energy in the industry, the transport, the heating or to the lighting. Especially over the recent years grows up using of the energy from renewable sources such as sun, water, wind. In the world the participation of renewable sources of energy amounts about 18% all kinds of the energy, and in the European Union- 6%. Advantages of these sources of energy more and more often notice users.