Wind Energy – Renewable energy by harnessing wind power – Answer for Emission problem:
People try to make many assumptions against wind turbines for generation of wind energy; but the fact remains, wind energy is most suitable form of renewable energy we can have to replace coal fired / nuclear powered / and even oil fired power plants in the near future. In support various points are discussed below:
1. Wind power is a clean, renewable source of energy which produces no greenhouse gas emissions or waste products. Power stations are the largest contributor to carbon emissions, producing tones of CO2 each year. We need to switch to forms of energy that do not produce CO2. Just one modern wind turbine will save over 4,000 tones of CO2 emissions annually.
2. The average wind farm will pay back the energy used in its manufacture within 3-5 months of operation. This compares favorably with coal or nuclear power stations, which take about six months.
3. A modern wind turbine is designed to operate for more than 20 years and at the end of its working life, the area can be restored at low financial and environmental costs. Wind energy is a form of development which is essentially reversible – in contrast to fossil fuel or nuclear power stations.
4. A modern wind turbine produces electricity 70-85% of the time, but it generates different outputs depending on the wind speed. Over the course of a year, it will typically generate about 30% of the theoretical maximum output. This is known as its load factor. The load factor of conventional power stations is on average 50%. A modern wind turbine will generate enough to meet the electricity demands of more than a thousand homes over the course of a year.
5. All forms of power generation require back up and no energy technology can be relied upon 100%. Variations in the output from wind farms are barely noticeable over and above the normal fluctuation in supply and demand.
6. The cost of generating electricity from wind has fallen dramatically over the past few years. Between 1990 and 2007, world wind energy capacity doubled every three years and with every doubling prices fell by 15%. Wind energy is competitive with new coal and new nuclear capacity, even before any environmental costs of fossil fuel and nuclear generation are taken into account. As gas prices increase and wind power costs fall – both of which are very likely – wind becomes even more competitive, so much so that some time after 2010 wind should challenge gas as the lowest cost power source. Furthermore, the wind is a free and widely available fuel source, therefore once the wind farm is in place, there is no fuel requirement or no waste related costs.
7. In future, we will need a mix of both onshore and offshore wind energy to meet the challenging targets on climate change. At present, onshore wind is more economical than development offshore. However, more offshore wind farms are now under construction. Thus, prices will fall as the industry gains more experience.
8. Wind energy is a benign technology with no associated emissions, harmful pollutants or waste products. In over 25 years and with more than 75,000 machines installed around the world, and there is no report of any body has ever been harmed by the normal operation of wind turbines.
9. The evolution of wind farm technology over the past decade has rendered mechanical noise from turbines almost undetectable with the main sound being the aerodynamic swoosh of the blades passing the tower.
10. We need to act now to find replacement power sources - wind is an abundant resource, and therefore has a vital role to play in the new energy portfolio all over the world.
Average onshore turbines discussed here is of capacity 1.8 MW. For many on-going projects at present the capacity over 2 MW turbines are being installed. Offshore, turbines currently being installed are rated at 3 MW, and it is expected that this will rise to a typical 5 MW per machine by 2010.