All wind turbines must have a way to deal with this massive increase in available power as the wind speed goes up. In Part 1 of this series (see ESSN July 2005), we discussed the distribution of wind speeds, and how most wind comes to us at lower speeds. So, manufacturers try for the best performance between 7 and 30 mph, and design the turbine to simply? survive?winds higher than that while still producing near peak power. If the turbine was allowed to keep making power over 30 mph, it would?
Africaremains the continent with the smallest wind development. Two countries have emerged as leaders of the continent: Egypt and Morocco. The development is expected to continue in these two countries at a more rapid rate than in the past and some development is predicted in other North African and Middle East countries adding a total of 1,000 MW during the period 2006-2010 for the whole continent.
The wind turbine market in Latin America has not yet taken off. The year 2005 has only seen marginal installations. During the period 2006-2010, it is predicted that the wind turbine market will take off starting with Brazil and followed to a lesser extent by Mexico. Smaller developments will also take place in some countries of Central America as well as in Argentina and Chile.
The Asian wind turbine market will also gain considerable wind turbine market share with the development of a predicted average annual growth rate of 23.5 % during the period under consideration. The total installed capacity in the Asian continent should reach 20.1 GW by 2010, up from 7.0 GW of 2005. With a predicted installed capacity of 6,000 MW during the period 2006-2010, India will continue to be the continental leaders and the fourth country globally.
The North American wind turbine market is predicted to have the highest growth rate. From 9.8 GW installed at the end of 2005, it is estimated to reach 29.1 GW by the end of 2010, with an annual average growth rate of 24.3 %. The US wind turbine market will be the most important national wind turbine market in the world during the period 2006-2010 with a predicted average of 3,000 MW per year. There is an uncertainty with the PTC ending by the end of 2007, but all the elements indicate that it will be extended.
Until the end of the current decade, the cumulative capacity of wind energy installations is predicted to reach 134.8 GW, more than double of the present installed capacity. The average annual cumulative growth rate during the period 2005-2010 will be 18 %, compared with 28 % during the period 2000-2005. The annual installed capacity is predicted to reach 17.8 GW in 2010, an increase of 55 % from the11.5 GW installed in 2005.
Due to improved technology, wind power generation is increasingly competitive with conventional fossil fuel sources. At the best sites, the costs for wind power production are already on a par with new coal or gas fi red power plants. If the environmental and social costs of power generation were included in electricity prices, wind power would already be cheaper than any other electricity generating technology.
Thanks to twenty years of technological progress, wind turbines have come a long way since they were fi rst deployed in the 1980, and size, effi ciency and ease of use have increased considerably. A wind farm today acts much more like a conventional power station, and modern turbines are modular and quick to install. This is of particular importance for countries in need of a rapid increase in electricity production.
he impetus behind wind power expansion has come increasingly from the urgent need to combat global climate change, which is one of the greatest threats the world is facing. The UN’s Intergovernmental Panel on Climate Change projects that verage temperatures around the world will increase by up to 5.8°C over the next century, resulting in fl ooding, droughts and violent climate swings. There is a broad consensus now that greenhouse gas emissions must be cut drastically to limit the widereaching environmental consequences.
Three bladed wind turbine :Turbines used in wind farms for commercial production of electric power are usually three-bladed and pointed into the wind by computer-controlled motors. These have high tip speeds of over 320 km/h (200 miles per hour), high efficiency, and low torque ripple, which contribute to good reliability. The blades are usually colored light gray to blend in with the clouds and range in length from 20 to 40 metres (65 to 130 ft) or more.