Wind Power

Wind is a form of solar energy. Winds are caused by the uneven heating of the atmosphere by the sun, the irregularities of the earth’s surface, and rotation of the earth..

The means to harness wind flow for electricity generation are the wind turbines (W/T). Modern wind turbines fall into two basic categories: the horizontal-axis W/T, like the traditional farm windmills used for pumping water, and the vertical-axis design, like Darrieus model, where the rotation of blades is realized around a vertical axis. Most large modern wind turbines are horizontal-axis turbines.

It should be highlighted that the characteristic factors of wind are the following:

• Wind speed
• Wind direction
• Turbulence
• Wind shear – variation of wind over vertical distance

Germany and Spain are among the leaders of installed wind power capacity in Europe. According to EWEA (European Wind Energy Association) statistics, the total installed capacity in European Union at the end of 2011 was 93.957GW, when in Greece there were 1,629MW – an increase of 23% in its installed capacity compared to 2010 and an additional 3% capacity installed in 2001 in EU.

(source: Wind in power – 2011 European statistics, EWEA)

(source: Wind in power – 2011 European statistics, EWEA)