Wind energy application problems in inland Estonia
Department of Energy Application, Institute of Technology,Estonian University of Life Sciences, Kreutzwaldi 56, 51014, Tartu;e-mail: andres.annuk@emu.ee
Abstract:
The inland regions of Estonia have not been seen as suitable economically for de-ployment of wind energy systems. Prices for technological development of wind turbines are going down, while energy prices are rising constantly. Since rural regions of Estonia are under-populated, the use of small scale wind turbine generators in these conditions is becoming more promising. Average wind speeds in mainland Estonia are 2.5–3.5 m s-1. Only a very small part of the wind speed frequency distribution (~4 ppm) exceeds 12 m s-1. More suitable for these regions are wind turbine generators which switch on at wind speeds less than 3 m s-1 and reach nominal output power at 11–12 m s-1. They have similar-looking power curves, so it is possible to model the first rising part of the curve up to maximal power by second order polynomial. Because the wind speed rarely exceeds 12 m s-1 in inland regions there is no need to model the whole power curve. The average power curve makes it possible to estimate an approximate en-ergy production of small scale wind turbine generators in a given region if the wind speed fre-quency distribution is known.
Key words:
wind energy, wind speed, wind speed frequency distri-bution, wind turbine power curve