Wind energy has become an increasingly popular source of energy used by man. Its history began over 2500 years ago with windmills that irrigated farmlands, and then with the Dutch windmills and wind-powered sawmills. At present, wind turbines convert the air velocity (wind power) into electricity by means of windmills with usually three long blades.
Before making a decision on the selection of a place where a wind turbine is to be placed, a person should carry out a detailed study of wind force in the selected location. Such tests and measurements should last for at least one year, and a single test should be performed every 10 minutes during this period. On the base of such test, it is possible to determine, with a fair degree of accuracy, the volume of produced energy in respect of the turbines to be installed.
Wind energy depends on its speed to the power of three; therefore, the location of windmills constitutes an extremely important aspect. Suitable locations are those where the prevalence of strong winds of 10-20 m/s is the highest. Highly advanced windmill generators operate with the wind speed from 3 to 30 m/s.
A conventional power plant has a capacity as high as 1 GW. To generate the same power, we would have to use one thousand wind generators. In order to optimise the use of places with favourable localization conditions, there are built wind power plants consisting of many turbines placed close to one other, the so-called wind farms.
The problems of using wind power in Poland are further enhanced by troubles arising from the energy policy of companies that are energy consumers. They want to be provided with a constant volume of supplies, but it is not an easy task in our climate zone. It should be added here that the process of investment financing creates an additional difficulty as it is highly cost-consuming, and, as a result, it does not find support in banks' credit policies.