At the end of 2009 Hungary had 201 MW of completed wind power capacity out of the currently permitted 330 MW, which is expected to increase further, since the Energy Office of Hungary issued permits to build another 410 MW of wind power capacity. Permits are still being distributed at this time. If all these wind capacities actually get built, then within a few years up to 740 MW of wind capacity may function within the Hungarian system, equivalent to almost 8% of all domestic power generating capacity. Since the generation of wind power plants can substantially change during the day, or within hours, it is essential to analyse the impact the proliferation of these power plants will make on the Hungarian electricity system, with special attention to the volume of regulating power the system operator demands. In our study we take a look at the data of wind power generation in the first quarter of 2010, evaluating the degree to which the production of these plants can be forecasted. Furthermore, we show how the uncertainties originating from the fluctuation of wind power generation can be reduced.