During the negotiations with EU, Estonia was set an indicative tat-get to increase the share of renewable energy sources in the electricity production to 5.1% of inland consumption by the year 2010. Similarly to the rest of Europe, one of the main means to achieve this target is to install wind turbines. The current paper analyses the capability of existing oil-shale power plants to cover differences between forecasted and actual generation of wind energy and shows that participation of fossil fuel-based power plants in the compensation of fluctuating production of wind turbines eliminates part of the expected positive effect of wind energy.