The start of the organized market for intraday power trading on the Croatian Power Exchange d.o.o. (CROPEX) created the prerequisites for further development of the intraday market in Croatia in terms of liquidity and number of market participants. Pursuant to the Act on Renewables, HROTE is designated as the ECO balance group manager with the obligation to: run the ECO balance group, plan the production of electricity for the ECO balance group and to sell the electricity produced from the ECO balance group in a transparent and unbiased manner on the electricity market. In accordance with the foregoing, the subject of the research is the forecasting of production from renewable energy sources, in particular the forecasting production of wind power plants on the intraday level, i.e. during the delivery day, with the aim of reducing the balancing costs that occur due to differences in plan and production. The hypothesis is based on the assumption that it is more profitable to forecast and trade renewable energy sources on the intraday electricity market against day-ahead planning and day ahead trading. The hypothesis has been tested on actual data from the forecasts and realizations of the wind power plants, the trading simulation on the CROPEX day ahead and intraday market and the simulation of the imbalance settlement. The research in this paper confirmed that trading based on the intraday forecasting of wind power plants production on the CROPEX intraday market will save on imbalance settlement costs for the ECO balance group, and thus the need for future power reserves by the Croatian TSO. As the analysis has shown, the intraday production forecast of the wind power plants will have direct positive effects on reducing the imbalance settlement cost of the ECO balance group at the level of up to HRK 20M. This will improve the stability of the Republic of Croatia's power system and its more efficient management, all of which will increase the overall security of supply.