Use of wood fuel is a sustainable solution of district heating system development for the countries which do not have fossil fuel reserves, but have rich forest resources. The study analyzes the options for wood fuel use in Latvia's capital, Riga. The STATGRAPHICS Forecasting and regression analysis modeling tools were used to develop two possible forecasting curves showing the trend of wood fuel use until the year 2020. The results show that the share of the amount of heat produced by wood fuel in Riga could reach 25% of total heat demand if the current trend continues.