The European Union's energy strategy and environmental policies are achieving a sustainable, low-carbon and environment friendly economy by combating global warming and increasing production of energy from renewable sources. These sources, which are characterised with high investment costs of required use of appropriate support mechanisms as introduced by relevant laws. The article presents the current state and perspectives of using renewable energy sources in Poland, especially wind power. The economic analysis of investment in wind farms in Poland is presented according to a new act on renewable energy sources. This publication show how important appropriate government support is for producers of green energy.