To act against the negative effects of climate change, the European Union (EU) has increased its efforts in the field of renewable energies. This led to the definition of national and EU wide targets for the share of energy from renewable sources in gross final consumption of energy by the year 2020 for each EU-Member state and the Union as a whole. To reach these aims without jeopardising other important aims like food security and nature conservation, sustainable systems of recovery of renewable... Mehr