Bioenergy from Forage Crops--The European Perspective.

In March 2007, the European Council set course for an inte­gra­ted climate and energy policy. GHG emissions shall be reduced by 30 percent com­pared to 1990 within the framework of a post 2012 climate protection agreement. To this end, the share of renewable energies in primary energy con­sump­tion shall be increased to 20 percent by 2020. As a consequence, energy crop production is pro­moted in several European member states by additional subsidies, which may lead to a food-fuel competition for productive land. Energy efficiency (EE) therefore represents a crucial determinant of sustainable bioenergy production systems.

Biodiesel from rapeseed or sunflower currently represents the main pathway of biofuel production from arable land, while ethanol from cereals or sugar beet is of minor importance. With respect to EE, however, both pathways are outcompeted by biomethane. In Germany and Austria, anaerobic digestion of slurry and crops has evolved as an energy efficient alternative, especially when local plants are equipped with power-heat coupling. The acreage of maize, which is the dominating co-substrate for fermentation, therefore has increased substantially.

Recently, some criticism was voiced concerning the sustainability of energy crop production in view of GHG emission and soil carbon loss. Apart from EE, further indicators are required to ensure that bioenergy makes a real contribution to climate and environment protection. Hence, Germany is currently putting forward a pioneering legislation, which will result in a fundamental reorientation of biofuel subsidising by adopting sustainable biomass production and a defined GHG mitigation potential as legal restraints for biofuel production. The authors will provide an overview on the perspectives of energy crop production in the European Union by highlighting (i) Measures of promoting bioenergy via national legislation (ii) Promising grass-arable forage rotations for energy production in different EU-regions, and (iii) Research challenges to be tackled in the future.