Nutzung von Biomasse zur Energiebereitstellung in Deutschland / Utilization of biomass for energy generation in Germany

With a current contribution of 1.8%, biogen substances only account for very little of the net energy consumption in Germany. This is mainly due to their low cost-effectiveness when compared to fossil fuel-fired electric power plants. However, based on the current abundance, a much bigger share of the total energy generation can be covered by biomass. Various methods of converting biomass into useful energy are available which include - thermal-chemical - physical-chemical, and - bio-chemical conversion. In Germany, the main method of converting biomass into energy are thermal-chemical conversion methods, in particular the direct combustion process. For combustion many processes have been developed, especially according to different capacity ranges. The two predominant technologies among them are grate combustion and fluidized bed combustion. Over the last few years, the use of residual wood has proven to be most cost-effective among all available and legally permitted types of biomass. Further types of biomass, like renewable primary products for example, result in higher costs and prevent an economical operation. Beside the combustion of wooden biomass, the production of biodiesel is possible by certain separation processes, such as pressing or extraction of biomass types which contain oil and grease. In addition to biodiesel, the utilization of bioethanol is necessary to achive a share of 5.75 % of all petrol and diesel for transport purposes in 2010, like demanded by the European Union. To make the production of biofuels more attractive, biofuels have been exempted from the petroleum tax in Germany. Another conversion method of biomass into energy is the anaerobic degradation of organic substances, i.e. conversion in the absence of air. After the conversion a gaseous energy source is available which can be used in combustion engines for energy production. In Germany the power production by this method accounted for approximately 1.1 TWh in 2003. Nowadays, direct combustion as well as biofuels and biogas production are considered well-established and proven conversion processes. When compared to gas- or oil-fired plants, most biomass energy plants are characterised by higher investment and in most cases also higher operation costs, which can compensated particularly by low biomass costs, e.g. when using wood residues. To ensure the cost-effectiveness of future biomass projects compared to fossil fuels, it will be necessary to reduce biomass prices, for instance by improved cultivation methods, or to increase the prices for fossil fuels.