Review of concepts for a demand-driven biogas supply for flexible power generation

The share of electricity produced from renewable energy is constantly increasing in Germany and worldwide. The transformation to an electricity system based on renewable sources is characterised by an increasing need for balancing power in order to compensate power supply from fluctuating sources, such as solar or wind. Biomass, more precisely energy from biogas, has the potential to generate electricity flexible on-demand. A demand-driven biogas production is vital for balancing power generation and can generally be achieved by biogas storing or flexible biogas production concepts. This study analyses and reviews both concepts regarding their ability to facilitate a biogas supply for short-term and long-term balancing power generation. Results show that a demand-driven biogas supply based on a biogas storing concept is, due to the fast availability of biogas (i.e. biomethane), suitable for the generation of positive secondary and tertiary balancing power. Whereas, long-term balancing power can be provided by flexible biogas production as well as by biomethane, which was injected and stored in the natural gas grid. Basically all reviewed biogas supply concepts that facilitate a shutdown of electricity generation by storing or stopping the biogas production can additionally provide negative balancing power. (C) 2013 Elsevier Ltd. All rights reserved.