With the share of intermittent renewable energies within the electricity system rising, balancing services from dispatchable power plants are of increasing importance. Highlighting the importance of the need to keeping fuel costs for flexible power generation to a minimum, the study aims to identify favourable biogas plant configurations, supplying biogas on demand. A cost analysis of five configurations based on biogas storing and flexible biogas production concepts has been carried out. Results show that additional flexibility costs for a biogas supply of 8 h per day range between 2 is an element of and 11 is an element of MWh (1) and for a 72 h period without biogas demand from 9 is an element of to 19 is an element of MWh (1). While biogas storage concepts were identified as favourable short term supply configurations, flexible biogas production concepts profit from reduced storage requirements at plants with large biogas production capacities or for periods of several hours without biogas demand. (C) 2014 Elsevier Ltd. All rights reserved.