This study evaluates the energy and economic performance of small and medium size coal gasification power plants integrated with a syngas storage section (ICGSS). In ICGSS systems, a portion of the produced syngas is stored during periods of low energy demand and used to increase power output during periods of peaking demand, so that they can perform a load-following service and can operate in the electricity markets for energy and spinning reserve. The main energy and economic performance of ICGSS power generation plants were evaluated with reference to two different prime movers (gas turbines and internal combustion engines) and as a function of the required electrical load curve. Moreover, a preliminary economic analysis was also carried out to evaluate the peak-load energy production cost in comparison with base-load energy production cost. The results of the study show that ICGSS power plants offer considerable scope for enhancing operating flexibility and load modulation capabilities of coal gasification power plants. Plant options based on internal combustion engines performed better than options based on gas turbines. (C) 2011 Elsevier Ltd. All rights reserved.