Flex Fuel Polygeneration (FFPG) is the use of multiple primary energy sources for the production of multiple energy carriers to achieve increased market opportunities. FFPG allows energy supply adjustments to meet market fluctuations and increase resilience to contingencies such as weather disruptions, technological changes, and variations in supply of energy resources. As an example of FFPG, we explored natural gas and municipal solid waste as the primary energy sources converted into electricity and transportation fuels as the energy carriers through the processes of anaerobic digestion, FischerTropsch synthesis (FTS), and combined cycle power. We combined previous techno-economic analyses of conventional energy production plants to obtain equipment and operating costs, and then evaluated the economic performance of the FFPG plant designs. We investigated the effect of changing operating parameters on economic performance of the baseline FTS and FFPG systems. (C) 2016 Elsevier Ltd. All rights reserved.