Figure Real-time market energy price (red), hydrogen produced (blue) /released (yellow)/ stored (green), and the gas in the storage tank (grey) for the flexible electrification system. Panhandle, TX in Jan. 2020. Economic Viability. We considered a couple of operational modes (flexible and non-flexible) under a couple of electricity markets (RTM and DAM) and at a couple of geographical locations in Texas (Houston and Panhandle). As such, we use our computational framework to explore 8 possible scenarios. In Figure , we summarize the economic results for the 8 scenarios. The total annual cost (TAC) consists of annualized capital expenditure of hydrogen tank, electrolyzer stack and balance of plant (BOP), rWGS unit, electricity cost, CO2 purchase cost, and deionized water cost. We calculated the annualized capital investment by multiplying the capital cost of a piece of equipment with an annualized factor, which depends on the interest rate and the plant lifespan. The SI provides a comprehensive overview of the economic parameters involved. The cost of CO2 and deionized water purchases, on the other hand, is dependent on market prices of these commodities and the yearly consumption of CO2 and water by the facility. The price of CO2 varies based on its source, with CO2 from coal-fired power plants estimated at 47 USD per ton and CO2 from natural gas power plants estimated at 75 USD per ton . Obtaining CO2 from an ethanol fermentation plant is comparatively less expensive, with a CO2 price of around 30 USD per ton . In this study, we assumed that CO2 was obtained from a coal-fired power plant. A sensitivity analysis was carried out (see next section) to evaluate the impact of CO2 prices on overall economics.