Time-Resolved Cost Analysis of Natural Gas Power Plant Conversion to Bioenergy with Carbon Capture and Storage to Support Net-Zero Emissions.

The ongoing construction of natural gas combined cycle (NGCC) power plants is incompatible with a transition to global net-zero greenhouse gas emissions. This work evaluates the emission pricing and technology costs required to convert an existing NGCC power plant to a biomethane-based bioenergy with carbon capture and storage (BECCS) system. The conversion was evaluated using techno-economic analysis and time-resolved life cycle assessment. At current technology costs, carbon dioxide equivalent emission prices of $142 and $215 per metric ton are required to allow a BECCS conversion to compete with normal operation or shutdown, respectively, of an existing NGCC power plant. These results show further technological development must occur in parallel with emission pricing to make BECCS viable. If mid-range emission pricing estimates are implemented ($25-$105 per metric ton), BECCS capital cost targets range from $1434 to $2098 per kW of capacity, while operational costs range from $32 to $51 per MWh of electricity produced to enable conversion. These findings indicate that operational costs associated with fuel consumption and production must be significantly reduced to make a BECCS conversion viable, even with emission pricing. All data and methods of this work have been made publicly available in an open-source model.