Alternative energy storage for wind power: Coal plants with amine-based CCS

This paper analyses the performance of a hybrid system consisting of an existing coal plant with post-combustion amine based CCS with amine storage, and a co-located wind farm. The amine storage system allows storage of the CO2-rich amine solution to reduce the energy penalty of the CCS system at times of high electricity prices/high demand. The amine-rich solution can be regenerated at an enhanced rate when electricity prices are relatively low or when wind power output exceeds the transmission capacity of the connector lines: effectively providing 'storage' for wind power and a mechanism for muting the variability of wind power output. Using prices and wind data from the eastern region of U.S., we find the optimal configuration and operation, profits, Cost of CO2 Capture (CoC), and Levelized Cost of Electricity (LCOE) of the hybrid system, with and without constraints on the variability of the net power output. We find that favourable conditions regarding price arbitrage opportunities and wind power output variability -same or lower variability than that observed in ~70% of sites in the EWITS database- Allow the hybrid system to be more cost effective than other alternatives for reducing CO2 emissions from an existing coal-fired power plant and/or integrating wind power as a component of a base-load plant. For example, hybrid systems with up to 10% of the total installed capacity from the wind farm, can operate as a base-load plant, and still be more profitable and have lower LCOE and CoC values, than a continuously operating coal plant with a CCS retrofit. Using an existing plant as a component of a hybrid system can result in lower CoC than replacing it with a new Natural Gas Combined Cycle power plant -assuming natural gas prices are in the range 6-8 $/MMBtu.

Duke Scholars

Author Dalia Patino-Echeverri Environmental Sciences and Policy