Cost of small-scale dispatchable CO2 capture: techno-economic comparison and case study evaluation

Dispatchable power sources are crucial for electricity system stability and security of supply. Currently, the United Kingdom uses small-scale (<50 MWe) gas turbines to provide this function. To ensure we reach Net-Zero emissions by 2050, these small-scale dispatchable generators will require CO2 abatement; however, limited studies focus on these forms of power generation.

In this work, we use process models developed in our previous studies, to calculate the levelised cost of electricity (LCOE) for a small-scale gas turbine equipped with Carbon Capture and Storage (CCS). The results show that the inclusion of CCS for these dispatchable generators increases the LCOE from 172 £/MWh to 514 £/MWh, almost tripling the cost of electricity. This is due to economies of scale and the low capacity factor. As these generators operate for less than 20% of the year, the levelised cost is drastically higher than other forms of low-carbon power. Dispatchable power is usually more expensive due to the small plant size and transient operation, and including CCS exacerbates this issue. Future work should focus on alternative forms of CO2 capture (designed specifically for small-scale gas turbines) and different dispatchable power generation, i.e., hydrogen and energy storage.