Techno-economic feasibility assessment of calcium looping combustion using commercial technology appraisal tools

Calcium looping combustion (CaLC) is a new class of low–CO ₂ –emission technologies for thermochemical conversion of carbonaceous fuels that can help achieve the emissions reduction targets set out in the Paris Agreement. Compared to mature CO ₂ capture technologies, which cause net efficiency penalties higher than 7% points, CaLC results in a net efficiency penalty of 2.9% points. However, a thorough economic assessment of CaLC needs to be undertaken to evaluate its economic viability. The levelised cost of electricity is commonly used to assess the economic performance of clean energy systems. However, this method does not account for commercially important parameters, such as tax, interest, and depreciation charges. This study aimed to improve the reliability and accuracy of economic assessments of clean energy systems by implementing the net present value (NPV) approach. This approach was applied to assess the economic performance of two concepts of the CaLC-based power plant with either the conventional steam cycle (SC) or the supercritical CO ₂ cycle (s-CO ₂ ) for heat utilisation along with the bottom-up approach to total capital cost estimation. A parametric study for both concepts was also conducted to assess the impact of the key thermodynamic parameters on the economic performance. Although the s-CO ₂ case with revised assumptions was shown to result in a 1%-point lower net efficiency compared to the SC case, its break-even cost of electricity was lower by 0.81 €/MWh. Further improvements of the techno-economic performance can be sought by optimisation of the s-CO ₂ cycle structure.