Based on the structural theory of thermo-economics, a 600 MW unit was taken as an example. An integration system which uses fuel gas heat and solar energy as a heat source for post-combustion carbon capture was proposed. The physical structure sketch and productive structure sketch were drawn and a thermo-economics model and cost model based on the definition of fuel-product were established. The production relation between units was analyzed, and the composition and distribution of the exergy cost and thermo-economic cost of each unit were studied. Additionally, the influence of the fuel price and equipment investment cost of the thermo-economic cost for each product was studied. The results showed that the main factors affecting the unit cost are the fuel exergy cost, component exergy efficiency, and irreversible exergy cost of each unit, and the main factors affecting the thermo-economics cost are the specific irreversible exergy cost and investment exergy cost. The main factors affecting the thermal economics of solar energy collectors and low-pressure economizers are the invested exergy cost, negentropy exergy cost, and irreversible exergy cost of each unit.