*5.2. Economical Assessment*

The key economic parameter for CCT integration is capture cost. The comparison of capture costs (Table 10) among assessed CCT systems states that the less expensive technology is PCC-A system. The difference is shown in the values of CAPEX, which for IGCC-CaL is higher by €167 million and in OPEX by €17 million annually. The main reason for this difference is that PCC-A does not require high technological adjustments when compared to the IGCC-CaL systems. The IGCC-CaL system requires an initial batch of lignite with higher quality for gasification process, therefore the technological components (such as boiler) would increase the initial CAPEX. Moreover, IGCC-CaL requires the construction of an additional segment with auxiliary systems of air separation unit that also increases the initial investment.

Another parameter—cost of electricity (COE)—is influenced by OPEX. The higher OPEX of the IGCC-CaL system increases the energy cost by €33/MWh in comparison with the PCC-A (Table 7). However, both case CCT studies are showing a higher COE per MWh in comparison with the actual market price of electricity (Table 6). That leads to the conclusion that both systems tailored for the current Czech conditions are currently not economically viable.


**Table 11.** Comparison of study results with several references; GWP/CC—global warming potential/climate change; TA/AP—terrestrial acidification/acidification

The economical assessment of this study is based on the comparison of the cost effectiveness of both CO2 capture systems with the reference energy units. The results are shown in Figure 3. The graph describes the rising trend of the price of CO2 allowance throughout the years 2015–2050. The analyzed CCTs have the potential to achieve cost-effectivity in comparison to the power plant without CCT in the observed time frame. The PCC-A would be cost-competitive in the case the carbon price would be lower than €22.5/tCO2 (for CCU case), or €26.3/tCO2 (for CCS case). The IGCC-CaL would be cost-effective in the condition that the carbon price increases up to €58.7/tCO2 (for CCU case) and €60.9/tCO2 (for CCS case). PCC-A could achieve cost-effectiveness with carbon price at €24.1/tCO2 or €20/tCO2 under the condition of total CAPEX reduction by 5% and 15%, respectively.

It is important to note that the capital investments are decreasing over time for CCT, and therefore, total CCT costs will gradually decrease (dashed green and red lines in Figure 5). These economic dynamics might be the subject of further comprehensive economic study on CCT.

It is assumed that the price of the CO2 allowance will continue to rise (dashed black line in Figure 3) in the current state of climate crisis and economy crisis. Therefore, the economic decision to invest into the CCT may be major but only in the first years (3–4 years of the CCT construction) but it will lead to cost savings after the payback period (six years according to Reference [4]), as opposed to dealing with the inflating price of CO2 allowance.

#### *5.3. Environmental and Economic Combination Score*

The decision-making process of the CCT integration into power units must be based on a complex assessment, where the environmental and economic scores combine. This combination can be done by simple multiplying the environmental score (sum of all normalized values) and values of OPEX or CAPEX. PCC-A in comparison with IGCC-CaL, has a worse environmental score (0.004) and lower OPEX (€123.06 million) and CAPEX values (€1.097 billion). The IGCC-CaL system has lower values for environmental score (0.0023) but higher values for OPEX (€140.3 million) and CAPEX (€1.2641 billion).

This decision conflict between environmental and economic performance can be resolved by the total product (multiplying the environmental score and CAPEX (or OPEX) value (Figure 4). If the total value is low, it leads to the conclusion that the combination of environmental and economic performance is more favorable for the chosen technology.

The product of environmental score by CAPEX and OPEX can be seen in Figure 6. The graph shows that the IGCC-CaL unit has a smaller total score for both CAPEX and OPEX combination with the environmental score. It concludes that even if the CAPEX and OPEX of IGCC are higher than in the PCC-A process, the environmental performance seems to lower the total combination score.

**Figure 6.** Product of environmental score by CAPEX and OPEX for pre-combustion CO2 capture integrated into the gasification combined cycle (IGCC-CaL) and post-combustion capture by adsorption of CO2 by activated carbon (PCC-A).
