## 4 Results and Discussion
### Gas Power Plants  
In the case of a gas power plant, water from the cooling tower can be used for the preliminary cooling of air. The unit cools the air, thereby increasing its density, allowing for a reduction in the energy consumption for the compression process or achieving higher power with the same fuel consumption. The performance of a gas turbine supplied with air pre-cooled using water from DPCT and WBCT is presented in Figure 9. The obtainable capacity vs. nominal capacity with an inlet air temperature equal to 15 \({}^{\circ}\)C is presented in Figure 9a,b; the difference in obtainable capacity using the example of 600 MW gas turbine is presented in Figure 9c,d; and the potential natural gas savings are presented in Figure 9e. Maintaining a lower temperature with DPCT allows lower air temperatures at the inlet to the turbine, which corresponds to better turbine performance. The dew-point tower allows it to generate from 2 to 10 percent more capacity than on outdoor air. The wet-bulb unit is able to provide a 0.2 to 5 percent point increase in capacity. A 600 MW turbine, on average, is able to produce 44 MW more power with DPCT (8% increase on average--Figure 9c) in comparison to operating on outdoor air and over 22 MW more in comparison to the operation with WBCT (4% increase on average--Figure 9d). In Polish climatic conditions, fuel savings or excess power can be up to 10% with DPCT and up to 5% with WBCT. It is worth emphasizing that the external temperature has less impact on the DPCT performance,  
Figure 8: Obtainable outlet water temperatures in Polish climate. (**a**) DPCT. (**b**) WBCT.  
allowing it to provide much more stable temperatures during the cooling season, which can contribute to an additional increase in the turbine performance [18]. The potential fuel savings for a 600 MW power plant based on gas turbines vary from 1200 m\({}^{3}\) per day to 2600 m\({}^{3}\) per day for WBCT and from 2500 m\({}^{3}\) per day to 5000 m\({}^{3}\)/day for WBCT. On average, the DPCT is able to save 3800 m\({}^{3}\) of natural gas per day, whereas the WBCT is able to provide 1820 m\({}^{3}\) of average gas savings. The cost of producing electricity from gas is approximately 160 EUR/MWh [19]. A 600 MW gas power plant would be able to save from 113 to 223 thousand EUR per day with the dew-point cooling tower and from 53 to 120 thousand EUR per day with WBCT. On average, the money savings per day would be 169 thousand EUR for DPCT and 81 thousand EUR for WBCT. Annually, the application of the dew-point cooling tower allows for 23,995,452 EUR savings, whereas the wet-bulb cooling tower allows for 11,479,039 EUR savings (the difference is 12,476,413 EUR in favor of the DPCT). It can be seen that the dew-point cooling tower is able to bring visible energy savings to a gas power plant in temperate climate conditions. The energy savings correspond to an appropriate level of money savings, which can be utilized for other purposes. It can also be seen that DPCT provides over two times more savings than the traditional solution, which shows that it has the potential to replace them in temperate climate.  
Figure 9: _Cont._