## 4 Discussion  
The aim of this study is to build a hybrid plant consisting of geothermal, CST, and biomass that addresses the issues of GPPs. The energetic results show that, Issues 1 and 2 are addressed positively by this hybridization strategy as follows. Issue 1, _excess turbine capacity_ in GPPs stemming from decreasing geothermal brine enthalpy over the operating years, is addressed by using an additional steam flow obtained by utilizing heat from a CST-biomass hybrid topping cycle and resulting in an increase in the power output levels in the IPT and hence LPT. Moreover, Issue 2, the decreasing GPP performance during summer months, is addressed by increasing CST contributions during summer, when the solar resources peak. Furthermore, by adding biomass to the hybridization, the overall flexibility and dispatchability can be increased as it is possible to adjust the biomass combustion rate. There are two assumptions regarding the hybrid plant that should be clarified. The first is the WCT of KZD-2 is assumed to be operating under its maximum capacity since the GPP is under performing. Thus, it is also assumed that the water utilized from the WCT to be supplied as steam to the IPT does not cause any water balance issues in the overall power plant. The second is that the intermediate components in the power cycle are omitted for this work. This includes the demisting or a similar purifying system before the turbine inlets to reduce the moisture and the associated issues in the turbine blades. Although this element can alter the power and efficiency values, the effect is assumed to be minimal, as the main concern of this work is the overall performance results of the hybrid power plant. The energetic outputs show the synergistic combination of the three RE sources. OR shows an increase in utilization during winter (October to February), so its portion of power generation reaches 10 MW\({}_{\text{e}}\) levels day and night. During summer, however, as the OR becomes less available and solar becomes more available, the usage rate of OR decreases, and the power production from biomass becomes variable between 6 and 8 MW\({}_{\text{e}}\). During the day, the biomass consumption rate decreases as desired when CST is utilized more. Also, the results show that, in summer conditions with sunny and clear skies, it is possible to generate additional power of more than 20 MW\({}_{\text{e}}\) while also utilizing the excess turbine capacity in the IPT. During these times, the biomass combustion rate varies between 4.2 to 5.8 kg/s, depending on the season and available solar resources. In addition, as the excess turbine capacity in the IPT is used, the CF also increases. Previously, the CF of KZD-2 was approximately 69%. while with the added benefits of this hybridization, the CF increases to approximately 74%, considering the KZD-2 as a whole, and to approximately 76%, considering only the flash part of KZD-2. This increase in CF is important to utilize the installed capacity in the KZD-2 plant that is not in use. Economic analyses show that, with this hybridization, the LCOAE is 81.19 USD/MWh. For comparison, the YEKDEM incentive guarantees the purchase of energy from standalone GPPs at a rate of 105 USD/MWh and for standalone solar and biomass power plants at a rate of 133 USD/MWh [19]. Hence, the resulting LCOAE is promising for RE plants under the YEKDEM incentive. Moreover, this LCOAE is also a competitive value among other energy sources, such as residential and utility-scale PV and coal [36]. The payback period is considered for both YEKDEM and the spot market. With YEKDEM, the payback period is only five years, shorter than all standalone CST, geothermal, and biomass systems. On