## 3 Results and Discussion
### Load and Electricity Generation in July 2030  
Figure 6 is the projected net power load and net electricity generation for July 2030 in Croatia. The onshore wind capacity increases from 1200 MW in 2024 to 1500 MW in 2030 while the solar PV capacity increases from 200 MW in 2024 to 1500 MW in 2030. Following the expansion of the solar PV sector, the foreseen ratio between wind and solar PV capacity is \(P_{\text{wind}}/P_{\text{solar}}=1.0\). The electricity generation from solar PV in Figure 6 includes only utility-scale solar PV available to the public grid and excludes self-consumption. The CCGT capacity increases from 550 MW to 700 MW, after the addition of a new unit at the EL-TO Zagreb power plant [54]. The category of hydro reservoir will be expanded from 1700 MW to 2100 MW after the commissioning of the Senj 2 hydro power plant in 2028 [55]. The categories of hydro run-of-river, biomass, other renewables, nuclear, and hard coal are assumed unvaried since no new projects or retiments are expected till 2030. The production profiles of dispatchable energy sources are optimized, aiming to minimize import electricity but respecting the renewable energy availability and the technical limitations of the individual power plants. The projected load patterns in Figure 6 remain similar to the recorded patterns shown in Figure 4. The maximum projected load in July 2030 is 3660 MW and represents an 8.3% increase over the 3381 MW in July 2024. The total electricity demand increases by 5.9%, from 1806 GWh in July 2024 to 1913 GWh in July 2030, as predicted by Equations (12) and (13). Figure 7 shows how the expansion in the renewable energy sector could contribute to resolving the energy import dependency in the summer months. Solar PV production profiles fit well with the power load profile, especially in the morning and afternoon hours. However, solar PV production ceases at 19:30, while high demand persists till 23:00. Figure 6: Projected load and net electricity generation by source in July 2030 in Croatia, assuming increased electricity demand and expansion of the power plant portfolio. After 2030, the continued expansion of the solar PV sector will require additional dispatchable capacity, such as pumped hydro storage or battery energy storage systems. Surplus low-cost electricity generated during peak solar hours could be stored in pumped hydro facilities and dispatched later in the evening to meet demand. The analysis of the missing power generation in Figure 7 indicates that approximately 2 GWh of short-term energy storage, assuming a discharge capacity of 400 MW over 5 h, would be required to cover most of the evening peak demands. A future expansion of the Slovenian-Croatian jointly owned nuclear power plant at Krsko is also being discussed [56]. Investment costs are around 9000 \(\upell\)/kW, but nuclear energy is considered strategic to reduce the exposure to volatile fossil fuel prices, ensure long-term supply, and promote decarbonization in the power sector [57]. Table 1 compares the installed capacity and the net electricity generation by energy sources in July 2024 and July 2030. By 2030, the generation from solar PV in the summer months becomes comparable to reservoir hydro and onshore wind. Solar PV increases from 27 GWh to 250 GWh and onshore wind increases from 191 GWh to 277 GWh, while hydro reservoir expands from 249 GWh to 287 GWh. In 2030, the 1500 MW of solar PV will generate 1879 GWh of electricity, while the 1500 MW of onshore wind will generate 3807 GWh. The renewable share of demand (\(f_{\text{RES}}\)) increases from 38.8% in July 2024 up to 54.7% in July 2030. On the annual level, electricity generation from renewable energy increases from 53.8% in 2024 up to 66.9% in 2030. The increase in the renewable share is mostly attributed to the doubling of VRE electricity (\(f_{\text{VRE}}\)): from 15.6% up to 30.3%. The increase in VRE generation is even more pronounced in the summer months: from 12.1% in July 2024 up to 28.4% in July 2030.