## 9 Conclusions
The former are further divided between the costs for operating the cooling stations, line maintenance, and its dismantling. The capital costs are distinguished between the costs for purchasing the HTS tapes, insulating material, and cryostat, the cabling of all materials into the final architecture, the purchase of the cooling stations (distinguishing between the intermediate and termination ones, which are different sizes), the cable terminations, and the vacuum system. Here, the capital costs also included the purchase of land for underground line installation, the copper for the neutral layer conductor, and additional capital costs for the cable installations, their commissioning, and the costs referred to ancillary devices. These last cost indexes were not present in previous OSCaR versions. These terms, though not decisive for the specific cable configuration analyzed, could impact other designs which might be investigated in the future using OSCaR tool and are therefore included in this comprehensive document. Furthermore, other improvements of this version of the tool comprise the quantitative discounts applied to the capital costs for the selected cable system elements based, for example, on the quantity of superconducting tape required or the total number of cooling stations to be purchased. Moreover, the operating costs are computed by considering a time-varying power curve over a year (and therefore over the entire device lifespan), rather than assuming a constant maximum power. These approaches are expected to yield more accurate and realistic cable cost calculations. Additionally, the user-defined parameters necessary for calculation were updated for the HVAC cases compared with the previous medium-voltage case [36], enhancing the tool's relevance for high-voltage applications, such as the use of a more efficient insulating material, Tyvek PE, compared with the conventional PPLP. The effectiveness and versatility of the developed tool are demonstrated through relevant parametric analyses. The results of these analyses should be considered qualitative, providing general trends for relevant design parameters. Indeed, the values reported were heavily dependent on the user-defined parameters and the availability of reliable data. Users with different data sets can apply the comprehensive methodology outlined in this work to obtain more quantitative results tailored to their specific needs. As a first example, the model was applied to estimate the costs of superconducting cables for transmitting extremely high power values (between 1 GW and 3.5 GW) at a voltage of 220 kV, which was chosen as the upper limit for high-voltage applications, as analyzing extra-high voltage levels might not be ideal for maximizing the potential of the superconducting technology. These power levels, which are challenging for current networks, could become advantageous with future grid developments and increased localized electricity production and demand. In the parametric analysis of a 50 km line connected to load with a \(cos\varphi\) equal to 0.9, the overall cable system cost ranged from EUR 5.3 M/km for the 1 GW case to EUR 9.2 M/km for the 3.5 GW case. It can be concluded that single high-power cables are more cost-effective than installing multiple lower-power cables in parallel. However, these results do not account for the cost of some accessory components, such as transformers. The operating costs over the cable's lifespan (40 years) were limited to 15-16% of the total costs, primarily due to the operation of the cooling and pumping stations. These costs closely followed the trend of losses calculated based on the real-time varying power curve of the cable and not just its maximum power condition. Regarding the losses, those ones due to AC currents in the superconducting tapes and the thermal inputs entering the cryostat from outside were the most relevant ones. The capital costs mainly depended on the cost of the HTS tapes, the cabling process, the cryostat, and the civil engineering works for installation.