*3.2. Determining Cost Estimations and Emissions for the Short-Term*

In this section, a cost and emission forecast for the period 2025–2035 will be given. First, it should be explained how the data were obtained. It is important to read Sections 2.2 and 2.3 first. Gilbarco Tritium RT175-S DCFC Fast Charge Single Electric Vehicle 175 kW Charging Stations have a list price of USD 105,000 each. For a charging station with double capacity, an investment of USD 175,000 is considered [23]. Costs for maintenance have not yet been released.

Capex and Opex of the Maeve Recharge 30-ft container with 8 MW battery capacity and control module have also not yet been released. The battery pack cost will be lower than the market price for new batteries because it is reused from electric aircraft. The final megawatt charging system (MCS) standard is expected to be published in 2024 [24,25].

For the ticket price calculation in the short-term scenario, the data and calculations in Section 2.3 were used as a base Then, using the flight distance, the information from RTHA and the composition of the current ticket price, the price of a passenger per km can be given. It is further assumed that fuel costs and landing fees account for 30% of the ticket price. Furthermore, three possible environmental price increases offered by Lufthansa [26,27] were included and applied to the ERJ 190 and B737. A number is given in the brackets after the respective conditions, indicating which scenarios were considered in the following tables. These three environmental price increases amount to:


In addition, an average inflation rate of 2.44% was assumed, which resulted over the last 50 years in Germany [28]. This inflation rate is also included in the ticket prices, to give a realistic estimate of the prices for different time horizons.

• 2.44% inflation rate in terms of 2040 → (4).

For the price comparison per ticket with the GENESIS flight, Scenario 2 was assumed in the short term. Therefore, this scenario is considered with 20% SAF fuel and is comparable with the HEA case study. The calculated costs for the short-distance flight are shown in Table 8, and the costs for the medium-distance flight are in Table 9. These calculations and data show that HEA ticket prices are somewhat higher than conventional ticket prices for typical mission flights such as to London. However, in the medium-term scenario, the ticket price for a flight with ICE + Battery HEA is 1.8 below the comparable ticket price with 20% SAF. The expected ticket price for design mission flights is 11.8% below the comparable price when using an HEA. As soon as HEA flights with PEMFC + Battery can be offered, the ticket price difference is considered very attractive purely on the basis considered: a price saving of 46.7% is expected for typical mission flights and 40.4% for design mission flights.

**Table 8.** Costs for typical mission flights, medium-term (2040) forecast.


**Table 9.** Costs for design mission flights, short-term (2040) forecast.


Table 10 shows an estimate of the ticket development for 2040, which can be derived using the presented method. This table illustrates very well the impact of inflation and the environmental bonus in the categories on different routes. According to this, the EIS of PEMFC + Battery HEA results in competitive ticket prices for HEA PEMFC tickets. The tickets for the flight to Pisa are 17% more expensive than the expected ticket prices without subsidy (4). As soon as customers want to fly with "80% climate project subsidy and 20% SAF fuel (2,4)", the ticket PEMFC HEA is already 4% cheaper. Nonetheless, it should always be mentioned that the calculation was made without the high investment research and operating costs.


**Table 10.** Ticket price forecast, 2040.

Nevertheless, the savings on the expected ticket price per passenger offer a first estimate to make these investments lucrative for airlines and to justify the initial investments with a long view into the future. This fact confirms the previously established thesis that HEA flights have the potential to be financially attractive and environmentally friendly.

Finally, the HEA flights' estimated emissions for the short-term scenario are given for an average day, month and year. The calculation basis was the methods described in Section 2.3. The results are presented in Table 11. The HEA produce daily emissions of almost 58 tonnes of CO2. Annual emissions of nearly 13 863.65 tonnes of CO2 are expected. The NOx values are 49.619 tonnes per year, whereas 20.04 tonnes of CO are expected to be emitted annually. The values were estimated according to the procedure presented in Section 2.3. These high emissions indicate the urgency of transitioning towards sustainable hybrid-electric aviation.

**Table 11.** Emissions forecast of HEA flights in the medium-term (2040) scenario.


For further classification and comparison purposes, a conventional aircraft from D1.2 [13] was used in Table 12. These flights were considered with kerosene only. By comparing the emissions of Tables 11 and 12, it can be deduced that, by flying with PEMFC + Battery HEA, 49.5% CO2, 51.1% NOx and 48% H2O saving can be achieved. Flying with a PEMFC + Battery HEA, 100% CO2, 100% NOx and 77.9% H2O savings can be achieved.


**Table 12.** Emissions of a comparable short-term conventional aircraft (with new gas turbine engines installed) in combination with flight schedule.
