Preparing Your Airport for Electric Aircraft and Hydrogen Technologies (2022)

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27   C H A P T E R   4 4.1 Electric Propulsion System Application The electric and hybrid-electric approaches of electric propulsion allow manufacturers to take on different operational use cases. The electric aircraft and electric propulsion technologies under development broadly apply to five primary aviation use cases: regional aviation, com- muter aircraft, light air cargo operations, flight training, and personal use general aviation. Regional Aviation Regional flights are currently performed by small jet or turboprop aircraft. On most markets, they are used for passenger-carrying and belly cargo purposes, typically having between 15 and 100 seats. Flight operations for aircraft in this class are typically less than 2 hours, cov- ering an average of 330 nautical miles (NM). Aircraft designs in this category include the Faradair Aerospace BEHA, Heart Aerospace ES-19, and United Technologies Corporation (UTC) Project 804. Commuter Aircraft Aircraft in this class conduct passenger-carrying operations under the FAA’s Part 135, which allows them to provide unscheduled flight services, such as air taxis and charters, as well as limited scheduled operations. Aircraft typically carry 2 to 20 passengers and use both piston and turboprop propulsion systems that produce between 250 and 1,500 kW of power. These aircraft fill the roles of commercial intercity transport and business aviation, with flights averaging 117 NM (135 statute miles) and lasting less than 1 hour. Designs are under devel- opment for both fully electric and hybrid-electric aircraft. Programs in this category include the Ampaire Electric EEL, Bye Aerospace eFlyer 800, Eviation Alice, magniX eCaravan, and Tecnam P-Volt. Light Air Cargo/Mail This class of aircraft is used for the transport of light freight and parcels over an average distance of 125 miles. Flights usually take less than an hour. This group encompasses aircraft with cargo capacities up to around 7,500 pounds and that leverage both piston and turbo- prop propulsion to provide between 200 and 2,000 kW of power. Operations include services between cargo hub airports and smaller aviation facilities, as well as freight deliveries between rural areas; remote communities; and islands such as Alaska, Hawaii, and the U.S. Pacific Trust Territories. This class of aircraft could comprise most of the small passenger commuter aircraft mentioned above. Market Assessment

28 Preparing Your Airport for Electric Aircraft and Hydrogen Technologies Flight Training Pilot training aircraft typically share three primary characteristics: cheap to acquire and operate, reliable, and easy to fly. These aircraft typically use piston engines, producing between 100 and 200 kW, and accommodate 1 to 3 passengers for roughly a couple of hours of flight time. These aircraft tend to have high utilization for aircraft of their size, averaging around 400 flight hours per year. Ongoing projects encompass both designs of new aircraft and the adaptation of existing airframes. The Bye Aerospace eFlyer 2 is an example of electric training aircraft. Personal-Use General Aviation Aircraft in this class are primarily used for private flight activities, and they do not involve the commercial transportation of passengers or cargo. Aircraft of this class typically carry 1 to 9 passengers. Today, they are primarily powered by piston or turboprop engines that provide between 100 and 300 kW of power. Utilization is much lower for personal-use aircraft, which average around 72 flight hours per year. Some OEMs are developing electric and hybrid-electric variants of existing aircraft, such as Pipistrel’s fully electric Alpha Electro. Other companies have entered the market as well, including Bye Aerospace with its two- and four-seat variants of the eFlyer. 4.2 Market Assessment Electric aviation is still nascent, with over 10 concepts across phases of design and develop- ment. The FAA’s revision of Title 14 Code of Federal Regulations (CFR) Part 23 certification requirements for normal category airplanes opened the door for smaller electric aircraft. How- ever, no OEM has yet completed the certification process for electric aircraft in the United States. In contrast, for larger commercial aircraft, certification pathways for electrification do not yet exist, because 14 CFR Part 25 on transport category airplanes does not currently cover electric propulsion. Given these fundamentals, airport practitioners can see this future market through the following three adoption scenarios. Baseline: Mild Savings, Tech on Schedule, Conversion Market The baseline scenario predicts an active fleet of more than 3,500 electric aircraft operating across the NAS by 2030, producing a $900 million market across manufacturing, maintenance, fleet operations, and infrastructure development. This outcome is based largely on the following driving variables: operating costs, certification timeline, technology development, and fleet operator incentives. Market size results and discussion are as follows: • Lower operating costs: Both fully electric and hybrid-electric aircraft are expected to have lower operating costs than comparable aircraft powered with conventional “thermal” engines. Reduced maintenance costs and decreased fuel costs should provide financial benefits for flight operators. Lower overhead costs will lead operators to consider increasing the utilization of electric aircraft. • Timely certification: This scenario assumes that the first certification of an electrically powered aircraft under 14 CFR Part 23 will occur in 2021 and that numerous aircraft platforms will have followed by 2025. Later in the 2020s, additional standards work from industry and regu- latory stakeholders could amend 14 CFR Part 25 standards to cover electric propulsion, paving the way for certification of the first electric commercial airline aircraft. • Technology development proceeds as predicted by industry: Development of electric motor technology will proceed with high-powered 1+ megawatt (MW) electric motors and

Market Assessment 29   hybrid-electric propulsion systems in development and expected to enter the commercial market by 2029. Additionally, advances in battery charging technology, led by a significant build-out in the automotive industry, will lead to cost reductions on the order of $100 per kW. • Certification of electric propulsion systems (independently of aircraft) will lead to the creation of a secondary market for converting conventional aircraft: Given the significant investment necessary for conversion assumed in the baseline, fleet operators have only a modest incentive to drive electrification across the fleet. Fleets with a higher remaining service life (“young fleets”) may see early adoption, while aging fleets may adopt a “wait-and-see” attitude toward conversion. General aviation may account for a larger portion of the conver- sion market than other aircraft use cases, primarily due to larger active fleet size with a newer fleet mix. Upside: Lower Costs, Mature Tech, and Rapid Certification In this more bullish market view (high scenario), operating costs fall further, aircraft certifica- tion timelines pull to the left, and rapid advances in applicable technologies result in increased adoption rates across use cases. The end result is nearly a doubling in total market size and active electric aircraft over the baseline scenario. • Significant reduction in operating costs: In this scenario, operating costs for hybrid- and fully electric aircraft undercut that of conventional aircraft by between 30 and 50 percent. The significant opportunity for savings leads to increased adoption rates across the use cases. Fleet operators are expected to increase utilization rates beyond that of the base case to maxi- mize revenue. Additionally, commuter service providers lower their fares, which results in an increased load factor. • Rapid certification of commercial airline platforms: This scenario supposes that, while cer- tification of Part 23 aircraft follows the same timeline as the base case, regulators, industry, and standards organizations collectively work to enact rewrites of 14 CFR Part 25 and enable certification of fully electric and hybrid-electric large commercial aircraft by 2025. • Accelerated technology development: This use case proposes that rapid and high-impact breakthroughs accelerate electric propulsion research and development beyond the time- line predicted by the industry. Development areas include electric and hybrid-electric motor technology, battery design, and fast charger technology. These advances, bringing high-power electric propulsion technologies to market in 2025, reduce the per kW-cost of charging a system by almost $200, and enable high-energy density batteries that increase the effective payload of electric aircraft. Downside: Higher Costs, Delayed Tech, Little Infrastructure In this bearish scenario for airport planners that represents the lower boundary of electric aircraft (low scenario), the initial introduction of platforms will be delayed by 3 to 5 years across the use cases, primarily due to the following: • Total cost of ownership remains higher than anticipated: In this outcome, maintenance and operating costs for electric aircraft are marginally lower than those of conventional air- craft. However, modest savings from operational benefits—primarily fuel and maintenance— do not justify investments needed to drive an uptick in aircraft purchases or at-scale conversion. By adding new cost factors, such as additional training for mechanics and warehousing additional parts, the operational savings do not offset the upfront investments, posing economic limitations to the introduction of electric aircraft into the current fleet. • Delays in certification: In this scenario, the first 14 CFR Part 23 electric aircraft certifications are delayed due to unforeseen challenges or events such as resistance from regulatory bodies,

30 Preparing Your Airport for Electric Aircraft and Hydrogen Technologies design alterations, or safety events involving electric aircraft. And, as such, the first electric aircraft certification is not completed before 2025, delaying widespread certifications until 2027. That said, 14 CFR Part 25 certifications of electric aircraft do not occur before 2030. • Stagnant technology development: Electric motor development activities do not produce 1+ MW motors before 2030, limiting aircraft size and therefore carrying capacity to 10 to 13 passengers or 6,000 to 8,000 pounds. As a result, larger passenger electric aircraft in the 40- to 90-passenger range come to the market beyond the 2025 to 2030 window. Similarly, battery technology research does not progress past its current state and does not enable increased usable payloads. While battery charging technologies will make modest techno- logical advances, these will not make an appreciable impact on the cost per kW. • Lack of widespread and reliable charging or hydrogen infrastructure drives up ownership costs and limits the geography of operations: Airports are not widely accessible to electric aircraft due to the lack of charging or hydrogen infrastructure. This places downward pressure on initial adoption as the availability of charging facilities directly determines viable bases and destinations. Scaling charging infrastructure is highly sensitive to installation and per-unit charger costs, as well as intermodal integration with existing municipal, airport power grids, and supply chains. 4.3 Infrastructure Development Market Assessment Infrastructure Developers At most domestic airports, electric aircraft will be able to make use of existing runways, hangars, terminals, and gates. As a result, open infrastructure needs will likely center on developing new battery charging systems. The market size of charging infrastructure is determined by anticipated fleet size, number of chargers required, charger capacity, and charger cost. In assessing these factors, the model makes a number of assumptions. Charger Capacity For each use case, the list below shows the required charger capacity factors in estimated power consumption during a typical flight and an assumed target charging time, based on oper- ational tempo. Due to the range of aircraft battery capacity, charging times and required capacity will vary between specific airframes: • Turboprop Airliner requires the highest total charging capacity at around 1,300 kW based on a targeted 30-minute charge time. • Commuter Aircraft require an average charger size of 850 kW based on an estimated 30-minute charging target. • Light Air Cargo, although similar in size to commuter aircraft, requires an average charger size of 150 to 200 kW as the targeted charge time is 3–4 hours. • Flight Training aircraft required the lowest average charging capacity at 75 kW, assuming a 1-hour charging time. • General Aviation required an average of 100 kW of charging capacity based on a 1-hour charge time. Charger Cost Charger cost estimates are based on current and forecast costs for 120 kW automotive direct current (DC) fast chargers. The model assumes that installation costs are fixed and are factored into the calculated per kW cost. For all five use cases, the baseline charger cost is $464 per kW, the upside is $395, and the downside is $553.

Market Assessment 31   Number of Chargers The number of chargers necessary to support electric aircraft operations is expressed by an estimated number of chargers required per aircraft. This number is based on assumptions about the expected pace of operations, target charging times, and the density of operations. • Turboprop Airline will require an estimated three chargers for every four aircraft due to the expected high pace and relatively concentrated pace of operations. • Commuter Aircraft will require an estimated one charger for every two aircraft. While these aircraft will expect a high tempo of operations, the high number of potential destinations thins traffic and will reduce charger demand at a given time. • Light Air Cargo will require an estimated one charger for every five aircraft. This number is due to the relatively low pace of operations, long charge times, and the large number of destinations served. • Flight Training also requires one charger for every two aircraft. This number is based on an operational cadence of four times 1-hour flights, with 1-hour charging cycles during an 8-hour operating day. • General Aviation has the lowest charging needs with only one charger for every 10 aircraft. Most airports experience relatively low general aviation traffic, there is typically little urgency of operations, and most charging for general aviation aircraft will be conducted at low power over long periods of time. Market Size in 2025: Discussion Table 6 displays the infrastructure developer market segment projections for each use case in the 2025 and 2030 time period. In 2025, the commuter aircraft use is predicted to make up the largest portion of the market across the three scenarios, followed by general aviation, flight training, and turboprop airliner. The infrastructure developer market supporting the commuter aircraft use case is the largest in 2025 at $10 million in the baseline and $14 million in the upside. This market size is likely due to the relatively high power and cost necessary for commuter aircraft charging equipment. This model assumes that operators will choose to leverage charging technology. However, the high cost may drive some to perform battery swap overcharging. General aviation is the next largest component of the market. It represents $0.2 million on the downside, $6.6 million on the baseline, and $11.1 million on the upside. While nascent, a gen- eral aviation infrastructure market may emerge in the downside scenario as general aviation is expected to be an early adopter of electric aircraft. Because the chargers necessary to support electric general aviation aircraft will likely be lower in cost than other use cases, the volume will be the primary driver for market size. While requiring a few fast-on per aircraft basis, the large number and likely geographic diversity of active electric general aviation aircraft will drive the early market. 2025 2030 Use case Downside Baseline Upside Downside Baseline Upside Turboprop Airliner 0.0 0.0 1.7 0.0 9.1 25.7 Commuter Aircraft 0.0 10.1 13.8 2.7 43.0 55.2 Light Air Cargo 0.0 0.3 0.3 0.0 0.7 0.8 Flight Training 0.0 2.5 5.6 0.9 3.1 6.8 General Aviation 0.2 6.6 11.1 4.5 34.1 58.4 Table 6. Infrastructure developer market size ($ million, 2020).

32 Preparing Your Airport for Electric Aircraft and Hydrogen Technologies The flight training use case represents $2.5 million on the baseline and $5.6 million on the upside. While requiring more chargers per aircraft than the general aviation use case, flight training operations charges have lower power requirements and therefore lower cost. Additionally, flight training operations will likely be more concentrated than general aviation. In 2025, the turboprop airliner use case will likely not emerge in the downside or baseline scenarios due to technology and certification delays preventing the integration of hybrid aircraft. The upside market size, $1.7 million, is predicted to be small due to the slow initial adoption of hybrid-electric aircraft. As with the commuter aircraft use case, fleet operators may choose to use battery swap overcharging to reduce operating costs. Light air cargo is expected to make up the smallest portion of the market representing $0.3 million in both the baseline and upside scenarios. The size of this market is largely attributed to slow initial adoption by fleet operators and the limited number of routes electrified. Market Size in 2030: Discussion In 2030, commuter aircraft will remain the largest portion of the electric infrastructure market, growing by an estimated factor of 5 in the baseline and upside scenarios. The market size predic- tions are $2.7 million on the downside, $43 million on the baseline, and $55.2 million on the upside. This market size will likely be the effect of operators increasing the number of electri- fied flight routes as larger portions of the active fleet are converted to electric propulsion, and advancing technologies that lead to increased aircraft capabilities. General aviation continues to represent the second-largest portion of the market in 2030, and it is estimated at $4.5 million on the downside, $34 million on the baseline, and $58 million on the upside. Growth in the active fleet size is the primary driver in the estimated five-fold increase in market size. Added factors include an increasing number of owners desiring private charging facilities and airports serving general aviation operations identifying the value of readily available fast-charging capabilities. In 2030, the implementation of hybrid turboprop airliners projects to grow the baseline sig- nificantly to $9.1 million and increase the upside nearly twenty-fold to $25.7 million. With the expected growth of the electric fleet size between 2025 and 2030, high charger costs will drive the market size. The flight training infrastructure market is expected to see limited growth between 2025 and 2030 across the scenarios and represent $0.9 million on the downside, $3.1 million on the baseline, and $6.8 million on the upside. The modest growth will be due to similarly modest growth in air- craft fleet size and the fact that operators with partially electric fleets will require less investment in infrastructure as they add more electric aircraft. As in 2025, the 2030 light air cargo market will represent the smallest portion of the electric infrastructure market at $0.7 million on the baseline and $0.8 million on the upside. Growth will be driven by operators increasing the number of electrified flight routes. However, the small airport size and remoteness of operations will likely limit the economic viability of many destinations. Note: Section 4.3 of this market assessment does not consider hydrogen technologies. 4.4 Drivers of Electric Market Demand (Discussion) As the literature on electric aircraft expands, U.S. airport practitioners will benefit from understanding the primary drivers of demand for that market: what will motivate airlines and excite passengers to adopt these new aircraft, and what might dim enthusiasm? At its core, the

Market Assessment 33   development and introduction of electric aircraft for commercial aviation requires a business case to support and drive operator investment. The rate of adoption for all five electric aircraft use cases hinges on reductions in the total cost of ownership over aircraft lifecycle and changes in federal incentives and public support for lower carbon emissions. Major Variable: Lifecycle Cost Reductions A primary pillar of the business case for electrically powered aircraft is the potential for opera- tional savings by minimizing the variable costs historically tied to aviation operations. Electric aircraft cost reductions are primarily due to decreased maintenance requirements, increased energy efficiency, and lower energy costs. Electric aviation propulsion systems are expected to be considerably more reliable than tur- bines or piston engines of similar power. Reliability of propulsion is usually tied to the com- plexity inherent in engine designs: the more parts operating in very tight sensitivity ranges, the greater the risk of failure. Because electric motor designs would eliminate hundreds or thousands of parts (e.g., rotors, stators, and fuel injectors) compared to conventional engine designs, scheduled maintenance and overhaul activities will require significantly less time and expense. For the Alpha Electro, Pipistrel recommends a motor overhaul every 2,000 flight hours, which costs around $1,000 and requires 12 hours of labor. In comparison, while conventional engine manu- facturers recommend an overhaul every 2,000 flight hours for piston engines and up to as many as 6,000 flight hours for a turboprop, significantly higher costs and timeframes are required for maintenance and overhaul. A piston-engine overhaul can cost upward of $20,000 while turbo- prop overhauls range from around $205,000 for commuter aircraft platforms (e.g., Cessna 208 P&W PT6A) to over $800,000 for turboprop airliners (e.g., ATR-72 P&W PW127B). Energy efficiency is another key draw of electric aircraft propulsion. In commercial aerospace, efficiency is the effectiveness at which a propulsion system converts the chemical, or electrical, energy in fuel into thrust. A fully electric, battery-powered propulsion system can achieve an overall efficiency up to 73 percent after the controller, motors, gearbox, and propeller losses. Conversely, a typical conventionally powered system can expect, at best, 40 percent efficiency in turboprops and an even lower 28 percent efficiency in piston engines. Higher efficiency means that less power, and therefore money, is used during operations. Fuel costs can account for 20 percent of airline operating costs, and a doubling in energy efficiency could prove decisive in airline economics—and significantly drive adoption rate. Beyond the increased energy efficiency of electric propulsion—in both hybrid and fully electric models—such aircraft provide cost-savings opportunities because electricity is cheaper than aviation fuel. Industry members believe that hybrid propulsion systems, intended for use on 40- to 90-seat turboprop aircraft, may reduce fuel consumption by up to 30 percent over conven- tionally powered aircraft by reducing engine power and providing supplemental thrust during takeoff with electric motors. On a 380-mile flight, an ATR 72 will burn around $800 worth of fuel. Hybrid-electric propulsion can potentially reduce that cost by $240 while replacing expended electricity, assuming charging on the ground, will cost only $80. With fully electric models, where no fuel is required, the cost reduction benefit is even higher. Pipistrel estimated that its Alpha Electro trainer costs only $3 per flight hour in electricity while a similarly sized and equipped conventional aircraft like the Cessna 152 incur fuel costs around $30 per flight hour. Major Variable: Emissions and Sustainability Aviation operations currently account for over 2 percent of the global human-produced carbon dioxide (CO2) emissions and 12 percent of emissions from transportation. However,

34 Preparing Your Airport for Electric Aircraft and Hydrogen Technologies aviation emissions are projected to grow by 3 to 4 percent per year—at a rate faster than popula- tion growth—and as governments and technology drive down emissions from other sources, aviation could increase its share of global emissions by 300 to 700 percent by 2050. As a result, several influential international institutions and initiatives such as the International Civil Aviation Organization (ICAO), Advisory Council for Aeronautics Research in Europe (ACARE), the European Commission, and the Clean Sky Joint Undertaking have developed programs, such as the European Commission’s Flight Path 2050 intended to build on current programs for responsible growth—balancing both the significant socioeconomic benefits of mobility with a responsibility to manage aviation emissions. Industry observers are considering potential parallels in the automotive sector, where many countries have enacted “carrot-and-stick” legislation to incentivize consumer adoption with tax breaks and limit automotive CO2 emissions with tiered penalties. While emission standards exist for aviation gas-turbine engines to curtail the venting of pollutants such as raw fuel, smoke, carbon monoxide (CO), and nitrogen oxides (NOx), aviation GHG emissions remain largely unregulated in the United States. However, in May of 2019, the U.S. Environmental Protection Agency (EPA) announced plans to issue standards that would, at a minimum, meet the proposed ICAO requirements to reduce CO2 emissions by 4 percent over 12 years. While groundbreaking for aviation, environmentalists view ICAO standards as too lenient. Public call for change could lead to regulatory tightening in the near future. Strict measurement and management of emis- sions may press fleet operators to consider alternative technology. Further, fleet operators may identify the value and potential competitive edge of establishing a reputation for being “green” conscious among potential consumers. Flight service providers (FSPs) must carefully consider this customer’s willingness to pay when setting ticket prices. In addition to reduced emissions, an expected benefit of electric aircraft propulsion is reduced noise pollution. While current literature provides little in the way of quantitative predictions as to the extent of this improvement, it is likely to be significant enough that current aviation noise regulations and restrictions will have little to no impact on electric aircraft operations. A potentially more substantial benefit of reduced aviation noise is the reduction of “unwanted sound” in communities near airports. Aircraft noise can have detrimental effects on surrounding communities, including general annoyance, sleep disruption, adverse impact on the academic performance of children, and increased risk of cardiovascular disease in people living in the vicinity of airports. The current FAA standard for acceptable noise pollution is 65 DNL or Day- Night Average Sound Level. Locations affected by levels higher than this are eligible for aid with noise abatement. Electric aircraft present an opportunity to reduce airport operational noise levels without impacting air traffic and increase the social acceptance of urban and suburban aviation activities. Major Variable: Technological Drivers The potential socioeconomic benefits presented by electric aircraft hinge on the assump- tion that electric platforms will be capable of meeting the mission requirements of each use case. The primary driving technologies behind electric aircraft performance are batteries and electric motors. Across the industry, the key measures of a battery system’s capabilities are energy density and effective cycle life. Battery developers seek to maximize both of these metrics to produce high-power, lightweight, and long-lasting batteries. Energy density is of particular importance in the commuter aircraft and light air cargo use cases where developers must strike a balance between range and payload. At the current energy densities, conversion developers magniX and Ampaire can only achieve ranges around 100 miles while maintaining aircraft payload. Such

Market Assessment 35   range restrictions greatly limit aircraft utility and flexibility and would likely depress demand. Battery energy density will likely also be a factor in the design of hybrid-electric propulsion systems for the turboprop airliner use case. Industry members claim that hybrid propulsion will reduce fuel burn by 30 percent while cutting aircraft range by only 40 percent, leaving an effec- tive range between 500 and 1,000 miles depending on the aircraft. This is significantly more than required for the majority of regional flights, which average 1 hour and approximately 250 miles. Improving battery energy densities will benefit hybrid-electric turboprop operation by pro- viding further reductions in fuel burn, and potentially increasing operational range. The second key measure of a battery system’s ability is its effective cycle life. Cycle life is the number of times a battery can be fully discharged and recharged before its capacity drops below a threshold, defined by the manufacturer, and must be replaced. It is a significant factor across all of the use cases because battery replacement will likely make up a major portion of maintenance costs. Pipistrel estimates that the batteries for its Alpha Electro can undergo 300 to 700 cycles before replacement, which costs between $13,000 and $20,000 and represents a significant portion of the estimated hourly operating costs. While it is likely that operators will take steps to maximize battery life through proper handling, improving battery cycle life will increase the attraction of electric aircraft. Battery technologies are currently improving at a significant rate, with one venture, Innolith, claiming to have developed a 1,000 Wh/kg battery that could be commercially available by 2022. This represents more than a factor three improvement from current densities and would greatly increase the potential draw of electric aviation to fleet operators. From the perspective of battery cycle life, the automotive industry is a driving force in the development and improvement of bat- tery technologies and approaches to maximizing effective life. Using techniques such as battery buffering, where vehicle systems will not allow operators to fully drain a battery, manufacturers have developed systems that allow for thousands of charge cycles before major degradation occurs. Leveraging these approaches, electric aircraft manufacturers can increase battery cycle life and maximize the economic benefits of going electric. 4.5 Projected Barriers to Electrification (Discussion) As a balance to the economic and ecological benefits presented by electric aviation, a business case must consider the potential drawbacks and barriers that must be overcome before achieving economically effective implementation. Understanding these challenges will be key to airport planners as they assess how electric aviation may impact their plans in the years to come. These barriers primarily center on aircraft technology, certification policy, and infrastructure. Major Barrier: Electric Aircraft Battery, Motor, and Electronics Technologies Energy storage is a key component in any aircraft propulsion system. For electric and hybrid aircraft designs, energy storage is entirely or partially enabled by battery packs, where current challenges center on energy density and battery safety and reliability. While current battery technology can potentially support much of the short-range portion oper- ations across all five use cases, energy densities are at a level where significant mass is required to store the necessary energy. The Eviation Alice requires an estimated 8,000 pounds of batteries to enable its 600-mile range. Comparable conventional aircraft require roughly one-fourth of that weight in fuel to achieve twice the range. This drawback will likely have a significant effect on the potential business cases for light air cargo, commuter aircraft, and turboprop airliner use cases, where reduced capacity leads to lower revenue. As battery technologies and available

36 Preparing Your Airport for Electric Aircraft and Hydrogen Technologies energy densities improve, aircraft range and payload economics will be revised. It is widely accepted in the industry that 500 Wh/kg is the minimum energy density required to achieve commercially acceptable load and range characteristics. The second challenge for electric aircraft battery technology is safety and reliability. Aircraft manufacturers and fleet operators have long experience managing the safety challenges pre- sented by fuel-based propulsion, and safety regulations and technology are well established. While batteries are also a recognized safety hazard in aviation, the industry has much less experience managing the risks and failure modes of batteries such as thermal runaway leading to combustion, toxic gas emission, and high voltage short circuits. Battery durability, particularly in the event of a crash, is another potential safety risk, and, because no aircraft with large battery packs has faced a crash to date, uncertainty in this area is high. Understanding the safety implications that electric aviation may present to airport operations is key as industry and regulators work to develop methods of safely preventing or managing these risks. An additional technology challenge faced by electric aircraft designers is developing high- power and low-weight electric motors and power management systems. Current electric motor technology has achieved approximately 750 kW motors and is capable of supporting opera- tions for the majority of the examined use cases. However, turboprop airliners and some light air cargo vehicles are anticipated to require 1+MW motors. In addition to developing the motors, developers of electric propulsion systems must design lightweight power electronics, such as inverters, rectifiers, and controllers, capable of efficiently converting and managing the high-power levels necessary. A primary challenge for these technologies is heat management. In conventional turbine engines, the majority of waste heat is exhausted from the engine to the surrounding air. Electric propulsion requires cooling systems to dissipate heat buildup before performance is affected. Until these technologies are developed, electric aircraft operations will likely be limited to small (13 passengers) platforms. Major Barrier: Aircraft Certification and Development of Favorable Regulatory Policies As with all technology developed in the aviation field, electric aircraft technologies will require regulatory backing before introduction to the market. New airframe designs and electric propul- sion systems will require airworthiness certifications and regulator acceptance for their support technologies such as high-power batteries and power electronics. The rewrite of 14 CFR Part 23 opened the door to electrically propelled aircraft by implementing performance-based rather than prescriptive standards. Most electric aircraft in the general aviation, commuter aircraft, light air cargo, and flight training use cases will be certified under this part as it encompasses smaller aircraft up to 19,000 pounds and carrying 19 passengers or less. While no electric aircraft has fully completed the certification process under Part 23, there are several companies currently involved in the necessary testing operations. These companies are developing a certification pathway that can be followed to streamline the process for future electric aircraft developers. Turboprop airliners are a notable exception. They will require certification under 14 CFR Part 25 for transport class aircraft. In their current state, 14 CFR Part 25 standards are prescrip- tive and do not enable pathways to certification for hybrid- or fully-electric aircraft. Developing and implementing a rewrite of 14 CFR Part 25 will likely be an extremely lengthy and expensive process. The rewrites of 14 CFR Part 23 took nearly 7 years from when the FAA chartered an Advisory and Rulemaking Committee to final implementation. A rewrite of 14 CFR Part 25 will likely face greater scrutiny and possibly wider resistance as it governs standards for commercial passenger-carrying aircraft. Ensuring operational safety will be paramount. The status of 14 CFR Part 25 certification standards will primarily impact the turboprop airliner use case.

Market Assessment 37   Major Barrier: Deployment and Cost of Developing Electric and Hydrogen Infrastructure Supporting infrastructure is key to enabling electric aircraft operations in today’s airport environment. Challenges to implementation of electric aircraft primarily center on meeting aircraft charging needs with appropriately powered battery charging systems and the supporting power infrastructure, as well as options for hydrogen supply for aircraft equipped with fuel cells. Because aircraft battery sizes, power expenditure, and required charging time vary between the use cases, the charger size necessary to support these operations varies as well. General aviation aircraft for personal use will likely require the least supporting infrastructure due to the low average annual utilization and the short average flight length of 45 minutes. This use case is not expected to demand fast-charging capabilities, and charging will require a rela- tively low power level of 10 kW, which can be easily supported by today’s technology. Flight training aircraft will have slightly higher charging infrastructure requirements than general aviation. Due to the much higher pace of operations typical of pilot training schools, fast charging—less than 1 hour per charge—capabilities will be necessary. However, because these aircraft are expected to have relatively small battery capacities—approximately 21 kWh— required charger power levels will be around 20 kW. This, like general aviation chargers, falls well within the capabilities of modern charging technologies. The light air cargo use case represents a step up in the charging infrastructure requirements. The low operational tempo expected for light air cargo will allow for long charging times of 3 to 4 hours. However, aircraft sizes will require higher power propulsion and larger battery packs to support average operations. Therefore, relatively high-power—about 200 kW—charging will still be necessary. This is on the higher end of consumer electric vehicle charging capabilities but well within the capabilities of commercial systems. Charger requirements to support commuter aircraft operations present the first significant infrastructure challenge. As fleet operations look to maximize aircraft utilization, turnaround time, and therefore available charging time, is expected to be low, between 15 and 25 minutes. Charger power levels necessary to allow this turnaround time are extremely high (i.e., 600+ kW). Chargers of this power level have been developed for charging buses and other heavy equip- ment. The installation and the maintenance of the charging infrastructure could be funded by airport operators, flight operators, FBOs, specialized third parties, and other tenants (e.g., flight schools). Also, similarly to Tesla in the domain of ground electric vehicles, OEMs may invest in the charging infrastructure to ensure accessibility of their aircraft to the regional and national aviation systems. As a potential alternative, operators may choose instead to leverage battery swap approaches, which would require operators to obtain equipment and facilities to transport, store, and charge spare battery packs. Idle battery packs will likely be charged at lower power over the course of a full day, requiring only low-power chargers—in the range of 60 kW. The adoption of battery swap is largely dependent on the categorization of this change by the FAA. If battery swap is considered as a major alteration per 14 CFR Part 43, requirements will be more stringent, making this operation potentially longer and more expensive. Electric turboprop airliners will likely present the most significant challenge to charging infrastructure and technology. Operations will likely call for rapid aircraft turnaround time as operators aim to minimize aircraft downtime. The small charging window will require very high-power charging capabilities—1 MW or more—that is on the cutting edge of current charging technology development. Until high-power charging technology matures, operations may resort to battery swapping rather than charging. As with commuter aircraft operations, fleet operators

38 Preparing Your Airport for Electric Aircraft and Hydrogen Technologies will need facilities and equipment for transportation, storage, and charging of swapped battery packs. However, unlike commuters, these flights will operate out of larger and more highly trafficked regional and hub airports. Operators will likely wish to minimize the inventory of expensive batteries at any given airport and maximize utilization. Thus, battery handling facilities will likely use chargers at high power (i.e., 600 kW) to enable multiple battery uses per day. In addition to the technology challenges presented by charging equipment, airport practitioners must be aware of the strategic planning challenges associated with building an effective elec- tric aircraft charging network. Airport operators must consider the type and density of electric aircraft traffic expected when determining the number, size, and placement of charging facilities. Beyond the charging infrastructure, the airport must consider the overall condition of its on- site power infrastructure because high traffic times may increase power demand by more than 1 MW. Transmission of such high-power levels may place a strain on existing electrical capacity, especially at smaller aviation facilities in remote areas. Upgrading electrical systems across an airport may be an expensive proposition, potentially prohibitively so to smaller airports. How- ever, many airports are exploring opportunities to enhance their power capacity with on-site power generation or through leveraging microgrid technologies. Microgrids are localized groups of interconnected loads and distributed energy sources that act as a single entity with respect to the grid. Local power generation, with or without an accompanying microgrid, is being implemented at many airports through solar, wind, or hydrocarbon-based technologies.