Transportation-mission-based Optimization of Heterogeneous Heavy-vehicle Fleet Including Electrified Propulsion

Commercial-vehicle manufacturers design vehicles to operate over a wide range of transportation tasks and driving cycles. However, certain possibilities of reducing emissions, manufacturing and operational costs from end vehicles are neglected if the target range of transportation tasks is narrow and known in advance, especially in case of electrified propulsion. Apart from real-time energy optimization, vehicle hardware can be meticulously tailored to best fit a known transportation task. As proposed in this study, a heterogeneous fleet of heavy-vehicles can be designed in a more cost- and energy-efficient manner, if the coupling between vehicle hardware, transportation mission, and infrastructure is considered during initial conceptual-design stages. To this end, a rather large optimization problem was defined and solved to minimize the total cost of fleet ownership in an integrated manner for a real-world case study. In the said case-study, design variables of optimization problem included mission, recharging infrastructure, loading--unloading scheme, number of vehicles of each type, number of trips, vehicle-loading capacity, selection between conventional, fully electric, and hybrid powertrains, size of internal-combustion engines and electric motors, number of axles being powered, and type and size of battery packs. This study demonstrated that by means of integrated fleet customization, battery-electric heavy-vehicles could strongly compete against their conventional combustion-powered counterparts. Primary focus has been put on optimizing vehicle propulsion, transport mission, infrastructure and fleet size rather than routing

Transportation Mission-Based Optimization of Heavy Combination Road Vehicles and Distributed Propulsion, Including Predictive Energy and Motion Control

This thesis proposes methodologies to improve heavy vehicle design by reducing the total cost of ownership and by increasing energy efficiency and safety.Environmental issues, consumers expectations and the growing demand for freight transport have created a competitive environment in providing better transportation solutions. In this thesis, it is proposed that freight vehicles can be designed in a more cost- and energy-efficient manner if they are customized for narrow ranges of operational domains and transportation use-cases. For this purpose, optimization-based methods were applied to minimize the total cost of ownership and to deliver customized vehicles with tailored propulsion components that best fit the given transportation missions and operational environment. Optimization-based design of the vehicle components was found to be effective due to the simultaneous consideration of the optimization of the transportation mission infrastructure, including charging stations, loading-unloading, routing and fleet composition and size, especially in case of electrified propulsion. Implementing integrated vehicle hardware-transportation optimization could reduce the total cost of ownership by up to 35% in the case of battery electric heavy vehicles. Furthermore, in this thesis, the impacts of two future technological advancements, i.e., heavy vehicle electrification and automation, on road freight transport were discussed. It was shown that automation helps the adoption of battery electric heavy vehicles in freight transport. Moreover, the optimizations and simulations produced a large quantity of data that can help users to select the best vehicle in terms of the size, propulsion system, and driving system for a given transportation assignment. The results of the optimizations revealed that battery electric and hybrid heavy combination vehicles exhibit the lowest total cost of ownership in certain transportation scenarios. In these vehicles, propulsion can be distributed over different axles of different units, thus the front units may be pushed by the rear units. Therefore, online optimal energy management strategies were proposed in this thesis to optimally control the vehicle motion and propulsion in terms of the minimum energy usage and lateral stability. These involved detailed multitrailer vehicle modeling and the design and solution of nonlinear optimal control problems

Transportation Mission Based Optimization of Heavy Vehicle Fleets including Propulsion Tailoring

Over decades freight vehicles were produced for a wide range of operational domains so that vehicle-manufacturers were not concerned much about the actual use-cases of the vehicles. Environmental issues, costumer expectations along with growing demand on freight transport created a competitive environment in providing better transportation solutions. In this thesis, it was proposed that freight vehicles can be designed more cost- and energy-efficiently targeting rather narrow ranges of operational domains and transportation use-cases. For this purpose, optimization-based methods were applied to deliver customized vehicles with tailored propulsion components that fit best given transportation missions and operational environment. Optimization-based design of vehicle components showed to be more effective considering optimization of transportation mission infrastructure simultaneously, including charging stations, routing and fleet composition and size, especially in case of electrified propulsion. It was observed that by implementing integrated vehicle hardware-transportation optimization, total cost of ownership can be reduced up to 35\%, in case of battery electric heavy vehicles.Furthermore, throughout thesis, the effect of propulsion system components size on optimal energy management strategy in hybrid heavy vehicles was studied; a methodology for solving fleet-size and mix-vehicle routing problem including enormous number of vehicle types were introduced; and the impact of Automated Driving Systems on electrified propulsion was presented

Impact of automated driving systems on road freight transport and electrified propulsion of heavy vehicles

The technological barriers to automated driving systems (ADS) are being quickly overcome to deploy on–road vehicles that do not require a human driver on–board. ADS have opened up possibilities to improve mobility, productivity, logistics planning, and energy consumption. However, further enhancements in productivity and energy consumption are required to reach CO2–reduction goals, owing to increased demands on transportation. In particular, in the freight sector, incorporation of automation with electrification can meet necessities of sustainable transport. However, the profitability of battery electric heavy vehicles (BEHVs) remains a concern. This study found that ADS led to profitability of BEHVs, which remained profitable for increased travel ranges by a factor of four compared to that of BEHVs driven by humans. Up to 20% reduction in the total cost of ownership of BEHVs equipped with ADS could be achieved by optimizing the electric propulsion system along with the infrastructure for a given transportation task. In that case, the optimized propulsion system might not be similar to that of a BEHV with a human driver. To obtain the results, the total cost of ownership was minimized numerically for 3072 different transportation scenarios that showed the effects of travel distance, road hilliness, average reference speed, and vehicle size on the incorporated electrification and automation, and compared to that of conventional combustion–powered heavy vehicles

Electrification of Urban Freight Transport - a Case Study of the Food Retailing Industry

Decarbonisation is a major challenge for the coming decades, for all industries, including the transport sector. Battery electric vehicles are a potential solution for the transport sector to reduce its carbon impact. Asides from the question whether there is sufficient supply of electric vehicles for freight transport, it is also unclear whether battery-powered trucks meet the practical requirements, especially in terms of their driving range. To investigate this, synthetic tours were generated by solving a Vehicle Routing Problem (VRP). This also generates the fleet size and composition depending on a set of different vehicle types. The network with underlying traffic conditions comes from an publicly available transport model. The generated tours are then simulated with an open-source transport simulation (MATSim), for both diesel and battery electric vehicles (BEVs). In a sensitivity study, two different purchase prices were considered for calculating vehicle costs. The case study uses a model of the food retailing industry for the city of Berlin. 56% of the tours can be driven without recharging. When recharged one time, 90% of the tours are suitable for BEVs. The costs for transporting the goods will increase by 17 to 23% depending on the assumption for the purchase prices for the BEVs. Using a well-to-wheel calculation, the electrification of all tours leads to a reduction of greenhouse gas (GHG) emissions by 26 to 96% depending on the assumed electricity production.DFG, 398051144, Analyse von Strategien zur vollständigen Dekarbonisierung des urbanen Verkehr

Drone-aided routing:A literature review

The interest in using drones in various applications has grown significantly in recent years. The reasons are related to the continuous advances in technology, especially the advent of fast microprocessors, which support intelligent autonomous control of several systems. Photography, construction, and monitoring and surveillance are only some of the areas in which the use of drones is becoming common. Among these, last-mile delivery is one of the most promising areas. In this work we focus on routing problems with drones, mostly in the context of parcel delivery. We survey and classify the existing works and we provide perspectives for future research.</p

Hydrogen-powered aviation – techno-economics of flying with green liquid hydrogen

The aviation sector set itself the target of net-zero CO2 emissions by 2050. However, there is no silver bullet such as a single technology to achieve this ambitious goal. New technologies like hydrogen (H2) propulsion do not only change future aircraft design but also fuel supply chains and operations of aircraft. In comparison to that, new fuels like drop-in synthetic kerosene imply mostly changes to the fuel production and supply infrastructure only, but might cause higher costs and lower resource efficiencies. The time for technology decisions is now. The sector’s main “workhorse” with the most take-offs and causing around 50% of all commercial aircraft emissions is the single-aisle aircraft segment. In this category, the next product launches are expected in the 2030s with final investment decisions by aircraft manufacturers already in less than 5 years. These new aircraft will shape the development of the sector’s climate impact in the following 20-30 years and will determine if the 2050 net-zero target can be reached. Consequently, a holistic techno-economic investigation is undertaken for this aircraft segment to evaluate the economic competitiveness of H2 propulsion concepts compared to other decarbonization options. It is derived that H2-powered single-aisle aircraft technology alone would lead to an average 5%-increase in total direct operating costs for airlines. Therefore, major technology developments are required targeting inter alia the onboard liquid H2 (LH2) tank, high-performing H2 combustion engines, and safe H2 fuel system integration. Moreover, the analysis shows that the main economic uncertainty arises from the supply costs for green LH2. Demand scenarios for 2050 indicate that larger-scale supply chains for aviation use might be needed. With annual demands of 100 ktLH2 or more, major national and intercontinental hub airports could take a H2 hub role dominating regional H2 consumption. Regarding the supply pathways for green LH2 to airports, three main options are identified: on-site, LH2 off-site, or gaseous H2 off-site production. In a first optimization task, it is derived that costs could reach 2.04 USD/kgLH2 in a 2050 base case scenario for locations with strong renewable energy source (RES) conditions and greater LH2 demands. This could lead to cost-competitive flying with H2 compared to fossil kerosene in combination with emission taxes. While the main costs are caused by the RES, water electrolysis, and H2 liquefaction, the costs for the LH2 refueling system only mark 3–5% of the total supply costs. If techno-economic uncertainties are reflected, the LH2 cost span ranges between 1.37–3.48 USD/kgLH2 at different airports with good and weaker RES conditions. For the latter, H2 imports from larger H2 markets/exporting countries are of special importance to achieve these costs – not only due to less performing RES locally, but also due to limited space availability. A European-centered case study is performed to combine the optimization of green LH2 supply and aircraft designs with the investigation of operational strategies in one specific air traffic network. In a 2050 scenario, it is calculated that LH2 could cost around 2–3 USD/kgLH2 at main European airports. Then, average total operating costs would be 3% less expensive than flying with synthetic kerosene in the considered network. Tankering, an operational strategy to save fuel costs, might only enable reduced operating costs for H2-powered aircraft in the early adoption phase when no larger-scale H2 import would be available. Finally, it is found that using LH2 for aircraft propulsion might lead to lower installation requirements for RES capacity when compared to the synthetic kerosene option. This resource efficiency aspect is another important criterion for choosing the future decarbonization technology in air travel since green electricity will most likely be a constraint resource in the next decades.Der Luftfahrtsektor strebt die CO2-Neutralität bis 2050 an. Jedoch gibt es zum Erreichen des Ziels bisher keine einzelne, klar überlegende Technologie. Konzepte zur Dekarbonisierung wie neue Flugzeuge mit Wasserstoff-(H2)-Antrieben erfordern nicht nur einen neuen Flugzeugentwurf, sondern auch neue Energiebereitstellungsinfrastruktur sowie neue Betriebskonzepte im Luftfahrtsystem. Im Gegensatz dazu könnten existierende Flugzeuge beim Einsatz nachhaltiger Kraftstoffe (SAF) weiter genutzt werden, wobei aber deren Wirtschaftlichkeit aufgrund hoher Kraftstoffkosten im Vergleich zu H2-betriebenen Flugzeugen geringer sein könnte. Die Zeit zum Treffen der notwendigen Technologieentscheidungen ist jetzt. Denn eine neue Produktgeneration im „Single-Aisle“-Flugzeugsegment, das die meisten Starts und etwa 50% der Emissionen in der kommerziellen Luftfahrt ausmacht, wird schon in den 2030er Jahren erwartet. Dafür müssen die endgültigen Investitionsentscheidungen der Flugzeughersteller bereits in weniger als 5 Jahren getroffen werden. Diese neuen Flugzeuge werden die Entwicklung der Klimawirkungen des Sektors in den nächsten 20-30 Jahren prägen und darüber entscheiden, ob das Ziel der CO2-Neutralität bis 2050 erreicht werden kann. Folglich wird in dieser Dissertation eine umfassende techno-ökonomische Untersuchung für Wasserstoffantriebe in diesem Flugzeugsegment durchgeführt. Es wird gezeigt, dass die Betriebskosten für Fluggesellschaften allein durch neue H2-betriebene Single-Aisle-Flugzeuge um durchschnittlich 5% steigen würden. Dafür sind wesentliche technologische Entwicklungen erforderlich – unter anderem leichte und kompakte Flüssigwasserstoff-(LH2)-Tanks, effiziente H2-Verbrennungsturbinen und eine sichere Integration des H2-Treibstoffsystems. Darüber hinaus zeigt die Betriebskostenanalyse, dass die Versorgungskosten für grünen LH2 die Hauptunsicherheit zur Wirtschaftlichkeit dieser Flugzeuge ausmacht. Dabei deuten 2050-Nachfrageszenarien schon darauf hin, dass möglicherweise große H2-Liefermengen für den Luftverkehr erforderlich sein könnten. Mit jährlichen Bedarfen von 100 ktLH2 oder mehr könnten große nationale und interkontinentale Drehkreuzflughäfen eine besondere Rolle als H2-Hubs übernehmen und den regionalen H2-Verbrauch dominieren. Für die Luftfahrt sind drei Bereitstellungsketten von grünem LH2 von Relevanz: Vor-Ort-Produktion von LH2 sowie Import von LH2 oder gasförmigem H2 von Produktionsorten außerhalb des Flughafens. Im Basisfallszenario 2050 ergeben sich in einer ersten Optimierung Kosten in Höhe von 2,04 USD/kgLH2 an Standorten mit guten Bedingungen für erneuerbare Energieerzeugung. Dies würde zur Wettbewerbsfähigkeit von Flügen mit H2 im Vergleich zu fossilem Kerosin in Verbindung mit Emissionsabgaben führen. Die Hauptkosten für LH2 werden durch die erneuerbare Energieversorgung, Wasserelektrolyse und H2-Verflüssigung verursacht. Das LH2-Betankungssystem macht nur 3-5% der Gesamtkosten aus. Wenn zusätzlich technisch-wirtschaftliche Unsicherheiten reflektiert werden, ergibt sich eine Kostenspanne von 1,37–3,48 USD/kgLH2 an verschiedenen Flughäfen mit günstigeren und teureren erneuerbaren Energiequellen. Bei letzteren Standorten können niedrigere Kosten nur durch H2-Importe aus größeren H2-Märkten erreicht werden. Eine auf Europa ausgerichtete Fallstudie kombiniert die Optimierung der grünen Wasserstoffversorgung und des Flugzeugdesigns mit der Untersuchung operativer Strategien in einem bestimmten Luftverkehrsnetzwerk. Im Basisfallszenario für 2050 wird berechnet, dass LH2 an Flughäfen in Europa etwa 2–3 USD/kgLH2 kosten könnte. Damit wären die durchschnittlichen Gesamtbetriebskosten im betrachteten Netzwerk um 3% günstiger als beim Fliegen mit synthetischem Kerosin. Das "Tankering", eine betriebliche Strategie zur Senkung der Treibstoffkosten, könnte nur in der frühen Einführungsphase von H2-betriebenen Flugzeugen eine Reduzierung der Betriebskosten ermöglichen, wenn H2-Importe noch nicht im größeren Maßstab verfügbar wären. Außerdem ergibt sich, dass der Einsatz von LH2 für den Flugzeugantrieb zu geringeren Ausbauanforderungen für erneuerbare Energiekapazitäten führen könnte im Vergleich zur Nutzung von synthetischem Kerosin. Dieser Aspekt der Ressourceneffizienz ist ein weiteres wichtiges Kriterium für die Wahl der zukünftigen Dekarbonisierungstechnologie im Luftverkehr, da grüner Strom in den nächsten Jahrzehnten höchstwahrscheinlich eine stark limitierte Ressource sein wird.Deutsche Forschungsgemeinschaft (DFG)/„Sustainable and Energy Efficient Aviation“/390881007/E

Market diffusion of alternative fuels and powertrains in heavy-duty vehicles: A literature review

With about 22%, the transport sector is one of the largest global emitters of the greenhouse gas CO₂. Long-distance road freight transport accounts for a large and rising share within this sector. For this reason, in February 2019, the European Union agreed to introduce CO₂ emission standards following Canada, China, Japan and the United States. One way to reduce CO₂ emissions from long-distance road freight transport is to use alternative powertrains in trucks — especially heavy-duty vehicles (HDV) because of their high mileage, weight and fuel consumption. Multiple alternative fuels and powertrains (AFPs) have been proposed as potential options to lower CO₂ emissions. However, the current research does not paint a clear picture of the path towards decarbonizing transport that uses AFPs in HDVs. The aim of this literature review is to understand the current state of research on the market diffusion of HDVs with alternative powertrains. We present a summary of market diffusion studies of AFPs in HDVs, including their methods, main findings and policy recommendations. We compare and synthesize the results of these studies to identify strengths and weaknesses in the field, and to propose further options to improve AFP HDV market diffusion modelling. All the studies expect AFPs on a small scale in their reference scenarios under current regulations. In climate protection scenarios, however, AFPs dominate the market, indicating their positive effect on CO₂ reduction. There is a high degree of uncertainty regarding the emergence of a superior AFP technology for HDVs. The authors of this review recommend more research into policy measures, and that infrastructure development and energy supply should be included in order to obtain a holistic understanding of modelling AFP market diffusion for HDVs