Dennis Dreier

Bio: Dennis Dreier is an academic researcher from Royal Institute of Technology. The author has contributed to research in topics: Bus rapid transit & Sustainable transport. The author has an hindex of 5, co-authored 9 publications receiving 73 citations.

Well-to-Wheel analysis of fossil energy use and greenhouse gas emissions for conventional, hybrid-electric and plug-in hybrid-electric city buses in the BRT system in Curitiba, Brazil

Abstract: This study estimates Well-to-Wheel (WTW) fossil energy use and greenhouse gas (GHG) emissions for six types of city buses with conventional, hybrid-electric and plug-in hybrid-electric powertrains, including two-axle, articulated and bi-articulated chassis in the BRT (Bus Rapid Transit) system in Curitiba, Brazil. Particular emphasis is put on the operation phase (Tank-to-Wheel, TTW) of the city buses using the Advanced Vehicle Simulator (ADVISOR). The simulations are based on real-world driving patterns collected from Curitiba, comprising 42 driving cycles that represent city bus operation on seven BRT routes with six operation times for each. Hybrid-electric and plug-in hybrid-electric two-axle city buses use 30% and 75% less WTW fossil energy per distance compared to a conventional two-axle city bus (19.46 MJfossil,WTW/km). This gives an absolute reduction of 1115 gCO2e,WTW/km in WTW GHG emissions when operating a plug-in hybrid-electric city bus instead of a conventional two-axle city bus (1539 gCO2e,WTW/km). However, a conventional bi-articulated city bus can be environment-friendlier than hybrid-electric city buses in terms of WTW fossil energy use and WTW GHG emissions per passenger-distance, if its passenger capacity is sufficiently utilised. Nonetheless, the plug-in hybrid-electric city bus remains the most energy-efficient and less polluting option. Hybrid-electric and plug-in hybrid-electric powertrains offer the possibility to achieve much higher levels of decarbonisation in the BRT system in Curitiba than the blending mandate of 7%vol biodiesel into diesel implemented in Brazil in 2016. In addition, the simulations show that TTW energy use can considerably vary by up to 77% between different operation times, BRT routes and types of city buses. In conclusion, advanced powertrains and large passenger capacity utilisation can promote sustainability in Curitiba’s BRT system. The results of this analysis provide important insights for decision makers both in Curitiba and other cities with similar conditions.

The influence of passenger load, driving cycle, fuel price and different types of buses on the cost of transport service in the BRT system in Curitiba, Brazil

Abstract: This study analyses the influence of passenger load, driving cycle, fuel price and four different types of buses on the cost of transport service for one bus rapid transit (BRT) route in Curitiba, ...

OSeMOSYS-PuLP : A Stochastic Modeling Framework for Long-Term Energy Systems Modeling

Abstract: Recent open-data movements give access to large datasets derived from real-world observations. This data can be utilized to enhance energy systems modeling in terms of heterogeneity, confidence, and transparency. Furthermore, it allows to shift away from the common practice of considering average values towards probability distributions. In turn, heterogeneity and randomness of the real-world can be captured that are usually found in large samples of real-world data. This paper presents a methodological framework for an empirical deterministic–stochastic modeling approach to utilize large real-world datasets in long-term energy systems modeling. A new software system—OSeMOSYS-PuLP—was developed and is available now.It adds the feature of Monte Carlo simulations to the existing open-source energy modeling system (the OSeMOSYS modeling framework). An application example is given, in which the initial application example of OSeMOSYS is used and modified to include real-world operation data from a public bus transport system.

Transition Technologies for Electrification and Optimisation of Bus Transport Systems

Abstract: The topical issue of climate change has increasingly become important as scenarios indicate an increase of 2.5–7.8°C in the global mean temperature by the end of this century, if no greenhouse gas ...

Smart City Concepts in Curitiba - innovation for sustainable mobility and energy efficiency: Project NEWSLETTER, November 2016

Abstract: Smart City Concepts in Curitiba - innovation for sustainable mobility and energy efficiency : Project NEWSLETTER, January 2016

Hydrogen Fuel Cell Vehicles; Current Status and Future Prospect

Abstract: The hazardous effects of pollutants from conventional fuel vehicles have caused the scientific world to move towards environmentally friendly energy sources. Though we have various renewable energy sources, the perfect one to use as an energy source for vehicles is hydrogen. Like electricity, hydrogen is an energy carrier that has the ability to deliver incredible amounts of energy. Onboard hydrogen storage in vehicles is an important factor that should be considered when designing fuel cell vehicles. In this study, a recent development in hydrogen fuel cell engines is reviewed to scrutinize the feasibility of using hydrogen as a major fuel in transportation systems. A fuel cell is an electrochemical device that can produce electricity by allowing chemical gases and oxidants as reactants. With anodes and electrolytes, the fuel cell splits the cation and the anion in the reactant to produce electricity. Fuel cells use reactants, which are not harmful to the environment and produce water as a product of the chemical reaction. As hydrogen is one of the most efficient energy carriers, the fuel cell can produce direct current (DC) power to run the electric car. By integrating a hydrogen fuel cell with batteries and the control system with strategies, one can produce a sustainable hybrid car.

Fast-charging station deployment for battery electric bus systems considering electricity demand charges

Abstract: Battery electric buses (BEBs) are considered a promising alternative for bus fleets to alleviate the growing environmental problems in urban areas, and fast-charging technology has been introduced to BEB systems to help electric buses provide uninterrupted service without the need to carry a large onboard battery. The general consensus is that fast-charging may lead to high electricity demand charges, thus compromising the competitiveness of electric bus systems. However, a majority of current electric bus fast-charging station deployment models ignore these charges. The present study addresses this gap by explicitly considering the electricity demand charges in the optimal deployment problem of fast-charging stations for battery electric bus systems. The problem is formulated as a mixed integer linear programming model with the objective of minimizing the total cost of vehicle batteries, fast-charging stations, energy storage systems, and electricity demand charges. Numerical studies based on a real-world bus network in Salt Lake City, Utah, are conducted to demonstrate the effectiveness of the proposed model. The results show that the proposed model can effectively determine the deployment of fast-charging stations, the design of vehicle battery sizes, as well as the installation of energy storage systems. This study demonstrates that energy storage systems are a potential remedy for high demand charges from fast-charging.

Technology: a necessary but not sufficient condition for future personal mobility

Abstract: Technological advances revolutionize industrial processes, science, communications, and our way of life. However, developed societies have reached a stage in which the fascination with technological innovations often results in their indiscriminate consumption. In this paper, road traffic is used as a line of argument to demonstrate that the random introduction of technology does not imply benefits to society. Particularly, it is analyzed why some of the potential benefits of technological progress are lost in fields such as traffic monitoring, data handling, and traffic management, or in sustainable mobility initiatives, such as the introduction of electric vehicles or the implementation vehicle sharing projects. The risks faced in the future advent of autonomous vehicles are also discussed, and ideas for improvement suggested. A critical reflection on other transportation modes that are expected to be realized in the near future is included as well. The performed analysis evidences that the potential improvement in personal mobility will not become a reality if it exclusively relies on the latest technological devices, in line with consumers’ fantasies or economic interests. This is a statement that could be generalized to many other fields. The implementation/consumption of a particular technology should not be an objective in itself, but a tool to bring benefits to society.