2 WHY ELECTROMOBILITY AND WHAT IS IT? Anders Grauers Department of Signals and Systems, Chalmers University of Technology* Steven Sarasini Department of Energy and Environment, Chalmers University of Technology** Magnus Karlström Chalmers Industriteknik * Automatic control research group ** Division of Environmental Systems Analysis Chapter reviewer: Björn Sandén, Environmental Systems Analysis, Energy and Environment, Chalmers In this chapter we examine the notion of electromobility and aim to provide a working definition of the term that underpins the analyses presented in the rest of this e-book. We also describe electromobility in technological terms by presenting various technological configurations of electric vehicles, charging infrastructure and energy supply. We then proceed to examine why electromobility is currently supported as a favourable means to transform road transport by discussing drivers and barriers of change in the automotive industry. Whilst electromobility repre- sents a significant technical challenge, it also requires complex social changes. By arguing from different perspectives we hope to illustrate that electromobility is best understood by considering a range of systemic perspectives found in this and later chapters of this e-book. WHAT IS ELECTROMOBILITY? In this e-book we define electromobility as a road transport system based on vehicles that are propelled by electricity. Some road vehicles are equipped with technologies that make them capable of producing their own electricity (e.g. hybrid electric vehicles). Others utilise energy supplied by a source of electricity outside the vehicle – usually the electric grid. This definition works well for battery electric vehicles as well as for vehicles that do not store electrical energy such as trolley busses. A key feature of our definition is that it focuses on systemic aspects of electromo- Systems Perspectives on Electromobility 2013, ISBN 978-91-980973-1-3 2013, Electromobility on Perspectives Systems bility. A transport system using electricity from the grid, for instance, can utilise 10 energy from many different sources without major modifications to electric vehicles or energy supply systems. This allows for local variations in energy supply and gradual changes to energy supply systems. Electromobility may thus improve the flexibility and robustness of the transport sector in that electrified vehicles can utilise different types of energy sources. Electricity can be produced from nuclear power, fossil fuels and abundant renewable resources such as solar and wind. This could make electromobility more favourable than other technological alterna- tives such as vehicles that utilise biofuels, because the production of biofuels is limited by the availability of biomass (see Chapter 5 for a comparison of system 1 efficiencies). Electromobility can also help to reduce CO2 emissions, especially if electricity is produced using renewable sources (Chapter 6). However, if vehicles utilise electricity produced from coal, the climate impacts of electric propulsion could be negative when compared to gasoline or diesel fuelled vehicles. This exemplifies that systems thinking is key to understanding the benefits and draw- backs of different electric vehicle technologies and systems. Furthermore, electromobility is a complex phenomenon that will involve technologi- cal development, policymaking, innovation, new business models, new driving behaviour and new linkages between industries. The systemic aspects of electro- mobility thus reach far beyond mere technical aspects and a transition to electric propulsion must be understood as a process of socio-technical transformation. TECHNOLOGIES FOR ELECTROMOBILITY Electromobility requires several new technologies. This section provides an over- view of the currently most interesting technological alternatives and configurations. It is, however, not an exhaustive list of all possible technologies (see also Chapter 3). Figure 2.1 shows examples of energy sources and technologies that can transfer energy to electric vehicles. Note that energy sources can be selected irrespective of the technology used for transferring energy to vehicles. The primary means of transferring energy to vehicles is to charge the vehicle while it is parked using a cord or via wireless charging. In order to extend vehicles’ driving range it is also possible to use rapid chargers that significantly recharge batteries in about 10 to 30 minutes. Alternatively, battery switching involves exchanging discharged bat- teries for fully charged ones, usually at a switching station. To reduce (or eliminate) the need for battery capacity it is also possible to supply electric vehicles with energy whilst in motion, either during the whole drive or parts of it. A final way to supply vehicles with electrical energy is to produce hydrogen via electrolysis and store energy in hydrogen tanks rather than batteries. Three electromobility drivetrain configurations are presented in this chapter: battery electric vehicles (BEVs), continuous power supply electric vehicles (both a conductive and an inductive version) combined with electric road systems (ERS, see also Chapter 14), and fuel cell vehicles (FCVs) (Figure 2.1). Due to limitations in each of these, some hybrid drivetrains are also of interest since the combination of two drivetrains can benefit from their respective strengths and compensate for weaknesses. 1 See Systems Perspectives on Biorefineries 2013 for discussions on various aspects of biofuel use. 11 Other electricity sources Coal/Biomass Nuclear Wind Solar Energy source (any electric power) source Energy H2 H2 Fuel cell Quick-charging Battery swapping Filling Hydrogen While stopped + Takes 2 minutes Generated from electricity + Takes 10 to 30 minutes + Unlimited driving range + Takes 5 minutes + Extends driving range – Requires extra batteries + Unlimited driving range Charge while parked Supply while driving – High power, expensive – Expensive swapping – Expensive filling station or With cable or wireless Conductive or wireless station hydrogen distribution + Low power, cheap + Unlimited driving range Energy to vehicle technology Energy + No or small battery – Takes 3 to 12 hours – Limited driving range – Expensive infrastructure Main limitation: Main limitation: Batteries are expensive Continuous supply systems are and have limited energy, expensive, sensitive to power leading to limited driving interruptions and do not work in crossings. range. Solution: Solution: Solution: Adding an ICE allows Adding on-board Adding an ICE allows a unlimited driving range and batteries allows a supply supply system that is not allows using a smaller battery. system that is not available everywhere. available everywhere. Handles long time Handles only limited time without supply. without supply. Some hybrid drive train versions Figure 2.1 Examples of electricity sources, drivetrain configurations and technologies to transfer electrical energy to vehicles. BEVs run solely on electrical energy from a battery and have a fully electric drivetrain. Batteries can be charged in many different ways as shown in Figure 2.1. A major limitation of BEVs is that the driving range is dependent on battery size, which in turn is constrained by cost and weight. 12 Plug-in hybrids (PHEV) and range extender vehicles are electric vehicles that combine battery-powered electric machines and combustion engines. This combi- nation can reduce range limitations; allow the use of smaller and cheaper on-board batteries; and reduce the need for a charging infrastructure. The most likely backup power source in such vehicles in the short term is an internal combustion engine. In the long term other types of backup power sources may be used such as fuel cells. Plug-in hybrids come in various configurations with different types of transmission and with different ratios between the size of the combustion engine and the electric machine (see Chapter 3). From an energy-system perspective they all have the same basic functionality of allowing vehicles to run on electricity from the grid, but whenever there is a limit due to battery capacity they can run on alternative fuels until the battery is recharged. Vehicles with a continuous power supply draw energy from the electricity grid whilst in motion and thus reduce the need to store energy on-board. However the construction of a road infrastructure that integrates conductive power lines or inductive rails requires large investments, and the system would be vulnerable to fluctuations in electricity supply. Hence hybrid configurations that include on-board energy storage devices (batteries or some other secondary power source) may be more attractive. The secondary energy source can be used in road junctions where it is difficult to construct a continuous supply infrastructure; on roads where a continuous supply infrastructure are not economically warranted or not yet installed; and in the event of fluctuations in electricity supply. Fuel cell vehicles (FCV) are vehicles that carry energy in the form of a fuel such as hydrogen that can be transformed into electricity on-board using fuel cells. FCVs allow for longer driving distances, but require a hydrogen-refuelling infrastructure. Refuelling takes only a few minutes and is much faster than charging batteries, even where fast charging is available. During operation a fuel cell cannot quickly change the power output and FCVs typically also use a small battery to match rapid changes in power demand