1 Influence of hill-length on energy consumption for hybridized heavy transports in long-haul transports MSc Pär Pettersson 1 ( par.petersson@chalmers.se ); Prof PhD MSc Bengt Jacobson 1 ( bengt.jacobson@chalmers.se ); PhD MSc Pär Johannesson 2 ( Par.Johannesson@sp.se ); PhD MSc Sixten Berglund 3 ( sixten.berglund@volvo.com ); PhD MSc Leo Laine 3 (leo.laine@volvo.com); 1) Chalmers University of Technology, Sweden, 2) SP Technical Research Institute of Sweden, Sweden, 3) Volvo Group Trucks Technology, Sweden. Abstract Goods transports are big producers of CO2, i.e. consumers of energy. The conventional transport vehicles such as tractor-semitrailers can be replaced by long combination vehicles (LCVs). By doing so, fuel consumption will be reduced drastically, with up to 30%, mainly thanks to the reduced aerodynamic resistance per pay load mass and/or volume. Further reduction of CO2 improvements can be made by hybridization, if the road topography demands variable propulsion power due to up- and downhills. This gain is emphasized for heavier vehicles. So, hybridized LCVs are of special interest. When developing vehicles, or selecting vehicle for a certain transport, one needs to assume an operating cycle. To describe the operating cycle correctly is very important for this purpose. Traditionally, the magnitude of road grades is the only topography measure used to characterise the road. In this paper it is studied how an additional measure, hill length, influences these heavy hybridized LCVs. Together one can see these two measures as amplitude and wavelength. It is shown how energy saving varies for different types of roads (combinations of grade magnitude and hill- length) and different energy buffer sizes. Road topography is statistically generated for a good coverage of road types, but also examples of real roads are marked within these synthetic roads. The result can be combined with estimates of hybridization costs and conclusions can be drawn when it is beneficial to hybridize and with how large buffer. The main takeaways from the paper are that the potential energy savings for heavy LVCs due to hybridization are significant and that the hill-length is an important characteristic measure to include in operating cycle definitions. Keywords Goods transport, Long Combination Vehicle, High Capacity Transport, Hybrid propulsion, Energy saving, Energy consumption, Road description, Road topography 1. Introduction 1.1 Background Goods transports are big producers of CO2 therefore potential ways to reduce the energy consumption are important to consider. One way of achieving a considerable reduction is to allow trucks with longer trailer combinations than the conventional tractor-semitrailer; for example the semitrailer-dolly-semitrailer (A- double) depicted in Figure 1. The reduction in energy consumption per pay load is mainly due to the reduction in aerodynamic resistance.