The DIONE cost curve module produces curves which describe the costs of reducing vehicle energy consumption or CO2 emissions, versus a reference vehicle of the same segment. These reductions can stem from efficiency improvements on a given conventional powertrain, e.g., through improved aerodynamics or improvements in motor operation, as well as from the transition to a more efficient alternative powertrain, e.g., battery electric propulsion. Two energy reduction modes are available; therefore the cost function can be plotted against two axes: Conventional energy reduction cost curve: It corresponds to the reduction of liquid and/or gaseous fuel consumed to propel the vehicle, with respect to the reference vehicle. Regarding CO2 emissions we have to distinguish three cases: For pure internal combustion engines (ICE) and full or mild hybrids using CO2-emitting fuels (such as combustion engine powertrains using diesel, gasoline, or natural gas as fuels), CO2 emissions are proportional to fuel consumption. Thus, the conventional energy consumption reduction corresponds to the relative CO2 emission reduction. For plug-in hybrid electric vehicles (PHEV) or range-extended electric vehicles (REEV) using CO2-emitting fuels, the reduction includes fuel saving due to usage of the energy stored in the battery. Therefore, also in this case, “conventional” fuel reduction relative to the reference vehicle is proportional to relative tailpipe CO2 emission reduction. Fuel cell electric vehicles (FCEV) or hydrogen internal combustion engine vehicles (H2 ICE) do not emit any tailpipe CO2. Therefore, there is no CO2 emission reduction from applying efficiency technologies. Total energy reduction cost curve: It corresponds to the overall reduction of the total energy consumed by the vehicle. In this case, we can distinguish three cases: For pure ICE or FCEV or H2 ICE or REEV, this corresponds to conventional energy reduction. Thus, the “total energy” reduction cost curve overlaps with the “conventional” energy reduction cost curve. For PHEV or REEV, both the change in consumption of electric energy (which is not included in “conventional”) and the reduction of conventional fuels, relative to the reference vehicle, are taken into account. Therefore, total energy reduction is lower than conventional energy reduction. For battery electric vehicles (BEV), which consume only electricity, only the “total energy” reduction curve is defined. It shows the energy consumption reduction relative to the energy consumed by the reference vehicle. As an example, cost curves for lower medium segment cars registered in the year 2030 are shown below. Spark ignition Compression ignition Spark ignition plug-in hybrid electric vehicle Compression ignition plug-in hybrid electric vehicle Spark ignition range extended electric vehicle Compression ignition range extended electric vehicle Battery electric vehicle Fuel cell electric vehicle Figure 1. JRC 2023 cost curves for lower medium segment cars, 2030, all powertrains. Red curves: total energy consumption reduction cost curves, blue curves: liquid/gaseous fuel consumption (“conventional”) reduction cost curves. High (dashed), typical (solid) and low (dotted) curves are shown for each powertrain. Powertrains: SI – spark ignition, CI – compression ignition, ICE – internal combustion engine, HEV – mild hybrid electric vehicle, PHEV – plug-in hybrid electric vehicle, REEV – range extended electric vehicle, BEV – battery electric vehicle, FCEV – fuel cell electric vehicle. The y-axis displays the technology costs for reaching a given energy consumption reduction (in EUR/vehicle), measured under the Worldwide harmonized Light duty vehicles Test Procedure (WLTP), relative to the reference vehicle. Reference vehicles are 2013 new vehicles of the same segment, and reference powertrains are conventional gasoline spark ignition vehicles for all powertrains using spark ignition motors, as well as for battery and fuel cell electric vehicles (SI ICE+HEV, SI REEV, SI REEV, BEV, and FCEV), and conventional diesel compression ignition vehicles for all vehicles equipped with a compression ignition engine (CI ICE+HEV, CI REEV, and CI REEV). There are three cost scenarios; low, typical, and high cost, reflecting uncertainties in the projections of technology costs. The JRC has produced a complete set of 336 Light Duty Vehicle cost curves, covering four car and three van segments, eight powertrains, and the years from 2025 to 2050. The technology input data has been sourced from a study on behalf of the European Commission (Hill et al. (forthcoming)1 ). The full set of cost curve parameters has been published in an open dataset and can be found in the Resources page. More details on the cost curve model are documented in The JRC DIONE model version II. 1Ricardo Energy & Environment et al. , Technical support for analysis of some elements of the post-2020 CO2 emission standards for cars and vans, Final project summary report, Service Request No. 2020/03 under Framework contract CLIMA.A4/FRA/2019/0011 2Krause, J., Le Corguillé, J., Saporiti, F. and Arcidiacono, V. , The JRC DIONE model version II, Publications Office of the European Union, Luxembourg, 2024, JRC135666, ISBN 978-92-68-10950-2, ISSN 1831-9424
