Pollutant emissions analysis of three plug-in hybrid electric vehicles using different modes of operation and driving conditions

To evaluate real-world energy consumption and tail-pipe emissions of current plug-in hybrid electric vehicles (PHEVs), we tested three PHEVs in different driving conditions. We considered measurements of emissions at different ambient temperatures and for various operating conditions regarding hybridization. The results show that the initial battery state-of-charge (SoC) determines the absolute CO2 emissions as CO2 emissions decrease with a higher proportion of electric driving. Therefore, the use of different hybrid driving strategies can have a strong influence on the overall fuel-saving potential. This does not apply to other pollutants such as NOx and particles, as the emission of these pollutants depends on the operating conditions of the internal combustion engine. RDE tests with a high proportion of electric driving show, in some cases, higher pollutant emissions than in tests with a low electric share. In general, the emission measurements done under real driving conditions show a higher variance compared to the test bench tests. In the case of PHEVs, this effect is further increased due to the different choice of driving modes and engine cold starts during electric driving. The variance of these parameters makes it difficult to estimate the emission benefits of PHEVs

Biofuels and alternative fuels in Europe: Status, Challenges and Technology-Trends

From a historical point of view, using agricultural products for fueling of transport is a well-known objective among automobile engineers, but never became accepted in Europe. But as the motivations of political and economic actors for searching alternatives to fossil fuels have changed, the idea of using renewable energies for transport systems is more popular than ever and the use of such fuels is widely supported. Biofuels and alternative fuels provide a way to lower greenhouse gas emissions and reduce dependencies on fossil fuel resources. However, biomass resources in Europe as well as reductions of greenhouse gas emissions compared to fossil fuels are limited. Four factors are important: crop characteristics, climate conditions (geography), conversion and powertrain technologies. This paper gives an overview of different types of alternative fuels relevant in Europe and the status of production and demand for biofuels in the transport sector in Europe. We aim to explain how the developments in this sector correspond with the political targets of the European Union and which measures are taken. In order to reach these targets, the member states have implemented different support systems. Yet it seems to be unlikely that the goals given by EU policy can be reached without further technological developments. Regarding these difficulties in establishing a European biofuel trade system, we analyse the research efforts supported by the EU. Such programs mainly consider resources, production and performance of alternative fuels as well as their adaptation to vehicles. Drawing present and prospective powertrain technologies into account, we compare different alternative fuel chains and present scenarios for future fuels and emissions

An international dialogue about electric vehicle deployment to bring energy and greenhouse gas benefits through 2030 on a well-to-wheels basis

In this paper, we aim to assess the potential influence of increased adoption of electric vehicles (EVs) on a well-to-wheel (WTW) basis in the four countries with highest passenger car sales (Germany, the United States, China, and Japan), and Norway which represents a highly renewable energy market on greenhouse gas emissions. To characterize these emissions, we define critical parameters regarding fleet composition, activity, efficiency and fuel production in each country. Overall, with today’s technology at a national average level, on a per km driven basis, battery electric vehicles emit fewer greenhouse gases than conventional vehicles in all countries. Though vehicle energy consumption is similar in all countries, electricity production energy efficiency and greenhouse gas emissions per kWh electricity vary considerably, with Norway and China representing the low and high emitting endpoints, respectively. As electricity generation decarbonizes, EVs have the potential to be lower greenhouse-gas emitting than gasoline vehicles in all countries considered. The complexity of EV analysis across international boundaries, time periods, and environmental media complicates communication of EV benefits to stakeholders. Analysts must continue to address and clearly communicate the influence of EV and electricity production technology advancement into the future on EV impacts on all environmental media (air, water, land)

Land transport development in three integrated scenarios for Germany: Technology options, energy demand and emissions

Today, transportation contributes significantly to greenhouse gas emissions and air pollution. However, new technologies are emerging and existing technologies are being further improved. This article presents the results of a comprehensive study on the development of drive-trains, resulting electricity and fuel consumption as well as emissions of CO2 and selected air pollutants in land transport in Germany. This includes a quantitative assessment of technological potentials and of resulting energy consumption and emissions. The scenario building followed an explorative approach. Only the scenario depicting a consistent transition towards electrified mobility and regulated emissions from the energy system leads to a significant reduction in transport related CO2 emissions. Yet, the analysis shows that it is unlikely that the German emission reduction target in 2030 for the transport sector will be met. Nevertheless, the integrated scenario analysis demonstrates that only a joint de-carbonization of both transport and electricity systems lead to a significant reduction of emissions