Impact of WLTP introduction on CO2 emissions from M1 and N1 vehicles: Evidence from type-approval and 2018 EEA data

The analysis of official type-approval documents covering the period September 2017 - August 2018 and which were uploaded in the ETAES platform has given a first insight of the impact of the introduction of the WLTP procedure on declared and measured CO2 emissions. The first topic analysed was the ratio between declared WLTP and NEDC emissions. On average, this ratio is higher for diesel ICE vehicles compared to gasoline ICE vehicles. The mean ratio for diesel VH was 1.26 for M1 category and 1.28 for N1 and for VL 1.18 for M1 and 1.22 for N1 category. The 2018 EEA data showed an average ratio of 1.25 for M1 and 1.27 for N1 category. For gasoline ICE vehicles the mean ratio for VH is 1.16 for M1 1.19 for N1 category and for VL 1.13 for M1 and 1.14 for N1 category. The 2018 EEA data show an average ratio of 1.19 for M1 1.16 for N1 category. The highest average ratio for diesel and gasoline VH was calculated for OEM_3 group and for VL for OEM_15 (diesel) and OEM_3 (gasoline) groups. The 2018 EEA registrations data show the highest average ratio coming from OEM_3 (diesel) and OEM_11 (gasoline) groups. For NOVC-HEVs and OVC-HEVs the data sets analysis were much smaller and any conclusions drawn should be treated with caution. The mean WLTP/NEDC ratio for NOVC-HEVs was 1.22 (VH) and 1.18 (VL), which is higher than that of gasoline ICE vehicles. For all OVC-HEVs analysed (weighted-combined CO2 emissions) the ratio for VH is 1.13, but with a range from 0.34 to 1.44 and for VL the average was 1.03 (range: 0.31-1.32). In the 2018 EEA data NOVC-HEVs and OVC-HEVs could not be distinguished. Analysis of Emission type-approval documents (ETA) revealed that for the majority of IP families analysed (70% for VH and 73% for VL) the declared WLTP values were less than 5% higher than the WLTP measured values. In 26% of cases for VH and 23% for VL the over-declaration was between 5% and 10%. In only 4% of cases for VH and 4% for VL OEM’s over-declaration was above 10% (but always below 20%). In total, 18% (266) of IP families are type-approved with only vehicle high (VH), which leads to higher CO2 emissions compared to the interpolation approach. Some OEMs are only type-approving VH (OEM_13, OEM_16, OEM_17, OEM_18, OEM_19, OEM_21, OEM_22, OEM_23, OEM_24, OEM_25, OEM_27, OEM_28), but except OEM_13, the other OEM groups have very low registrations. OEM groups with high registrations (more than half million) and high % of IP families with only VH are: OEM_7 (24%), OEM_5 (22%), OEM_2 (20%), OEM_9 (7%), and OEM_3 (6%). OEM_12 and OEM_10 are another OEMs with high % of IP families with only VH (91% and 73%, respectively) and registrations higher than 200,000. Various inconsistencies and issues have been identified in the data collected. Such inconsistencies should be addressed to ensure correct implementation of the legislation and a level playing field.JRC.C.4-Sustainable Transpor

Analysing the potential of a simulation-based method for the assessment of CO2 savings from eco-innovative technologies in light-duty vehicles

[EN] Mandatory targets are set in Europe for Carbon Dioxide (CO2) emissions of light-duty vehicles. EU law recognises the potential of certain innovative technologies to contribute to reducing CO2 emissions. Vehicle systems and innovations are becoming increasingly complex, and the accurate quantification of their benefits increasingly difficult. The study investigates the potential of the CO2MPAS simulator to serve this purpose. Two innovative technologies were studied, Light-emitting diode (LED) lighting systems, efficient alternators (EA), and their combination. The model was validated on detailed test results from eight vehicles. A total of 452 passenger cars, for which test data were available, were subsequently simulated using CO2MPAS simulator. The mean simulated CO2 savings was 0.91gCO2/km (LED lights), 0.98 gCO2/km (EA), and 1.78 gCO2/km (combined). Results show that simulated CO2 savings were comparable to those calculated using the existing standardised method. For gasoline and diesel vehicles respectively, the difference in CO2 savings between simulated and existing method was 2.8% and 0.14% in the LED lights case, and 0.6% and 0.67% in the alternator case. In the combined case, the difference was calculated to be 1.7% and 0.34%. Similar approaches could be used in the future for accurately capturing the benefits of more complex technologies.Authors would like to thank Mr Filip Francois, Ms Susanna Lindvall, and Mr Sotirios Kakarantzas of DG Climate Action for their valuable comments. A special thanks goes to Dr Vincenzo Arcidiacono who guided in the targeted sample CO2MPAS simulations which gave the starting point for this work, and to Dr Giuseppe Di Pierro who provided insight and expertise that greatly improved this work.Gil-Sayas, S.; Komnos, D.; Lodi, C.; Currò, D.; Serra, S.; Broatch, A.; Fontaras, G. (2022). Analysing the potential of a simulation-based method for the assessment of CO2 savings from eco-innovative technologies in light-duty vehicles. Energy. 245:1-14. https://doi.org/10.1016/j.energy.2022.12323811424

Μελέτη περιβαλλοντικών επιπτώσεων & επικινδυνότητας μονάδων παραγωγής συσσωρευτών

Περίληψη: Η αυξανόμενη χρήση μπαταριών (συσσωρευτών) τα τελευταία χρόνια οφείλεται στην ραγδαία ανάπτυξη των ανανεώσιμων πηγών ενέργειας και στην υιοθέτηση νέων πολιτικών, αναφορικά με τα καύσιμα, φιλικότερων προς το περιβάλλον. Η παραγωγή τους, όμως, πρέπει να γίνεται κάτω από συγκεκριμένα μέτρα ώστε οι μπαταρίες να μην αποτελούν κίνδυνο για την ζωή, την υγεία και το περιβάλλον αλλά να είναι απόλυτα εναρμονισμένες με την οικολογική συνείδηση. Αντικείμενο μελέτης, λοιπόν, της παρούσας εργασίας είναι ο εντοπισμός των κινδύνων αυτών και ο περιορισμός τους με την εφαρμογής κατάλληλων μέτρων. Προηγείται η καταγραφή και ανάλυση των πηγών κινδύνου για το περιβάλλον και την ανθρώπινη υγεία ώστε να προσδιοριστεί με ακρίβεια το πρόβλημα. Εντοπίζονται οι αέριοι, υγροί και στερεοί ρύποι που προκύπτουν από μία μονάδα παραγωγής συσσωρευτών και παρουσιάζονται οι επιπτώσεις τους. Στη συνέχεια, γίνεται σύγκριση των εκπεμπόμενων ρύπων με τα αποδεκτά όρια όπως ορίζονται από την Ελληνική Δημοκρατία και την Ευρωπαϊκή Ένωση ώστε να προσδιοριστεί το μέγεθος του κινδύνου που πρέπει να περιοριστεί. Στην παραπάνω καταγραφή προσδιορίζονται επίσης και οι εργονομικοί κίνδυνοι ώστε να ακολουθήσει μία μελέτη επικινδυνότητας για τον χώρο εργασίας της μονάδας παραγωγής συσσωρευτών. Το δεύτερο σκέλος της εργασία αφορά τους τρόπους αντιμετώπισης του προβλήματος που αναλύθηκε προηγουμένως. Ως λύσεις παρουσιάζονται μονάδες εξουδετέρωσης και απομόνωσης των ρύπων, όπως η μονάδα επεξεργασίας λυμάτων και η πλυντηρίδα αερίων. Προτείνονται μέτρα προστασίας των εργαζομένων και μέτρα περιορισμού του ρυπαντικού φορτίου προς το περιβάλλον. Με στόχο της πρακτική και εφαρμοσμένη προσέγγιση του θέματος η εργασία θα στηριχθεί σε πραγματικά δεδομένα μονάδας παραγωγής συσσωρευτών

Benchmarking the driver acceleration impact on vehicle energy consumption and CO2 emissions

The study proposes a methodology for quantifying the impact of real-world heterogeneous driving behavior on vehicle energy consumption, linking instantaneous acceleration heterogeneity and CO2 emissions. Data recorded from 20 different drivers under real driving are benchmarked against the Worldwide Harmonized Light Vehicle Test Cycle (WLTC), first by correlating the speed cycle with individual driver behavior and then by quantifying the CO2 emissions and consumption. The vehicle-Independent Driving Style metric (IDS) is used to quantify acceleration dynamicity, introducing driving style stochasticity by means of probability distribution functions. Results show that the WLTC cycle assumes a relatively smooth acceleration style compared to the observed ones. The method successfully associates acceleration dynamicity to CO2 emissions. We observe a 5% difference in the CO2 emissions between the most favourable and the least favourable case. The intra-driver variance reached 3%, while the inter-driver variance is below 2%. The approach can be used for quantifying the driving style induced emissions divergence.ISSN:1361-9209ISSN:1879-234

The development and validation of a vehicle simulator for the introduction of Worldwide Harmonized test protocol in the European light duty vehicle CO2 certification process

As of July 2017, the emissions type-approval of light-duty vehicles in Europe is based on the Worldwide Harmonized Light-duty vehicles Test Procedure (WLTP), introduced to replace the old and outdated New European Driving Cycle (NEDC) test procedure. Since some elements of the European Legislation are still based on the NEDC (2020 CO2 emission targets, vehicle labelling, national vehicle taxation policies, etc.) in order to allow sufficient lead time to vehicle manufacturers and national authorities to adapt to the new procedure, a simulation-based approach was chosen to calculate CO2 emissions and fuel consumption according to the NEDC regime in the period 2017–2020. To achieve this objective without significantly increasing the cost and duration of the certification procedure, existing regulation foresees that vehicles are tested over the WLTP for CO2 emissions, the test results are used as input in a simulation model that then calculates the corresponding CO2 according to the NEDC test protocol. A dedicated vehicle simulation model (CO2MPAS) was developed for the purpose and is currently used for the type-approval of new vehicles in Europe. The development specifications of CO2MPAS were challenging, as it had to be highly accurate, exhibit fast operation, and function with a limited number of input data. This paper presents the development principles and process followed, details of the physical models employed in CO2MPAS, and provides information regarding its accuracy, validity and in use operation. CO2MPAS achieves low errors in the prediction of the NEDC cycle that in the controlled sample used for its development are of the order of 1% with a standard deviation of 3%, while the respective in-use numbers are of the order of 1.5% and 5%. In parallel, random sampling and testing of a 10% of the type-approved vehicles also occurs in order to guarantee the quality of the CO2MPAS results and the validity of the process. It is concluded that CO2MPAS can be used to accurately estimate emissions of conventional vehicles within a ±4% accuracy range, even when limited input data are available. In addition, the in-use data analyzed suggest that the use of the tool enables the certification of about 2/3 of the new vehicle models without the need of additional experimental tests. This is an important achievement as it reduces the costs and time necessary to certify light-duty vehicle CO2 emissions during the transitional period. Finally, it can be concluded that the use of CO2MPAS does not affect the declared CO2 emissions of vehicles over NEDC conditions.JRC.C.4-Sustainable Transpor

From lab-to-road & vice-versa: Using a simulation-based approach for predicting real-world CO2 emissions

CO2 emissions of light-duty vehicles are certified over standardised, laboratory-based conditions and reported to the consumers. Such tests reflect specific operating conditions that differ from what an individual driver experiences. Vehicle simulation can bridge the gap and help provide customised, vehicle and trip-specific values. This study investigates the potential of using a simulation-based approach for calculating CO2 emissions over real-world operation, when limited information and test-data are available. The methodology introduced in the European vehicle certification regulation since 2017 is used as a basis. Seven vehicles were tested over multiple on-road trips and in some cases on a chassis dyno. First, the analysis focused on the accuracy of the simulations when only limited information for the vehicle and its components are used. Subsequently, the model was calibrated on test data. The first case presented an error between 1.0% and 4.4% depending on the test, while the standard deviation was 10.0%. When using WLTP for calibration, the average error dropped to 2.9% to 0.2%, and the standard deviation decreased to 2.0%. When calibrating over on-road tests, the average error was 0.7% for the on-road tests and 4.5% for the WLTP.JRC.C.4-Sustainable Transpor

Understanding the origins and variability of the fuel consumption gap: lessons learned from laboratory tests and a real-driving campaign

Background: Divergence in fuel consumption (FC) between the type-approval tests and real-world driving trips, known also as the FC gap, is a well-known issue and Europe is preparing the field for tackling it. The present study focuses on the monitoring of the FC of a single vehicle throughout 1 year with 20 different drivers and almost 14,000 km driven with the aim to analyze and quantify the true intrinsic variability in the FC gap coming from environmental and traffic conditions and driving factors. In addition, the regression model has been developed to evaluate the importance of these different factors on the FC gap’s variability. Results: The 1-year FC gap measured in this study was 29% while driver’s averages were in the range from 16 to 106%. The regression model developed had R2 equal to 90.4 meaning that more than 90% of the FC gap’s variance can be explained with this model and factors measured in this study. The results of the model showed that among all factors analyzed the highest contribution in the FC gap’s variance is coming from the average vehicle speed (16.6%), followed by the road grade (13.4%), and trip distance (10.1%). Indeed, the highest FC gaps are measured when the average vehicle speeds were below 20 km/h, the average distance-weighted road grades above 1%, and the trip distances below 5 km. In addition, the impact of driver factors is not negligible (25%) and the highest FC gap is measured for the trips where average positive acceleration was higher than 0.7 m/s2 (indicating aggressive driving) and the electric power demand higher than 800 W. Conclusions: The future lifetime on-board fuel consumption reporting is a crucial instrument that will allow the monitoring of the evolution of the FC gap and ensuring that it does not increase over time. The analysis presented in this study is a basis for setting up a more detailed and refined prediction model, which could assist the European Commission in closely monitoring the gap and the underlying factors generating it.JRC.C.4-Sustainable Transpor

Is prolonged infusion of piperacillin/tazobactam and meropenem in critically ill patients associated with improved pharmacokinetic/pharmacodynamic and patient outcomes? An observation from the Defining Antibiotic Levels in Intensive care unit patients (DALI) cohort

Objectives: We utilized the database of the Defining Antibiotic Levels in Intensive care unit patients (DALI) study to statistically compare the pharmacokinetic/pharmacodynamic and clinical outcomes between prolonged- infusion and intermittent-bolus dosing of piperacillin/tazobactam and meropenem in critically ill patients using inclusion criteria similar to those used in previous prospective studies. Methods: This was a post hoc analysis of a prospective, multicentre pharmacokinetic point-prevalence study (DALI), which recruited a large cohort of critically ill patients from 68 ICUs across 10 countries. Results: Of the 211 patients receiving piperacillin/tazobactam and meropenem in the DALI study, 182 met inclusion criteria. Overall, 89.0% (162/182) of patients achieved the most conservative target of 50% fT 65MIC (time over which unbound or free drug concentration remains above the MIC). Decreasing creatinine clearance and the use of prolonged infusion significantly increased the PTA for most pharmacokinetic/pharmacodynamic targets. In the subgroup of patients who had respiratory infection, patients receiving \u3b2-lactams via prolonged infusion demonstrated significantly better 30 day survival when compared with intermittent-bolus patients [86.2% (25/29) versus 56.7% (17/30); P=0.012]. Additionally, in patients with a SOFA score of 65 9, administration by prolonged infusion compared with intermittent-bolus dosing demonstrated significantly better clinical cure [73.3% (11/15) versus 35.0% (7/20); P=0.035] and survival rates [73.3% (11/15) versus 25.0% (5/20); P=0.025]. Conclusions: Analysis of this large dataset has provided additional data on the niche benefits of administration of piperacillin/tazobactam and meropenem by prolonged infusion in critically ill patients, particularly for patients with respiratory infection

Prospective observational cohort study on grading the severity of postoperative complications in global surgery research

Background The Clavien–Dindo classification is perhaps the most widely used approach for reporting postoperative complications in clinical trials. This system classifies complication severity by the treatment provided. However, it is unclear whether the Clavien–Dindo system can be used internationally in studies across differing healthcare systems in high- (HICs) and low- and middle-income countries (LMICs). Methods This was a secondary analysis of the International Surgical Outcomes Study (ISOS), a prospective observational cohort study of elective surgery in adults. Data collection occurred over a 7-day period. Severity of complications was graded using Clavien–Dindo and the simpler ISOS grading (mild, moderate or severe, based on guided investigator judgement). Severity grading was compared using the intraclass correlation coefficient (ICC). Data are presented as frequencies and ICC values (with 95 per cent c.i.). The analysis was stratified by income status of the country, comparing HICs with LMICs. Results A total of 44 814 patients were recruited from 474 hospitals in 27 countries (19 HICs and 8 LMICs). Some 7508 patients (16·8 per cent) experienced at least one postoperative complication, equivalent to 11 664 complications in total. Using the ISOS classification, 5504 of 11 664 complications (47·2 per cent) were graded as mild, 4244 (36·4 per cent) as moderate and 1916 (16·4 per cent) as severe. Using Clavien–Dindo, 6781 of 11 664 complications (58·1 per cent) were graded as I or II, 1740 (14·9 per cent) as III, 2408 (20·6 per cent) as IV and 735 (6·3 per cent) as V. Agreement between classification systems was poor overall (ICC 0·41, 95 per cent c.i. 0·20 to 0·55), and in LMICs (ICC 0·23, 0·05 to 0·38) and HICs (ICC 0·46, 0·25 to 0·59). Conclusion Caution is recommended when using a treatment approach to grade complications in global surgery studies, as this may introduce bias unintentionally