Reducing the carbon footprint - and doing so consistently along the entire value chain of a vehicle - is currently one of the most important tasks in the automotive industry. In our series "Facets of Sustainability", we shed light on how Daimler anchors sustainability in all phases of the vehicle's life. In the spotlight today: CO₂ emissions during the use phase.
Mercedes-Benz is accelerating the transformation towards a zero-emission future: by as soon as 2025, all new passenger car vehicle architectures will be purely electric. The all-electric luxury saloon EQS is the first trailblazing flagship of this new era. The brand is currently developing the VISION EQXX, an electric vehicle with a real-world range of more than 1000 kilometres and the goal of achieving a single-digit consumption value for kilowatt hours per 100 kilometres at normal speed on the motorway.
Daimler Trucks & Buses is also consistently following the path to CO₂-free transport and is focusing on the development of innovative battery- and fuel-cell-powered vehicles. With the series-produced, fully electric Mercedes-Benz eCitaro, the company has been offering a solution for locally emission-free public transport since 2018. The all-electric city bus is already in use in a solo version and, since 2021, also as an articulated bus variant in numerous European cities. Battery technology is under continuous development with the aim of being able to meet the requirements of all applications, especially with regard to the driving range. Another example is the eActros, which had its world première on 30 June 2021: together with the FUSO eCanter, it will provide locally emission-free urban distribution transport in Europe in the future. As far as CO₂-neutral long-distance haulage is concerned, Daimler is focusing on the battery-electric eActros LongHaul, which is to be ready for series production by 2024. This vehicle will cover about 500 kilometres on one battery charge. In addition, the innovative GenH2 truck will set new standards in the future. It will achieve a range of 1000 kilometres and more using fuel cells and liquid hydrogen.
But it is not the drive alone that determines the efficiency of the vehicles. In addition to weight, other factors such as aerodynamics, shape, frontal area and rolling resistance of the tyres have an impact on the overall eco balance. Climate control and thermal management, as well as the power supply for the on-board electrical system and comfort features, also have an influence on efficiency.
And that's not all. As environmentally friendly as vehicles are designed to be, that alone is no guarantee of an optimal CO₂-footprint. The eco balance will only be perfect when drivers also use the sustainable vehicles in a sustainable way. This includes the topic of "charging": around 50 per cent of the carbon footprint of a battery electric vehicle is due to CO₂-emitting charging processes, based on the current EU electricity mix. To enable eco-friendly charging for customers of all Mercedes EQ models and all plug-in hybrid model variants, Mercedes-Benz has introduced Green Charging across Europe.
The way it works is relatively simple: over a certain period of time, the exact amount of electricity charged by all Mercedes-EQ vehicles via Mercedes me Charge is analysed. Subsequently, the defined quantity of high-quality green electricity guarantees of origin (1 MWh corresponds to one guarantee of origin) is provided by an external supplier. A guarantee of origin thus verifiably certifies the origin of the energy and serves as a kind of birth certificate for electricity from renewable energies. Along with the provision of green energy, driving style is a real eco-factor. The brands sporting the three-pointed star offer a wide range of support in this regard. An insight.
At the Mercedes-Benz Driving Training courses, customers have the opportunity to test Mercedes-Benz models away from public traffic zones without the limitations imposed by road traffic. In addition to tips on driving fun and safety, the driving trainers here offer training in efficient driving. For example, if you want to drive your electric car economically, you need to pay attention to a few special features. At high speeds of over 100km/h, the energy consumption increases disproportionately compared to a combustion engine. Very heavy braking should also be avoided, as part of the kinetic energy is converted in this process into heat and cannot therefore be recovered. More tips on energy-efficient driving with electric cars can be found here.
The ECO Assist system, which is an integral part of the electric vehicle, also helps to take sustainability aspects into direct consideration. For example, it uses a variety of data to indicate when the driver can take their foot off the accelerator pedal: the system determines whether the vehicle should continue to roll with the lowest possible driving resistance and thus 'glide'; or whether it should decelerate - and thereby recover energy for the battery (recuperation). ECO Assist stipulates the driving mode for what is deemed to be the most sensible choice of route, taking into account navigation data, speed regulations and traffic conditions.
Training for the transport sector
The ability to try out sustainable driving and experience the vehicles in all their facets is something that Mercedes-Benz offers not only in the passenger car context. Anyone wishing to drive into the future electrically with buses like the eCitaro city bus or the eActros truck can also benefit from the knowledge of the experienced instructors at the OMNIplus training courses and the truck training courses. Such courses serve to show how much influence the drivers' driving style can actually have: the consumption of trucks and buses can be reduced by up to 10 % through appropriate driving techniques.
The OMNIplus EcoTraining courses are part of a comprehensive advisory system that Daimler Buses has built up around the eCitaro. Through its overarching, in-house eMobility Consulting service, Daimler Buses supports transport operators in setting up the appropriate infrastructure for their respective electric city bus fleets. As part of their consulting services, the specialists determine which routes lend themselves best to e-mobility solutions, and help plan the infrastructure. They know how to access the grid operators and green electricity providers and can recommend the right charging technology. This significantly reduces the complexity of an e-mobility project for the customer. During the Eco Training course, the professionals show the drivers how to reconcile environmental friendliness and punctuality. And how drivers and passengers can reach their destination in a more comfortable, more environmentally friendly and safer way, while also experiencing less stress. Continuous driver evaluations are used as a means of realising sustainable savings potential.
Of course, an anticipatory driving style also plays a major role with respect to fuel consumption in trucks. Technical support for the driver is provided here by the cruise control and transmission control system Predictive Powertrain Control (PPC). This helps to avoid unnecessary braking, acceleration and gear shifting because it processes topography, road layout, traffic signs, speed limits and much more information in advance. This leads to fuel savings of up to five percent on average compared to vehicles that are not equipped with the system.
The MirrorCam system, which is used in the Actros and Aroc and replaces the conventional mirrors, also has a positive effect on the overall eco balance. The small streamlined camera arms on the roof frame were not only developed to give the driver optimised all-round visibility, but also reduce fuel consumption by around 1.5 % thanks to their optimised aerodynamics. The concave side deflectors on the cab also play their part here.