More and more car manufacturers are expanding their activities relating to sustainability. Small and large components of a passenger car are examined in detail, extensive life cycle assessments are carried out, and lengthy supply chains are analyzed. In our interview, Dr. Ulf Zillig from Mercedes-Benz discusses with ATZ about whether there is enough green electricity for all production plants and what steel and aluminum, or even coffee beans and bamboo, might be able to contribute.

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© Mercedes-Benz Group

Dr. Ulf Zillig (born in 1966) is Head of Group Research, Sustainability & RD Functions at Mercedes-Benz Group AG in Sindelfingen (Germany) since January 1, 2022. Zillig studied at TU Karlsruhe (Germany) and at Oxford University (United Kingdom). He received his PhD from ETH Zurich (Switzerland). After joining DaimlerChrysler AG in 1998 as a member of the company's International Management Associate Program, he took up his first post as an assistant to the Director of Development in the Mercedes-Benz Vans division. From 2001, he was Head of Development Documentation, and in 2004 was appointed Head of the Development Controlling, Planning and Process Design department and the Van Technology Center. He held further senior management positions in 2006 as Head of Department Lifecycle Management and in 2011 as Head of Strategy Development and Portfolio Management. From 2014, he was overall strategic project manager for the VS30, the Sprinter. Between 2018 and 2021, he was Head of Development and Product Development at Mercedes-Benz Vans and was responsible for global development. Here, he was also in charge of the conception of the new Sprinter and the VAN.EA platform.

ATZ _ Ulf Zillig, in March 2021, Mercedes- Benz announced that production at its own plants worldwide would become CO2-neutral from January 2022. Did it work and what is the situation today?

Zillig _ Since 2022, production at our own Mercedes-Benz plants has indeed been net carbon neutral. They obtain their electricity exclusively from renewable energy sources. In Germany, Mercedes- Benz relies on a mix of electricity generated from solar, wind, and hydroelectric power. And the special thing about it is that our electricity demand is met with green electricity from the grid that is guaranteed on a quarter hourly basis. In addition, we are committed to expanding the use of solar and wind power at our own plants. Mercedes-Benz is aiming to expand photovoltaic systems at our sites with a peak power of up to 140 MW by 2025. That is equivalent to 1,000,000 m² of new solar panels. A further focus of the company's energy strategy is the expansion of its energy portfolio to include wind energy from onshore and offshore wind farms. The new solar power systems and wind turbines will enable Mercedes-Benz to cover around 50 % of its entire electricity requirements in Germany in the future. The company intends to increase the share of renewable energy sources in the total energy requirements of its own production facilities to 70 % by 2030, not least by expanding local generation capacity. We aim to stop using fossil energy sources completely by 2039.

Is there enough electricity from renewable energy sources on the market for all of your plants? How do you calculate the balance: hourly or annually?

For our German plants, a large proportion of CO2-free electricity is generated in various power plants in Germany. These include part of a solar park with the size of 60 football pitches near Ingolstadt and nine wind farms. This intelligent mix is supplemented by electricity from flexible hydroelectric power plants. The generation of green electricity is synchronized with consumption patterns. This ensures that a supply with green electricity from the grid can be guaranteed on a quarter hourly basis. In many previous green power contracts, feed-in to the grid takes place purely on an annual balance basis. Mercedes-Benz is a pioneer in Germany with this green electricity concept. It enabled the construction of the new solar park without subsidies, as well as the continued operation of the wind turbines, which would otherwise have fallen out of subsidies under the Renewable Energy Sources Act (EEG) in 2021.

Let's turn from the production plants to the vehicles: How will you achieve the goal of a completely net CO2-neutral new vehicle fleet in 2039, as set out in your Ambition 2039 strategy? After all, that's eleven years earlier than is required by EU legislation.

With Ambition 2039, Mercedes-Benz is committed to making the entire fleet of new vehicles net carbon neutral along the entire value chain in less than 20 years. By the end of the decade, we aim to at least halve CO2 emissions per passenger car over the lifecycle compared to 2020 levels. The most important levers for this are the electrification of the vehicle fleet, charging with green energy, improving battery technology, and the extensive use of recycled materials and renewable energy sources in production. However, the transformation to electric mobility increases the energy demand in the upstream supply chain. For that reason, a holistic approach on the path to all-electric mobility also includes our suppliers. Together with our partners in the supply chain, we aim to implement effective climate protection measures. Our goal is to prevent, minimize or, as far as possible, eliminate potential environmental impacts along our supply chain. The starting point is to create transparency.

Your Vision EQXX research prototype has a range of more than 1000 km without recharging. At what points is this record being achieved at the expense of the environment?

We rely on the sustainable management of supply chains for our electric vehicle fleet. We consider the responsible use of raw materials right from the start and take a risk-based approach. Our goal is that our products only contain materials that have been minded and produced without violating human rights and environmental standards. We use a variety of measures and concepts for the sustainable management of our supply chain. These include the screening of suppliers, risk-based due diligence analyses, and sustainability training courses for suppliers. In addition to compliance with social standards and environmental requirements, we also achieve greater transparency in the supply chain as a result. What is more, Mercedes-Benz is making the Standard for Responsible Mining introduced by the Initiative for Responsible Mining Assurance (IRMA) a key criterion for supplier decisions and contracts in battery related raw material supply chains, and will only work with suppliers who comply with this standard. Moreover, the integration of recycled materials plays a vital role for our resource strategy. A pilot factory for the recycling of lithium-ion battery systems is being built on the site of the Mercedes-Benz plant in Kuppenheim. The process is expected to achieve a recovery rate of more than 96 %.

Rather than recycling, what speaks in favor of a second life for traction batteries?

Mercedes-Benz is taking a holistic approach to the circular economy of battery systems, taking three core issues into account: circular design, value retention, and closing the loop. During the development process, the company creates a concept for each vehicle model in which all components and materials are analyzed for their suitability in the context of a circular economy. Recycling of the raw materials used, such as lithium, nickel, and cobalt, is an integral part of this approach, and also begins with the design of the components themselves. Mercedes-Benz offers reconditioned batteries as replacement parts for all electric vehicles, in order to comply with the idea of a closed economic loop and to conserve resources. In addition, Mercedes-Benz has established a successful business model with stationary large-scale energy storages through its subsidiary Mercedes-Benz Energy. Batteries that can no longer be used in vehicles can continue to be used in a second-life storage system. Material recycling takes place at the end of a battery's life and is the key to closing the loop of recyclable materials.

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© Mercedes-Benz Group

“Mercedes-Benz will only work with suppliers for battery related raw materials who comply with the requirements of the Standard for Responsible Mining introduced by the Initiative for Responsible Mining Assurance (IRMA),” explains Zillig

Vegan leather alternatives in the doors of the EQXX are one thing, but how do you deal with the really heavy components in the car, such as the body, if you want to advance the overall process of conserving resources?

As batteries, steel, and aluminum are the biggest contributors to the CO2 footprint of vehicle production, Mercedes-Benz has set clear targets for reducing emissions. These include the decarbonization of focus materials, increased recycled content, and the use of renewable energies. For example, together with our suppliers, we are therefore working on decarbonizing our steel supply chain. Even today, we use steel with a greatly reduced CO2 footprint due to the use of recycled steel scrap. We are aiming to use more than 200,000 t of CO2-reduced steel a year from our European suppliers Salzgitter, Thyssenkrupp Steel, Voestalpine, Arvedi, SSAB, and H2 Green Steel in our press shops. Together with steel, aluminum is proportionally the most widely used material in many vehicles and is becoming increasingly important, especially in electric vehicles.

How can Mercedes-Benz further reduce CO2 emissions in the use of energy- intensive aluminum?

In Europe, at least one third of the aluminum we use in our upcoming electric model generation will be produced with renewable energy sources. Together with the Norwegian aluminum producer Hydro, we are going one step further: The first material from Norway with a CO2 reduction of almost 70 % compared to the European average and a minimum 25 % share of post-consumer scrap has already been tested and has been integrated into series production in the course of the year. By 2030, we want to reduce the aluminum footprint with Hydro by more than 90 % with the aid of further innovations.

Which other materials are you using to improve the ecological footprint, for example in the Concept CLA Class? Is the use of bamboo fibers even in crash-relevant structural components conceivable?

We are already using various recycled materials in our series-production vehicles. In the interior, for example, we offer various high-quality fabrics that are made from up to 100 % recycled PET. At the same time, we also use natural fibers and textiles in order to replace conventional oil-based plastics with renewable raw materials. Recently, we demonstrated some exciting material in our Concept CLA Class, which gives a preview of the upcoming Mercedes-Benz Modular Architecture (MMA) vehicle platform. This includes, for example, sustainably produced and processed leather that is tanned using plant-based tanning agents such as ones from coffee bean husks or chestnuts. The floor mats are woven from bamboo fiber and the door pockets are edged in a biotechnology- based silk-like fabric. We showed a completely new material on a trim element of the Concept CLA Class: a paper material made from recycled cellulose - with a 50/50 composition of recycled cellulose and hemp targeted for series production. It is a good example of how sustainability and luxury can go hand in hand.

The aim is to conserve resources and be more economical in the use of materials. What can we learn from nature and what is behind your BIONICAST digital approach?

At Mercedes-Benz, we have developed and established an innovative method called BIONICAST for the development of body components made of aluminum. In this new development process, structural cast parts made of aluminum are designed and implemented according to the principles of nature: Material is used only in those places where it is necessary for the structural function, for example to transfer or carry loads. Therefore, in addition to optimizing weight and saving material, this development method also helps to conserve resources. We demonstrated the potential of this innovative engineering process in the BIONEQXX Vision EQXX research prototype. Together with a single-part body segment, the BIONEQXX rear floor, we developed and implemented two damper domes and a bracket for the windshield wiper motor. The goal was not the sheer size of the components, but an optimal design for lightweight construction, efficiency and performance. In addition, the first BIONICAST components can already be found in series-production models: The EQS uses such a component for the seatbelt retractor. Starting with the upcoming MMA vehicle platform, we intend to use more of these components in series production. A variety of other components are currently being developed.

Ulf Zillig, thank you very much for this interesting interview.

You can read more of this interview in German language on our online portal at www.springerprofessional.de.