Driven by good ideas

ZF Friedrichshafen AG is one of the world’s largest automotive suppliers. The company’s success story began over 100 years ago with the manufacture of gears and gearboxes. Today, its service portfolio encompasses a broad range of expertise in sustainable mobility technology. M&P is adding another sustainable cog to the wheel – through a company-wide energy efficiency initiative.

Proactively identifying energy-saving potential

ZF is a highly innovative and versatile technology company in which many ‘cogs’ – not only in its products but also throughout the entire corporate and site network – must mesh perfectly. We are therefore all the more delighted that M&P has also been a well-fitting ‘cog’ at ZF since 2020. In addition to providing consultancy support for the reorganisation of FM processes, we have been supporting a company-wide energy efficiency initiative for the past two years: the Saving Initiative Energy was launched by ZF’s energy managers to identify and implement energy-saving potential.

The initiative is not an end in itself. Rather, it provides specific support for ZF’s sustainability efforts. The company has set itself the goal of becoming climate-neutral by 2040 at the latest – ten years earlier than required by the EU.

“Sustainability is an integral part of the Group’s strategy. The overarching aim is to reconcile society’s mobility needs with the requirements of a healthy ecosystem. We must ensure that all our activities respect its limits whilst at the same time leading to sustainable and future-proof solutions. That is why ZF has drawn up a climate strategy: ZF aims to be climate-neutral by 2040. This means that by then, none of ZF’s sites will generate CO₂ emissions, either through on-site generation or through the purchase of electricity.” Wolf-Henning Scheider, CEO of ZF

To achieve these ambitious targets, the measures in energy efficiency consultancy and the sustainability approaches specific to the production sites are interlinked.

Viewed from a bird’s-eye perspective, the mostly identical pinions are arranged in an interlocking sequence.

Efficiency

Energy saving is the first key point. Energy that is not required in the first place results in no energy consumption, no CO₂ emissions and no costs. The potential for savings in our projects ranges from 5–30 %, depending on the site, sector and the success of previous optimisation efforts.

Substitution

Often underestimated or overlooked: due to differing areas of responsibility, departments and areas of expertise, ‘cogs’ often do not mesh together optimally. This gives rise to opportunities for substitution. In an industrial context, we encounter highly energy-intensive processing or manufacturing steps. Either energy (in the form of waste heat) is released by a thermal combustion process, or high-grade electrical energy is converted into heat through friction during mechanical processing.

By adopting a systems-based approach and, where appropriate, utilising physically advantageous effects – for example, through a heat pump – these losses can be harnessed to replace the energy required for heating or cooling buildings. In some cases, it is even possible to use waste heat to generate electricity via an ORC process.

Focus on heat generators

Our experts analyse the heat generators used in ZF’s production processes, offer tailor-made alternatives and pave the way for CO₂-neutral operations.

In traditional heating processes, the focus is usually solely on temperature and output. In ZF’s melting processes, however, other factors play a key role: heating time, type of heat transfer (radiation/convection), mobility, size, the geometry of the melting furnaces and their integration into existing processes.

Hardening furnaces in Friedrichshafen
Several gas burners, distributed throughout the furnace, currently supply the thermal energy required for the desired hardening process. Steel tubes in the burners, through which hot gas flows, transfer heat into the furnace atmosphere. Our energy experts’ solution for decarbonisation: the steel tubes remain in place. The gas burners, however, are replaced by electric heating elements powered by green electricity. The result: zero CO₂ emissions during hardening and up to 25% higher energy efficiency.

Nitrocarburising furnaces in Friedrichshafen
Although the furnaces are already partially electrically heated, natural gas is still being used during the transition phase: ammonia produced during the process must be thermally decomposed to comply with environmentally friendly emission limits. Until now, this has been handled by a gas burner fitted to the furnace’s exhaust pipe. In future, an electric annular gap burner will take over this task – powered by renewable electricity and more energy-efficient.

Melting furnaces in Nuremberg
At the Nuremberg site, a large volume of aluminium ingots and recycled material is completely remelted. To keep investment costs low, the existing melting furnaces are to continue to be used. Electric, resistance-heated crucible furnaces cannot be used as an alternative. They do not have the required power density.

Our experts have found the solution at the ‘Centre for Climate-Neutral Melting’ at the Technical University of Freiberg. Researchers there have developed a ‘plasma burner’ that can be used in the same way as a gas burner.

With the aid of an induction coil, it generates temperatures of up to 3,000 °C and can be retrofitted in a modular fashion. The manufacturer TPS has brought the technology to market readiness. As part of the implementation of our transformation concept, the next steps were defined in collaboration with TPS and ZF, including the expansion of the electrical connection on the company premises.

Generation/Procurement

Following efficiency optimisation and the utilisation of energy flows with losses, one question remains: how should we approach energy procurement? Where favourable conditions exist, opportunities for on-site energy generation are available, depending on individual and regional circumstances. These may include well-known technologies such as photovoltaic or wind power systems, but also more ambitious, future-oriented technologies such as PVT modules, pyrolysis or fuel cells.

For the remaining energy to be procured, we recommend renewable energy sources, which – at least in Germany – will become more widely available in the coming years, driven by political and societal demand.

Against the backdrop of long-term CO₂ reduction targets, the technical requirements of tomorrow should already be taken into account today in all new technical investments and replacement projects. We assist our clients by providing them with a technical roadmap featuring a bespoke CO₂ reduction target for the next 5–10 years.

Financial sustainability boosters

At ZF, M&P’s experts have so far provided valuable guidance on improving energy efficiency, substitution and on-site generation at over 15 sites in Germany, other European countries, Brazil and the USA. Plans are in place to continue the initiative on a similar scale in 2022.

In addition to making valuable contributions to the company’s objectives and reducing energy costs, such initiatives can also lead to savings on maintenance or investment costs. These savings can be utilised to provide additional funding for sustainability measures.

Another type of sustainability booster is the wide range of funding opportunities that the German government offers to the industrial sector. For example, if plant equipment in need of refurbishment is not replaced on a ‘one-for-one’ basis but is instead integrated using innovative concepts that utilise waste heat from production, or if traditional approaches are abandoned in favour of the transition from fossil fuels to renewable energy sources, then these projects can be subsidised with up to 50 per cent of the investment costs with the help of M&P’s sustainability and funding experts.

Savings, substitution, generation, funding: with every idea, we are guided by the aim of ensuring that the cogs mesh perfectly with plant managers, engineers, energy and environmental managers, and many employees at ZF.

The energy efficiency measures implemented by ZF and M&P mesh perfectly at SI Energy.

Images: © ZF Friedrichshafen AG