Sustainable surface technologies: CO2 is the currency of the future

Sustainable surface technologies can make a significant contribution to the decarbonization of industry - and are increasingly becoming a decisive competitive factor, especially for small and medium-sized surface treatment and electroplating companies. More and more industrial customers are demanding proof of their carbon footprint, and banks are evaluating sustainability as a key risk and decision-making criterion. The article highlights current challenges and shows in a practical way how innovative coatings, processes and the Fraunhofer IST support companies in reducing emissions and achieving climate targets.

Our economic activities are endangering the stability of our planet. This was the conclusion reached back in 2009 by a group of international scientists led by Johan Rockström from the Stockholm Resilience Center, who defined a safe operating space for humanity in their publication based on the concept of "planetary boundaries" [1]. According to the updated version from 2023, six out of nine planetary boundaries have been exceeded today [2].

One of these six exceeded limits describes climate change, which is attributable to greenhouse gas emissions [3]. Economic players are reacting to this development. Regulatory requirements and voluntary commitments are prompting corporations and large companies in particular to align their business processes with the requirements of the Paris Climate Change Conference. As a large proportion of emissions in many industries originate from the supply chain, the focus is shifting to reducing emissions along the entire value chain.

Surface processes influence the carbon footprint both directly, for example through energy consumption during production, and indirectly by improving the durability and energy consumption of products during the use phase. The carbon footprint of surfaces is therefore becoming a risk factor - or an opportunity to stand out from the competition. Innovative surfaces are often a prerequisite for the sustainable design of industrial processes and enable key technologies for the energy transition. This opens up new economic prospects for the industry.

Fig. 1: Exemplary emission trajectories with CO2 emission budgets - Stefan Rahmstorf, 2021 [4]

Greenhouse gas emissions and their effects

Climate change is caused by the emission of greenhouse gases such as carbon dioxide (_CO2), methane (_CH4) and nitrous oxide (_N2O)._CO2 has the greatest absolute impact on global warming. The transition to an economy with reduced and ultimately zero greenhouse gas emissions is therefore also referred to as decarbonization.

As the Intergovernmental Panel for Climate Change (IPCC) outlines in its sixth assessment report from 2023, climate change is already having a significant negative impact on the availability of basic resources such as water, food and health worldwide. It also increases the likelihood of extreme weather events occurring and thus damages society's prosperity [3]. In order to manage decarbonization, two factors must be taken into account: First, greenhouse gas emissions must be reduced to a level that corresponds to a 1.5°C target. And secondly, the reduction in emissions must take place within a short period of time. If the reduction is delayed by a few years, greenhouse gases will continue to accumulate. In order to limit global warming to a certain temperature and avoid ecological tipping points, an even more drastic reduction is then necessary (see Fig. 1).

_{CO2 management}: corporate and product carbon footprint

Greenhouse gas emissions must therefore also be reduced in industry - and as quickly as possible. As a first step, companies should develop an understanding of their most important emission drivers. The greenhouse gas emissions of economic activities can be viewed from different perspectives. Two common standards are the Corporate Carbon Footprint (CCF) and the Product Carbon Footprint (PCF), i.e. the carbon footprint of the company and the product footprint.

Both are suitable for managing decarbonization in the company in a targeted manner. All relevant greenhouse gases are converted into_{CO2 equivalents}.

" Sustainable surfaces are rapidly gaining in importance and becoming a competitive advantage "

CCF: Reducing emissions along the value chain

The Corporate Carbon Footprint quantifies greenhouse gas emissions at an organizational level. Greenhouse gas emissions are assigned to the categories Scope 1, Scope 2 or Scope 3 based on their type and origin in the value chain (see Fig. 2).

Fig. 2: Overview of emissions along the value chain according to the GHG Protocol - World Resources Institute and World Business Council for Sustainable Development, 2011 [5]

Scope 1 comprises direct emissions that originate from the company's own sources. Examples include emissions from company-owned vehicles or Fig. 3: Share of Scope 3 emissions in total emissions by industry sector - World Resources Institute, 2022 [6] from the combustion of fossil fuels in production facilities on the company premises. The company can influence these emissions directly.

Scope 2 refers to indirect emissions caused by the consumption of purchased energy. This can be purchased electricity, for example, but also district heating and cooling. These emissions can be contractually controlled. Finally, Scope 3 covers all other emissions along the company's value chain. This concerns upstream activities such as the manufacture of primary products and the transportation of goods, but also downstream activities such as the use of products by end consumers and waste treatment and disposal. Scope 3 emissions are therefore only partially under the control of the company.

Scope 3 emissions predominate in most industrial sectors (see Fig. 3). Accordingly, reducing them is particularly important for companies.

In Germany, well over 250 companies have set themselves a science-based target with a Scope 3 reduction target by 2025 in accordance with the Paris Agreement [7]. Companies that pursue such targets use their influence on the supply chain or switch to more sustainable suppliers if necessary. Surface companies that do not have a direct contractual relationship with large companies are also increasingly confronted with requirements as a result. Sustainable surfaces are therefore rapidly gaining in importance and becoming a competitive advantage. The question remains as to how exactly a surface can be made more sustainable. The perspective of the product carbon footprint is a good way to do this.

PCF: Understanding product systems and taking action

Compared to the corporate carbon footprint, which looks at the organizational level, the product carbon footprint examines the greenhouse gas emissions of a product system, expressed as_{CO2 equivalents} and based on a life cycle assessment [8]. As part of this life cycle assessment, all climate-relevant emissions, from raw material extraction to disposal or reuse, are quantified and converted into_{CO2 equivalents} as part of the impact assessment. This creates transparency about the greenhouse gas hotspots of the product system.

The Sustainability Management and Life Cycle Engineering department of the Fraunhofer Institute for Surface Engineering and Thin Films IST supports industrial customers with scientifically sound analyses and many years of expertise in determining their product carbon footprints and identifying product-specific emission hotspots. In addition, the Fraunhofer IST is developing a tool with which customers will be able to evaluate their own upstream and downstream processes in terms of their_{carbon footprint}. On this basis, targeted measures for holistic process and product optimization will be derived; regular updates of the PCF will make progress measurable and enable effective follow-up control. In this way, the Fraunhofer IST uses its extensive expertise in coating and surface technology to support industrial companies in sustainably improving their_{carbon footprint}.

How surface treatment companies save their own emissions

One direct way to reduce the product carbon footprint in the surface treatment sector is to optimize the application or treatment process by increasing the use of renewable energy or improving energy and resource efficiency. Options for adaptation range from technical building equipment and the replacement of individual machines for surface processes to the use of innovative processes and the recycling of materials used.

The medium-sized company Lohngalvanik Moosbach & Kanne GmbH from Solingen has been committed to reducing energy consumption and_{CO2 emissions} since 2015. With measures such as the installation of photovoltaic systems, the replacement of rectifiers, heat recovery from exhaust air and the use of a combined heat and power plant, the company was able to achieve annual_{CO2 savings} of 205 tons between 2015 and 2021 [9].

Other companies rely on adapted processes: Wilhelm Bauer GmbH & Co KG from Hanover replaced lead anodes with platinized titanium anodes and saved around 10% of the energy costs required in this process step thanks to the improved conductivity of the platinum coating [10]. The_{CO2 balance} was optimized accordingly.

The Fraunhofer IST offers innovative solutions in the field of sustainable process development and management. Electroplating technology in particular has a high potential for increasing energy and resource efficiency, which contributes to the reduction of greenhouse gas emissions. The starting point is automated data acquisition and processing, which enables production processes to be mapped digitally. Current projects are developing data-based real-time condition monitoring with the aim of regulating and optimizing processes based on AI.

Surfaces decarbonize value chains

Sustainable surfaces also enable other companies to reduce greenhouse gas emissions and thus have an indirect impact on the carbon footprint along the entire value chain. This mechanism is becoming increasingly important as surfaces often influence emissions in the use and end-of-life phase of products.

One approach is to enable a circular economy for other materials through innovative surface technologies. These include, for example, laser and plasma technologies used at the Fraunhofer IST, which specifically remove coatings in order to prepare the treated plastic components for repair or recycling.

Improved surface and product properties through galvanically applied coatings can also contribute to decarbonization. These improvements can represent both longer durability through reduced corrosion or increased wear resistance, but also efficiency improvements through reduced mechanical friction due to treated surfaces.

Last but not least, galvanic processes are an important prerequisite for innovative renewable energy systems. Fraunhofer ISE in Freiburg has developed an electroplating process in which copper is used instead of silver for the conductor tracks of heterojunction solar cells. These solar cells, which are highly efficient and have a low_{CO2 footprint}, can be produced more cheaply and independently by replacing silver with the more readily available raw material [11]. Even modern offshore wind turbines could hardly withstand years of stress without corrosion-resistant surfaces from electroplating.

Outlook: Framework conditions and trends

Binding climate protection laws such as the European Climate Law and the German Climate Protection Act aim to achieve climate neutrality in 25 and 20 years respectively. It can be assumed that the_{CO2 price} in EU emissions trading will rise significantly in the medium term and make greenhouse gas-intensive processes increasingly unattractive. The expansion of non-financial reporting at EU level influences other economic framework conditions. The European Commission estimates that 7-8% of annual GDP must flow into green investments in order to achieve the sustainability targets [12]. Capital flows are therefore being directed towards companies that operate sustainably - this has so far applied in particular to corporations and large companies. In the foreseeable future, however, carbon-intensive business practices will also pose a risk for financiers of smaller companies.

Forecasts and current developments indicate that the importance of sustainable surface technologies will continue to increase over the next five to ten years. Companies that invest in appropriate solutions at an early stage will position themselves advantageously with regard to new market requirements, regulatory requirements and the expectations of customers and investors. In addition to the ecological effects, economic potential can also be tapped, for example through energy savings, improved access to markets and a stronger reputation.

Sustainability as a success factor in surface technology

Sustainable surfaces are key components of decarbonization in the industry. They reduce emissions through more efficient processes and renewable energies and enable additional savings along the value chain, for example through longevity, recycling and improved product properties.

The Fraunhofer IST supports companies - from determining the product carbon footprint and identifying potential savings to developing and implementing innovative, sustainable surface technologies.

The article is based on a presentation at the Surface Days in Leipzig 2024.

Literature
[1] Johan Rockström et al (2009). A Safe Operating Space for Humanity. Nature 461 (7263): 472-75. https://doi.org/10.1038/461472a
[2] Katherine Richardson et al (2023). Earth beyond six of nine planetary boundaries. Sci. Adv. 9, eadh2458. DOI: 10.1126/sciadv.adh2458
[3] IPCC (2023): Summary for Policymakers. In: Climate Change 2023: Synthesis Report. IPCC, Geneva, Switzerland, pp. 1-34, doi: 10.59327/IPCC/AR6-9789291691647.001
[4] Stefan Rahmstorf (2021). Two graphs show the path to 1.5 degrees. https://scilogs.spektrum.de/klimalounge/zwei-grafiken-zeigen-den-weg-zu-15-grad/?utm_source=rss&utm_medium=rss&utm_campaign=zwei-grafiken-zeigen-den-weg-zu-15-grad
[5] World Resources Institute and World Business Council for Sustainable Development (2011). Corporate Value Chain (Scope 3) Accounting and Reporting Standard. https://ghgprotocol.org/sites/default/files/standards/Corporate-Value-Chain-Accounting-Reporing-Standard_041613_2.pdf
[6] World Resources Institute (2022). Trends Show Companies Are Ready for Scope 3 Reporting with US Climate Disclosure Rule. https://www.wri.org/update/trends-show-companies-are-ready-scope-3-reporting-us-climate-disclosure-rule
[7] Science Based Targets Initiative (2025). Target Dashboard. https://sciencebasedtargets.org/target-dashboard
[8] German Institute for Standardization e.V. (DIN). (2019). Greenhouse gases - Carbon footprint of products - Requirements and guidelines for quantification (ISO 14067:2018). Berlin: Beuth Verlag.
[9] Magazine for surface technology. How Moosbach is implementing the Green Deal. https://oberflaeche.de/wissen/themen/galvanisieren/default-024628913f
[10] Magazine for surface technology, issue 4 | 2024, p. 42-44.
[11] Galvanotechnik, issue 12 | 2022, p. 1632 - 1634.
[12] EU Platform on Sustainable Finance (2025). Financing a Clean and Competitive Transition - Monitoring Capital Flows to Sustainable Investments - final report