Maintenance-free circuit breakers with metal-graphene composites

Led by ABB, Graphene Flagship Spearhead Project Circuitbreakers investigates the use of metal-graphene composites to produce maintenance-free low voltage air circuit breakers – devices connected to the electrical distribution grid that open and close an electrical circuit during faults. 

We speak with ABB’s Research Team Manager, Santanu Singha, who is passionate about eco-design and circular economy applied to engineering and technology, to understand how the Circuitbreakers project can improve the life cycle’s sustainability of low voltage air circuit breakers. 

Which problems are you trying to solve? 

Circuit breakers need to be durable and robust. Today, the mechanical drive inside circuit breakers is lubricated with a grease solution, which tends to age with time and needs periodic maintenance. One of the ways to mitigate this problem is to develop and apply a very good, self-lubricating coating solution. We attempt to eliminate grease and use a metal-graphene composite to make the product last longer in the field.  

Why did you think about graphene? 

We have looked into graphene since 2016. From our internal testing and lab-scale investigations, we found that a small amount of graphene in a metal matrix can create a very good lubrication solution for mechanical problems. This is how we started our journey and over the years, we have expanded our investigations through numerous tests on different metallic surfaces, e.g., steel, copper, etc. We try to understand how the whole product will work in a practical system.  

Today we are at a stage where we are becoming increasingly confident about graphene as a promising material for mechanical lubrication. And that's why we have scaled up our intention, we aim to increase the technology readiness level and achieve successful applications. 

You mentioned that ABB is very committed to sustainability. Can you comment on that?  

Sustainability is becoming increasingly important in Europe. From an industrial perspective, the sustainability aspect of a product will be sort of the licence to operate in the European market. When we talk about sustainability, there are many different aspects to take into account, but one of the key areas that we are focusing on is the environmental impact that a product has during its entire lifecycle, from material sourcing to its usage and end of life.  

When introducing a new material into a product, we have to ensure that we are meeting the sustainability targets that we have set within the organisation and the sustainability and circular economy requirements defined by the European Commission. We do not want to bring in a material that increases carbon dioxide emissions: we want to ensure that the overall environmental impact is much lower compared to existing products.  

How does this apply to your target circuit breakers?  

We have seen from literature that the metal-graphene composite that we are targeting for our circuit breaker application provides tremendous value to improve the product’s sustainability. We will potentially have lower emissions in the upstream phases, when the raw materials are sourced and manufactured. Then, we are also eliminating service requirements during operations. Every maintenance and service activity requires travel, new materials and in some cases component replacement: all of these steps introduce CO₂ emissions. Therefore, we believe that our maintenance-free circuit breaker solution can contribute to saving emissions across different phases of the product’s life cycle.