Guest blog: A digital twin approach to embodied carbon calculations, by Glen Worrall, Bentley Systems

A digital twin approach to embodied carbon calculations 

Glen Worrall, Bentley Systems

This article considers how to use the DT Toolkit roadmap to deliver a digital twin suitable for embodied carbon reporting. 

The requirement for a reduction in everyone’s carbon footprint can have a wide-ranging net when you consider the many “carbon” interactions we have in any given day. 

However, the latency of any transaction tends to affect the ability for carbon teams to have any influence on the design or materials used that can materially impact an assets carbon footprint. 

The digital twin mindset means that we can ensure our digital model is as close to the physical model as possible, but also can be interrogated quickly and easily. 

Going digital is a common theme, but the effectiveness of this must come from an increase in our targeted goals. The following process may be aligned with embodied carbon workflows but can just as easily be applied to any process that utilises the digital twin framework.

Why...  and what is it for? 

We require a digital twin to ensure the standardisation of embodied carbon reporting, which will be effective if we can reduce the embodied carbon calculation cycle from two weeks to instant. We also aim to make the report accessible by all project team members to ensure they are aware of how their decisions can make an impact upon the assets embodied carbon. 

The digital twin must be fed from current working practices and will remove the duplication of any data. This is an interesting problem that surfaces many times and generally conflicts with ISO 19650 processes,  i.e. while we want to access SHARED / PUBLISHED information we do not want to access WIP information and we do not want to access source information using a variety of tools. 

There are many ways we can use standards to enable access to the information and while visualising the result should be seen as part of the enhancements, the federation of external sources is not as straightforward as one would imagine. 

Carbon Calculators enable smart material selection

What information do we need and what data do we have? 

A simple question such as ‘how much concrete is in my model’ unfortunately has a very complex process in obtaining a result and one which costing, construction and carbon teams must answer on a regular basis. The definition of the term concrete is not as simple as it should be with different grades, but standards such as UNICLASS assist and help us locate those elements that will materially affect our embodied carbon total. Even the standardisation of units between the teams that report environmental product declarations and the teams that build engineering models is challenging. However, there are many unit conversion libraries which allow us to utilise tonnes, meters squared or cubic yards.

Standards such as Uniclass assist in developing industry processes 

Who will do what? 

This is interesting as most teams think that digital twins will remove the task. However, there is still a trade-off that must happen by carbon teams. Are we locally sourcing or cost restrained? This is part of the project planning that does impact the ability to be carbon zero. As long as make the task the sole focus and remove the requirement for finding data and presenting results for the project team, there should be a positive impact on the desired outcomes. We need the carbon teams to focus on effective material selection not being data wizards. 

What does the data tell us? 

The key here is that the results should be accurate, timely and effective. Improving the latency of the carbon reporting needs to have an impact that sees the reduction of the embodied carbon for all infrastructure. The data should show the reduction but also how complete the calculation is. An ISO 19650 workflow may release data which is not suitable, i.e. is the volume of a steel vessel really what we want to track or is it the volume of the shell of the vessel. This information must be transparent and especially when content is missing which will materially impact the global warming potential, i.e. what is the factor for the MEP systems in a building which may not be modelled for the next six months? 

Information Accessibility should be a key value proposition 

How are we doing? 

Like all infrastructure projects, the project is an evolving twin. Further as we move into construction what processes are in place to ensure the as-built embodied carbon matches the as-designed embodied carbon? There are plenty of processes in place to ensure the as-built asset matches the engineering requirements, but where was a different material used, how did the construction process impact the actual embodied carbon for an asset. What happens in 12 years’ time or after the first maintenance window.  This is information which we need to ensure that carbon and whole life costs align with our expectations. 

Conclusion 

Regardless of our outcome, a framework for our process and data requirements should lead us to a positive outcome. Further, the ability to identify the preferred outcomes allows us to identify those parts of the process that cannot meet requirements or can be improved. 

Glen Worrall is a member of the DT Hub Community Council and Director of Digital Integration at Bentley Systems. Contact Glen via the DT Hub.