Electronics CO2e Calculation Models
According to the WEEE forum, ewaste is the fastest growing waste stream in the world at 57.4 million tonnes, having grown some 21% in just the last five years. This will be of little surprise to anyone given the technology-focused world we all live in. Whilst demand for electronic goods continues to grow at these staggering rates, there is a hidden environmental cost that is being paid in the manufacture, use, and end of life disposal by providing us all with such products.
If we are being honest with ourselves, until recently, sustainable and environmentally sensitive electronics were not at the top of anyone’s list as a design criteria; if they were even on it at all!
Thankfully, the world has moved on and the awareness of what we are doing to our planet and environment has now elevated the impact to be the number one requirement for new designs. After all, our responsibility should start at the design stage, and we should not rely on future generations to deal with the problems we create today.
As environmentally responsible businesses, we need to have at our disposal a mechanism to enable us to compare and evaluate materials, modes of manufacture, and cost of disposal to best aid our research, and the implementation of new materials and processes going forwards.
In2tec dedicate a significant percentage of our engineering capacity to research activities for sustainable electronics development, and the need for a universal metric against which we can quantify advancements is paramount. As an engineer I, like all engineers, desire hard facts and metrics we can measure and qualify. This enables us to benchmark what we do and quantify the sustainable and environmental impact that our designs and products have. The key accepted metric we have available today is a measure of CO2e (carbon dioxide equivalent). It is used to compare the emissions from various greenhouse gases which are converted to an equivalent amount of carbon dioxide with the same global warming potential (GWP). Sounds simple enough.
The problem with this is that the accuracy of any calculation model is dependent on having enough real data on which it can be based. Without hard data the numbers produced are at best meaningless and at worst highly misleading.
Unfortunately, the electronics industry in general is lagging other disciplines (such as the plastics industry), and as such there is little quantified CO2e manufacturing data available! What we do know, at the end of the day it pretty much all boils down to the energy required for material harvesting, and manufacture from the raw materials through to final product. As a start to appreciating this, Stutz (et. al 2011/12) did some excellent work where they were able to relate CO2e to Dell servers.
Others have picked up on this research, such as that by Laura Talens Peiro (et. al), providing additional information relative to the environmental footprint of PCBs and PCBAs, if still based on large scale systems. Cross referencing these with other published data, and our own measured data of production processes, construction, and component makeup, have helped us form the basis of a model that allows us to make estimates for the CO2e contained in electronic PCBA assemblies across a range of materials, processes, and manufacturing.
This leads to a bit of a segue and passion of mine. One HUGE variance in any CO2e model output centres on where the materials, manufacture, and assembly occur. For example, energy in China has nearly five times the associated CO2e per kwh compared to the UK, due to power stations being generally coal fired compared to wind farms. As some 51% of all electronic components are made in China (up from 42% in 2016), this immediately has a significant impact on their embedded CO2e over which we have little or no control. This feeds into China contributing a staggering 29.18% share in the worlds CO2 emissions in 2021. By comparison the USA is 14.02% and the UK just 1.03%.
As leaders in electronics design and manufacture we need to embrace the development of a true circular economy driven not just through recycling of materials but also through the development of a second life economy for components and semi-conductors. Given that such high levels of CO2 are tied up in the manufacture of the electronic components and semi-conductors it will be obvious to all that these components, which contain significant embedded carbon, should not be wasted where they have significant life left in them.
Many components have 20+ years of viable life (manufacturers data) and yet we often bin devices after as little as 1.5 years with a market average of just 4.5 years (Quantum Lifecycle). Being able to reuse these components not only effectively offsets the CO2e in their second life (as there is no need to make new components), it also provides a potential revenue stream as now they have value as opposed to having a cost for their disposal. It’s outside of the scope of this blog, but at In2tec we are acutely aware of this and have in response developed materials and processes specifically to facilitate a circular economy for electronics, ReUSE® and ReCYCLE™.’
As we move forward and develop a greater understanding of what we as a PCBA industry develop and manufacture, it will be appreciated that many assumptions still must be made in generating any generic CO2e model. These are unavoidable, just so long as these are reasonable and justifiable.
However, to minimise this I call upon component, material, substrate, and PCB producers, all to look at their manufacturing to enable a greater understanding of the environmental impact of what they produce. Only then will we be able to see the full impact of what we have done, what we can do, and what impact our decisions, designs, and manufacturing processes have on the world around us.
Consequently, whilst any current model will be limited, it still has significant value in allowing us to benchmark differing production and manufacturing methodologies. To this end In2tec deliberately keep the modelling and calculations simple to minimise the volume of assumptions that must be made. To be honest, whilst we estimate an error variance of around 15% in truth this number could be far higher, as so many things are just unknown and unmeasured, especially around the manufacturing phase on the components and substrates.
What is clear is that whilst having absolute numbers in terms of tonnes of CO2e is great, (especially looking good for marketing), these numbers will always be subjective until one can define, measure, and quantify every step and element in a given PCB’s manufacture. The most real-world values are given in percentage terms as the same methodology and assumptions can be applied to both the before and after. Thus, stating a 65% reduction in CO2e is much more likely to have a higher degree of certainty than saying a reduction of 34 tonnes.