Do you know what a sustainable electronic product is? You probably already have an idea but not a well defined concept. But that’s OK, it turns out that it is not either a simple or well established definition in the electronics world. After all, as developers and designers our main focus, as we’ve been taught both at work and at university is to focus on the product specifications and characteristics itself, not how its components, performance, and end of life affects the environment and other people (unless you are actually designing a product with sustainability in mind from the beginning).
Sustainability in electronics can be both analyzed from a systems and a low level “design” perspective. It is worth knowing both as usual, however, as Developpa’s main focus is in helping the developer to successfully create his or her electronic product, this article will focus on what the developer needs to know to ensure the design can be classified as sustainable and you can then brag about it to the marketing department (they’ll love it).
What is sustainability in the electronics industry?
Sustainability in its broader sense just means to continue a defined behaviour indefinitely. Therefore in our case, we want to be able to produce and enjoy electronics indefinitely in our finite-resources planet
To make an electronic product sustainable, it has to take into consideration the following aspects:
Optimized embodied energy and low C02 footprint in its production and distribution
Embodied energy is understood as the amount of energy that was used to manufacture a particular product. A product is composed by parts, components and is manufactured by machines that require energy, also, the raw materials are transported to the factory and then the factory ships the final goods to the distributor (you can see how it all starts to add up). The analysis and quantification of all these processes are called a Life Cycle Assessment or EcoAudit. The objective of an LCA is to optimize the material selection, manufacturing process and transportation so the total embodied energy of the product is less. Before starting a product LCA, the boundaries and scope of the analysis need to be defined. For example, if you are using a raw material in your product, let’s say, some aluminum alloy for the product enclosure, it is easier to determine the origin of this material and the manufacturing techniques used by asking the supplier, however, if our product has another product inside (did anybody said Arduino, Raspberry Pi?) or a complex component, it is almost impossible to trace back or properly analyze such vast information.
According to the article “The monster footprint of digital technology” from Low Tech Magazine: “to produce a 2 gram microchip, 1.6 kilograms of fuel were needed. That means you need 800 kilograms of fuel to produce one kilogram of microchips, compared to 12 kilograms of fuel to produce one kilogram of computer… A gadget or a computer does not contain one kilogram of semiconductors – far from that. But, we don’t need a kilogram of microchips to ensure that the manufacturing phase will largely outweigh the usage phase. The embodied energy of the memory chip alone already exceeds the energy consumption of a laptop during its life expectancy of 3 years.” This dull but truthful reality means that whatever you do as a designer to improve the sustainability of the product following the current trends of manufacturing electronics will not be enough to actually balance out the energy used in the product manufacturing with the energy saved during its use. However, this should not discourage you and you should always aim to design with the lowest embodied energy possible. Then, as electronics designers and developers what can we do to reduce the embodied energy of a product? We can divide it into 3 different properties:
The main parameter to determine embodied energy for anything is weight, and components are not an exception. You can see in the attached table from the Embodied Energy and Off-Grid Lighting from the Lumina Project the embodied energy of each component per Kg: The EU Ecodesign Eco Report Tool also provides some values:
Looking at this information, then we can simply say that by selecting a lighter component, the embodied energy of the product will be less. However, the relationship is not always as direct. For components such as inductors, electrolytic capacitors, PCB size and connectors, this rule can be more or less safely applied since these components are not “complex” (in principle an inductor with less inductance and less max current than another one with more inductance and more max current is the length and thickness of the coil). For more complex components such as ICs and semiconductors, other factors such as the packaging and chip complexity come into play. Even for our inductor example, if the smaller inductor has a tiny plastic package that requires a specialized machine to manufacture it, then this option could have a bigger embodied energy.
Also, try to analyze it from a Systems perspective. Maybe it is better to have a smaller inductor with more embodied energy because then you can have a smaller PCB and smaller enclosure, therefore reducing the total product embodied energy.
Only interested in applying these guidelines to your design? Download the Design a Sustainable Circuit Guide
Privacy Notice: Your email address will not be shared and you will only receive relevant content. Zero Spam
Component package type
Surface Mount Device or Through Hole?
SMD components optimize the use of material since they are smaller than their THT counterparts, however, SMD components have an energy demanding manufacturing process (see video below from Yageo) where heat is applied many times and metals such as nickel and tin are used. This is not true for THT components as they have a purely mechanical manufacturing process and less added materials, however, THT components have long metal leads.
From a systems perspective, the use of SMD components will allow you to have a smaller PCB, thus reducing the embodied energy of the product.
Seems like there is no clear choice here, so the choice of component type will be probably determined by other design factors such as space and costs
Internal complexity of a component
This property applies mostly to semiconductors (diodes, transistors) and ICs. Components that have a casing such as MCU’s, logic gates, opamps, MOSFETs are mainly made of plastic, metal (copper/ aluminium) and Semiconductor Grade Si. According to the previous reference from the Lumina Project, the embodied energy of 1Kg of Semiconductor Grade Si is 35000 MJ. Even though most of the weight of the IC will come from the metals and plastic packaging, the semiconductor material will be responsible for most of the embodied energy of the component. This is an important point, meaning that the IC that has a bigger size or package is not necessarily the one with the highest embodied energy. For that, we need to dig deeper into the weight of the semiconductor part of the IC. Why is the semiconductor part of the IC responsible for most of the embodied energy? Simply because of all the energy required to manufacture and process this nano-metrical and highly complex component. Unfortunately, at the moment companies do not provide with information of how much weight of semiconductor material per IC they sell. It will be great if this information was included in the device datasheet, therefore the designer can take decisions upon this number. One way to approach this limitation is to contact the supplier directly and ask for this data so you can then evaluate different options.
Components and PCB manufacturing location
Think about the complex procurement and logistics necessary to buy different components from different countries and ship them into a PCB manufacturing plant and then that PCB has to be shipped somewhere else after production. Add on top of that all the fuel that is required for transportation and how it affects the environment. Also, think about what do manufacturers use to power their plants? Is it renewable energies or coal? Although these decisions of where to buy and manufacture the components and PCB are not normally made by the designer, it is worth knowing that these factors also contribute to the embodied energy of the final product. So, if you can, try to choose a closer location for manufacturing with respect to where the product is going to be sold, and ask the manufacturers for their energy sources. Companies such as Google and Apple have committed to only use suppliers and manufacturing facilities powered by renewable energies.
No hazardous materials for the environment and people
Because of ignorance or business profitability, some electronic components can have a certain concentration of materials that can be harmful to other human beings while a device is being manufactured or to the environment once the device is disposed of. The most common toxic materials are:
- Hexavalent Chromium
- Polybrominated Biphenyls (PBB)
- Polybrominated Diphenyl Ethers (PBDE)
- Bis(2-Ethylhexyl) phthalate (DEHP)
- Benzyl butyl phthalate (BBP)
- Dibutyl phthalate (DBP)
- Diisobutyl phthalate (DIBP)
Fortunately, the European Union has already taken a step forward back in 2006 and created the Restriction of Hazardous Substance Compliance (RoHS). This European Directive states that for an electronic product to be sold in Europe, this product must have less than a certain level of these hazardous materials, otherwise, I cannot be sold in the European market. Since this is an already well established requirement, it is easy for the designer to implement it. For example, you could do a search in DigiKey and tick the box “RoHS Compliant”: Otherwise, it should appear in the device datasheet:
These are the different type of minerals used in electronic components that have been extracted in countries such as the Democratic Republic of Congo and there is enough evidence to support that armed conflicts have been financed by the extraction of these minerals and that the miners extracting them are facing inhumane work conditions. The most commonly mined conflict minerals and their use in electronics are:
- Tin: soldering material
- Tungsten: old incandescent lights, IC heatsinks, arc welding electrodes
- Tantalum: high capacitance, small size capacitors and high-power resistors
- Gold: high quality conductor. Used in PCB pads, relay contacts, connectors and CPU pins
If as a designer you are required to use any of these minerals, it is your responsibility to the supplier for proof of conflict minerals compliance. This way you can assure that the components you are buying are not fueling a war somewhere else. Sometimes there is lack of transparency from the supplier regarding where they got their raw material from. In the future this issue can be addressed by Blockchain technology, thus assuring that the data presented to the end customer is the real one and has not been altered or modified along the way.
For an interactive explanation of Conflict minerals, watch the video below from the Enough Project:
Optimized use of energy while in use
This is an important parameter that not only concerns sustainability. It is true that by optimizing the use of energy of the device, less energy will be required to perform its function, therefore more efficient but also by performing this optimization you will have an overall better product. For example, if the product is battery powered then you can extend its battery life or even better reduce the size of the battery, lowering costs and reducing the embodied energy of the product. Everybody wins. The main parameters to optimize the use of energy in the device while in use are:
- Efficiency of electronics
- Optimized firmware
- Low power design
- Power management
There is a whole article dedicated to this topic. Please check it out here
Design to last
One of the main concerns for sustainability in the electronics industry is that some products life cycle is too fast. Take as an example the smartphone. The average lifespan is between 2-3 years, depending on the phone you got, if it was a high-end phone maybe even 4 years. The main reason a phone becomes obsolete is because the battery degrades and the new software makes the old hardware outdated. Back in the days, it was easy to change the battery of a device and roll back to previous software releases. If a product is designed so it makes its weak spots easily changeable or reparable, the product lifespan can be increased. When this happens then the embodied energy of the product becomes less important because the embodied energy of one product will be less than the one of two similar products. Is like buying a good pair of shoes for $50 that will last you 2 years instead of buying one pair of shoes for $35 that will only last you one year.
End of life potential
For the end users, a product will normally stop providing value and will be forgotten once they’ve decided it no longer serves its purpose and it is time to throw it away (dispose of it). For the designer, instead of seeing this lifespan process as linear, should try to visualize it as cyclical or at least a very long line with a few loops. Almost every electronic product have some sort of end of life potential. This means that after its initial intended use, the whole product or its parts can be used in one or many of the following ways:
Repaired and Reused
When some part of the product breaks and is then repaired you are instantly adding years to its lifespan. This is probably the best end of life potential a product can have as it doesn’t need any extra processing or manufacture. As a designer, you should aim to create a design where breakable parts can be easily accessed and changed. To achieve this in your design, conduct a weak spots analysis and determine the parts that are most likely to fail during the lifetime of the device. Having in mind this, make these components easily changeable by avoiding direct solder connections or tricky locations where possible. It could be useful as well to add some text to the PCB silkscreen layer to highlight this area. Then with this information tell the project manager that a structure needs to be created where users can access technical documents and are able to buy the spare parts. Or more realistically, to setup repairment hubs where people can take their electronics for repairment.
Downcycling means to give the product a different, less complex use compared to its original intended purpose. This is the second best option for an afterlife of a product because like repairing it, it doesn’t go into the waste stream and its lifespan is increased, therefore making the embodied energy less relevant. An example of downcycling with a modern mobile phone, could be that when the user decides to get a new phone because the hardware of the old phone does not have enough processing power and memory to handle modern applications, this old phone could get a “basic” and “lightweight” OS installed that only runs simple applications such as telephone, messaging and internet without any fancy graphics and animations. This phone could be then kept for emergencies or donated to low income countries where people cannot afford the newest and latest iPhone. However, downcycling does not have to be complex, it could simply mean using the product enclosure of let’s say, an old VHS perhaps, to store cutlery or socks.
Recycling is one of the main foundations of a circular economy. You keep the initial primary resource that you took from the earth cycling over and over again and ideally, many decades will pass until you have to throw it in a landfill. This concept applies to simple products such as glass beer bottles and tuna cans, however, for complex products, the recycling process becomes much harder. Think about the linear process of making a bolognese pasta: you cut all the vegetables, cook them with minced meat and then add some tomato sauce and finally the spaghetti. Now imagine that you have to reverse that process and recover all the raw materials, not as easy right? If we take our pasta analogy and compare it to an electronic product you will have parts that are easily separated, like the pasta from the sauce (the enclosure from the PCB) and the liquid sauce from the solid ingredients (big caps and coils from the PCB). But then if you want to separate the finely chopped vegetables from the meat you will have to put much more effort and what you will get will not be as good as at it was at the beginning (unsoldering small components from the PCB). Here is a diagram of the material flow stages used in the electronics industry according to the Sustainability Consortium report: “The Electronics Recycling Landscape” from May 2016, so you can get a general idea of the recycling process in the electronics industry.For the material recovery stage, because of the complexity, and the many different materials found on a modern PCB, there is no universal recycling method that can extract back all raw materials. It is more about determining which metals or materials are more valuable to recover at the moment and balance out the total recovering and recycling output. This process is thoroughly explained in Fairphone’s blog post “How recyclable is the Fairphone 2?” To determine the best recycling process for their phone, they tried out 3 different recycling methods and analyzed their results:
- Smelting and metal refining: Feeding the whole device into a high-temperature metallurgical furnace, recovering mainly metals, alloys, inorganic compounds and energy.
- Dismantling: Separating the product modules and putting them through the most suitable metallurgical and plastic recovery processes.
- Shredding and sorting: Removing the battery from the device if present and feeding the rest of the device through a cutting mill. The resulting scrap is then separated into the relevant processing streams (metallurgy, refining and plastic recovery).
They found out that dismantling was the best recycling approach in terms of recovering materials. Also, they found some interesting remarks:
As you can see, there is no simple solution and the recycling method can vary depending on which material is more valuable in terms of money and embodied energy at the moment of recycling.
I cannot stop talking about electronics recycling without mentioning WEEE. The Waste Electrical and Electronic Equipment Directive was put in placed as a mandatory requirement for all EEE producers in Europe. This legislation ensures accountability and responsibility by the producer regarding the recyclability and disposal of their products sold in the market. It is a huge step to oblige producers to design having recyclability in mind form the beginning and to setup repairment and refurbishment infrastructure.
Embed renewable energies for the powering of the device
How about designing a device so that the power required to fully charge it by the electrical network is halved during its entire lifespan? Or that the battery keeps constantly charging so its lifetime is extended?
Some of these ideas have already been implemented in day to day devices, one of the most legacy product that has an embedded solar photovoltaic panel is a calculator:
Embedding renewable energy generation into the devices has an associated cost that would normally make the product considerably expensive. Therefore market research of the target audience needs to be done first to ensure that the customers will pay the extra for this feature. In some other cases like the calculator, it is so low power and so cheap that the design decision of placing it there is enough.
In this article, we have explored different ways and methods to evaluate and increase the sustainability of an electronic product. To summarize, we can divide the sustainability of an electronic product into the following areas:
- Optimized embodied energy and low C02 footprint in its production and distribution
- No hazardous materials for the environment and people
- Conflict-free minerals
- Optimized use of energy while in use
- Design to last
- End of life potential
- Embed renewable energies for the powering of the device
Hopefully with these guidelines, as a designer, you can start making your designs a little bit “greener” and contribute your grain of sand towards the sustainable development of the electronics industry. This is an on-going topic that evolves every year with new methods and companies adopting this practice, so keep watching for updates.
Do you know of any key parameter I missed on the article? You don’t agree with some point? Please share your thoughts in the comments section below.