Product Carbon Footprint (PCF) Assessment of Dell Laptop – Results and Recommendations Scott O'Connell, Markus Stutz Abstract— The product carbon footprint (PCF) of a mainstream Dell laptop, including raw materials consumption, manufacturing, logistics, product use and end-of-life management was assessed in order to determine environmental “hot spots” across the life cycle. Product bill of material (BOM), supply chain logistics, product energy use and end-of-life scenario data were utilized to model the carbon footprint using generic data found in the GaBi database. The total PCF for three target markets and a life time of four years has been determined to be between 300 and 400kg CO2eq, comparable to driving ca. 1200km in an SUV or drinking ca. 240l of orange juice. The distribution between manufacturing and use is nearly equal, suggesting that an increased focus is needed on improvements within the manufacturing supply chain. Index Terms—product carbon footprint (PCF), laptop, manufacturing, motherboard I. INTRODUCTION P RODUCT Carbon Footprint (PCF) is defined as the “life cycle green house gas (GHG) emissions of goods and services”. In other words the PCF assesses the life cycle GHG emissions that are released as part of the processes of creating, modifying, transporting, storing, using, providing, recycling or disposing of goods and services. GHG include CO2, CH4, N2O, CFCs, etc. and are commonly expressed in kg of CO2 equivalents (kg CO2eq). PCF is a subset of Life Cycle Assessment (LCA), with the analysis limited to emissions that have an effect on climate change. Care has also to be taken that PCF assessment, analysis or accounting is not confused with PCF reporting or labeling. There are some emerging legal and market requirements for PCF assessment, however none of these have been finalized to-date. The most significant legal requirements could come from France, where the Grenelle d’Environment legislation could require that from 1. January 2011 consumers must be informed about the PCF of products. There also have been initiatives in California (Bill AB 19) and in the recast of the EuP (Ecodesign for energy using products) to introduce mandatory PCF assessments and labeling. Increasingly Dell customers are asking for PCF information and retailers such as Tesco in the UK, FNAC in France and Scott O’Connell is with Dell Inc., Environmental Affairs, Austin, TX, 78753, USA (512 723 2512, [email protected]). Markus Stutz is with Dell GmbH, EMEA Environmental Affairs, 60549 Frankfurt, Germany ([email protected]). Walmart in the US are considering PCF for products they are selling. There are also developments to include PCF as one criterion in ecolabels such as EPEAT or Blue Angel. Therefore Dell Environmental Affairs initiated a pilot project for a PCF of a mainstream laptop [1]. II. GOAL AND SCOPE A. Goal of the Study The goal of the study was to assess the Product Carbon Footprint (PCF) of a current Dell laptop with the aim to quantify the PCF in kg of CO2-equivalents (kg CO2eq). Another goal was to determine environmental hot spots over the product’s life cycle, with specific focus on material, component, and product manufacturing and use. The study was not intended for competitive product evaluations. As customer inquiries on PCF of Dell products are increasing, the study was also aimed at developing a white paper and website which could be shared with customers. This study was also intended to prepare for potential future regulation on PCF, which is discussed in France under the Grenelle d’Environment law and possible labelling requirements by retailers. B. Scope of the Study A Dell Latitude E6400 was chosen as the functional unit for this study. This model was selected because it is typical highvolume, mainstream business laptop and therefore representative for a range of similar laptop products. It is also Energy Star® 5.0 qualified and EPEAT Gold registered. Fig. 1. Dell Latitude E6400 laptop. The system boundaries include: 1. 2. 3. 4. 5. 6. 7. Material (=components, parts) and product manufacturing in Asia Transport to final assembly Final assembly in Asia and Europe Transport to customers in the USA, Germany, and China respectively Use in the US, Europe, and China for four years Transport to recycling End of life disposal and recycling. III. LIFE CYCLE INVENTORY A. Background Data In order to facilitate the study, generic data from the GaBi database was used to replace actual data acquisition in factories and assembly plants etc. This specifically is the case for electronic components like integrated circuits (ICs), active and passive components, as well as printed wiring boards. Also generic energy mixes both for manufacturing and use were used. Further generic end of life processes were used to determine impacts at end of life. Certain assumptions were also made for each life cycle phase, as noted in the following sections. Different assumptions may have resulted in different results/conclusions. B. Manufacturing Phase The bill of materials (BOM) was used as a starting point for inventory of components and subassemblies (= the parts). Additionally the laptop was disassembled and the part masses were verified against the BOM. Packaging data of the laptop was available from the Environmental Datasheet (EDS, http://www.dell.com/regulatory_compliance_datasheets), that of the external power supply (EPS) from the BOM. The transport of the five heaviest components and subassemblies (battery, chassis, hard drive, display, and motherboard) to the product manufacturing site in China was taken into account. The transport of the other parts was averaged based on those components. To take into account the scenarios for the three regions (US, Europe, China) different Dell final assembly sites (Malaysia, Poland and China) were included. Energy consumption (electric power, fuels, thermal energy) for each of these final assembly plants was also provided. Depending on the scenario, one or more of these sites are used. For the use in the US a 50% split in final assembly between China and Malaysia was assumed. For use in Europe all final assembly was assumed to take place in Poland. For use in China, all final assembly was assumed to take place in China. C. Logistics Transport from product manufacturing locations in China to Dell final assembly and distribution centers and finally to the customer can be varied, depending on laptop customization level and lead time. For this study, the following assumptions were used to take into account the scenarios for three regions: US • 50% air transport from China to Malaysia • • • • • • • • 50% truck transport within China Air transport from Malaysia or China to western or eastern US 90% truck transport to customer (1500km) 10% air transport to customer (1500km) Europe Air transport from China to Poland Truck transport from Poland to customer (1000km) China Truck transport within China (1200km) Truck transport from China to customer (1500km) D. Use Phase For this study it was deemed appropriate to make use of the method for Energy Star’s Typical Energy Consumption (TEC). The TEC is an agreed upon method of comparing the energy performance of computers, which focuses on the typical electricity consumed while in normal operation during a representative period of time. For laptops the TEC is the value for typical annual electricity use, measured in kilowatthours (kWh), using measurements of average operational mode power levels (off, sleep, idle) scaled by an assumed typical usage model (duty cycle). In case of laptops it is assumed that it spends 60% of its time in off mode, 10% in sleep mode and 30% in idle mode. Idle mode is defined as a state in which the operating system and other software have completed loading, a user profile has been created, the machine is not asleep, and activity is limited to those basic applications that the system starts by default. It is inherently assumed that idle mode is a good proxy for the laptop carrying out work, thus being in an active mode. The benefit of choosing the Energy Star TEC is the possibility to enable benchmarking between various products and manufacturers as well as removing ambiguity caused by different usage patterns. Life time of the product was estimated at 4 years, this is consistent with general business customer use models. It was assumed that the external power supply is connected to the electricity supply 24 hours a day, throughout 365 days of the year. The use phase was considered in each of three main regions: US, Europe and China. In each country the respective distribution routes are applied as well as the country/regionspecific grid mixes during the use phase. These are the US grid mix for the US, the EU-25 grid mix for Europe, and the Chinese grid mix for China. E. End of Life Although it is common for laptops to be refurbished/reused at the end of the first customer use, it was assumed in this study that the laptop was sent for recycling at the end of the first customer use (4 years). A baseline scenario for end of life was adopted according to WEEE, which requires recycling of 75% of the product. To enable analysis of scenarios also a recycling rate of 0%, i.e. 100% of the product goes to landfill (worst case), as well as the best case of 100% recycling were taken into account. Transport distance to recycling was set at 500km by truck in each region. IV. LIFE CYCLE IMPACT ASSESSMENT (LCIA) A. Total Life Cycle Fig. 2 shows the total PCF in the three regions as well as the contribution of the different life cycle phases. The total PCF is between 320kg CO2eq when used in Europe and 370kg CO2eq for use in China. The difference between the regions is relatively small, as the impact from manufacturing is independent of the region of use and as the use phase has a relatively low impact overall. The differences between the regions are of course due to the differing emissions from Manufacturing Transport to recycling Transport to customer Recycling 75% Use phase 500,0 400,0 300,0 transport. This is the case for the US and EU scenario, where the laptops are transported by plane to the distribution centers. The high impact of air transport is due to the fact that it is very energy intensive. Transport by truck, which is the case for the China scenario in contrast has a very low impact. This is also true for the final distribution to the customer from the distribution center. End of life (with the assumption of 75% recycling rate) has a contribution of between 4-9%, reducing the total carbon footprint of the laptop by ca. 30kg of CO2eq in each scenario. Transport to recycling has but a minor contribution, less than 0.1% of the total impact. B. Manufacturing As shown in the previous chapter, manufacturing makes up nearly half of the total product carbon footprint in the US scenario. Since the manufacturing represents a significant contribution, it is further broken down in part production, assembly and transport to customer (see Fig. 3). Upstream material extraction and processing, as well as transport to assembly are included in the part production. 200,0 160 100,0 140 0,0 120 -100,0 EU China power generation in the three regions. Fig. 2. Total Product Carbon Footprint [kg CO2e] of the E6400 laptop in the three regions. 100 kg CO2eq US 80 60 40 The contribution from the use phase represents between 65% (for China) and 47% (in Europe) of total impacts. The contribution of the manufacturing phase is thus relatively high with between 42 and 50% (in China and Europe, resp.). This distribution comes a bit as a surprise, as for most other ICT equipment the use phase dominates by far. In this case the relative complexity of the laptop and its relative short life time results in this change. A key conclusion for mobile (and short lived) products is therefore that the manufacturing phase is gaining in importance with respect to PCF. On the other hand it also points to the fact that a lot of effort has already gone into enhancing energy efficiency of mobile products. Transport to customer is relevant where it includes air 20 0 Part production Assembly Transport to customer Fig. 3. Carbon Footprint [kg CO2eq] of the manufacturing phase (part production, assembly) and the transport to customer. Because of the overwhelming importance production, it is shown in further detail in Fig. 4. of part 80 70 60 kg CO2eq 50 40 30 20 10 rT ra ns po rt Tr uc k Tr an sp or t Ai ey bo ar d K at te ry B up pl y ow er S ac ka gi ng P E xt er na lP D r iv e is k D O pt ic al e ai nb oa rd M D riv Di sk D is pl ay Ha rd C ha ss is In te rn al ca bl es 0 Fig. 4. Carbon Footprint [kg CO2eq] of part production. air and truck transport represent transport to assembly. Upstream material manufacturing processes are contained within the impact of each individual part. There are but a handful of parts that make up about 95% of the total impact caused by part production. These are, in order of importance, the motherboard, the display, the chassis and the battery, with the motherboard alone constituting almost 50% of the total production impacts and over 20% of the total product carbon footprint. An interesting observation is that while the overall mass of both motherboard and display is relatively low, their impact is significant. The chassis, the second-heaviest component (18% by mass) does play an important role in shaping the impact, mostly (ca. 90%) coming from the energy intensive magnesium alloys that make up most of its weight, as well as from aluminium (heat sink) and high-energy plastics (internal frame). Relative to its mass, however, the chassis contributes very little to the overall picture. Notably, the largest part by mass (39%), packaging is hardly even visible in the chart due to the fact that most of its mass is made of paper/cardboard, which requires little energy input and the raw material itself – wood – is a carbon-neutral material. It also becomes instantly clear that transport to assembly (air and truck) does not play a significant role. Further analysis shows that in case of the chassis and the battery, the raw materials and their upstream extraction and processing can be accounted for the high impact, in case of the display and motherboard, the part production processes are responsible. In order to better understand the carbon footprint contribution of the motherboard, it is shown to a further level of detail in Figure 5. Fig. 5. Carbon footprint contributions from components of the motherboard Most of the impacts at this level stem from the RAM bars (two pieces) with 16 integrated circuits (ICs) on each, and gold connectors (200 pins). Although by mass very small, the size and number of ICs is very large compared with the rest of the board. The impact of the ICs derives largely from the energy-intensive manufacture processes especially the silicon wafer manufacture for the die. This motherboard is a prime example of how electronic components are often rather process-intensive than material-intensive, i.e. energy use for manufacturing processes may be responsible for the bulk of the impacts. In case of the RAM bars, the gold pins also contribute significantly to the impact, in this case, however, as with other precious metals – the upstream processes of extraction and purification add the most relevant impacts. Second most noteworthy is the contribution of the substrate itself, i.e. the bare printed wiring board, including the assembly process in which the board is populated with electronic components. Substrate manufacturing is again a highly energy-intensive process, and this rather than the upstream processes behind the constituting materials, determines its impact. Third most relevant is the contribution of the standard active components, i.e. ICs, transistors diodes and LEDs on the motherboard. All these components also contain a die, and as such carry the burden of wafer manufacture, as well precious metals such as gold, silver or palladium. Other larger contributions come from the graphics card (with housing) and the CPU which both contain their own substrate and die. The larger contribution of the graphics card is owing to a larger die size. It is important to note that precious metal content in electronics has decreased over time due to cost. C. Use phase While the use phase represents a significant impact when looking at the total product carbon footprint, not much detail can be derived from this assessment. As easily derived, the time spent in idle (as proxy for active use of the laptop) is responsible for over 90% of the impacts. It is also clear that the assumptions taken for the use phase determine the overall results quite significantly. Taking into account an “active” mode or calculating with weekends and holidays spent in off mode changes the overall impact. Based on internal research we however believe that the Energy Star TEC is a very good proxy for a realistic use of a laptop. D. End of Life (EoL) Fig. 6 shows the impacts and credits associated with the end of life treatment of the laptop in the base case, i.e. assuming 75% recycling rate and no further losses of materials during sorting etc. collected material can be recycled and used to replace primary magnesium with the same alloy content as that of the laptop components. Mechanical recycling, however, is often not possible for nonmetals, such as plastics and paper. In this model, such materials are often incinerated yielding energy (thermal and electric), and this amount is credited much the same way as materials: the amount of energy that is yielded will not need to be produced elsewhere, and therefore the burdens associated with power production for the given amount, are avoided. Incineration, however, has the disadvantage of also producing emissions of greenhouse gases, therefore the impacts in this case are even higher than the generated credits. Shredding of the motherboard yields the second highest credits, owing to the large amount of precious metals to be gained from the ICs and other components. The avoided primary production of those precious metals is of great significance. The landfilled portion of the product, i.e. the 25% not recycled, produces some emissions, but these are minor, due to the assumption of a site allowing inert deposition. Transport to recycling (500km) also has but a minor impact although larger than that of landfill. Fig. 7 shows the impact in the different recycling scenarios. Given the full recycling of the product (100%), credits to be gained are substantial, 1.5 times that of the 75% recycling scenario. Compared with the landfill scenario both recycling options are very favourable with respect to credits yielded in the overall product carbon footprint. Fig. 7. Carbon Footprint (kg CO2eq) of the EoL of the laptop in the three recycling scenarios. Fig. 6. Carbon Footprint (GWP) of the EoL of the laptop. Negative values are credits (reduction of the CO2e) and positive values are impacts from the recycling processes. Inlay: credits from recycling the electronics fraction; key: Au – Gold, Pd – Palladium, Cu – Copper, Ag – Silver. Credits should be understood as avoidance of impacts associated with primary production of the material which is sent to recycling. In cases where the recycled (secondary) material can be used directly to replace the primary material, the primary production of the same amount of material can be avoided, and thus all environmental impacts associated with primary production are also avoided. This is why credits are shown as having a negative impact. Magnesium recycling yields the largest credits, given the assumption that all V. STUDY HIGHLIGHTS & KEY ASPECTS The use phase is by a thin margin the largest contributor when looking at use taking place in the US or in China. For the EU scenario manufacturing dominates by an equally thin margin. The manufacture phase is the second largest contributor to the product carbon footprint (given the selected use phase in the US). The major determinant of the manufacture impact is the motherboard, followed in order of relevance by the display, the chassis and the battery. The first two are process intensive components, while the latter two are rather materialintensive ones. In other words manufacturing processes (energy provision and auxiliary materials therein) are largely responsible for the impact of the motherboard and the display, while upstream material supply and energy demand for mining and processing, are much more relevant for the latter two. Notably, the energy and environmental impacts associated with a unit of mass change dramatically between parts of the laptop. The motherboard production is associated with over 6 times as high carbon footprint per unit of mass as the chassis. While this value is relatively constant for material types, the motherboard’s impact is hardly ever definable by mass due to the complex production processes that are often area-based (substrate size, die size) rather than mass-based. In this specific motherboard the largest impact derives from the RAM bars, the substrate (printed circuit board) itself and the standard active components (ICs, diodes, transistors) in order of importance. Although by size rather small, the RAM bars have 16 ICs each (32 in total) as well as gold connectors (200 pins) along their longer edge, in addition to the substrate which itself is also very energy intensive. Transport to customer should also be mentioned as point of interest, whenever overseas/trans-continental transport is the case. Air transportation, due to the vast amount of kerosene burnt over the long distances, represents the most significant impact in the transport phase of the product life cycle. The recycling gains/credits are substantial. The largely metallic chassis in this laptop can be recycled mechanically, providing credits in the value of the primary raw material (magnesium, aluminium etc.) which amounts to about 50% of the total credits gained from recycling. However, these results are based on a strong underlying assumption that the magnesium alloy employed for most of the chassis is in fact recycled. Magnesium recycling today takes place at relatively low levels since the abundance of this metal does not create sufficient demand on the market for secondary magnesium. Second largest credit is yielded by the recycling of precious metals (especially gold), which by mass may seem like insignificant fractions of the total mass, but by value (economic and environmental) can significantly change the overall impacts. Recycling scenarios with higher or lower collection rates can change the carbon footprint significantly, as was shown. In the 100% recycling scenario ca. 40kg CO2eq reduction is achieved. The 100% landfill scenario on the other hand increases the impact the total product carbon footprint. VI. CONCLUSION The total PCF of the E6400 laptop is comparable to driving 1200km with a Porsche Cayenne (assuming a CO2 emission of 296g/km [2]) or drinking 240l of orange juice (assuming 360g CO2eq/250 ml [3]). This comparison demonstrates that the life cycle impacts over a four year life span of the laptop is relatively modest. Mapping the key impacts to ongoing activities to lower Dell’s product impact show that significant achievements have been made. This is in any case true for lowering product energy consumption in the use phase through efficiency programs such as Energy Star® or Energy Smart. Also the Dell “plant a tree for me” program, enables our customers to voluntarily offset carbon emissions associated with the use phase of the product. Dell’s robust recycling programs, which offers free recycling for consumers, is also enabling to take into account the credit associated with recycling. No such credit can be taken into account if the recycling program is not successful in getting back products to recycling. Actions are also underway within Dell to scope the total GHG scope 1 and 2 emissions from our operations as well as from those of our suppliers (Scope 3). This will help to address the high impacts of manufacturing the parts used in our products, which are also generally used by the overall industry. The impacts from the Dell assembly plants, while very low in comparison, are also offset by maximizing efficiencies, purchasing green power and responsibly offsetting the rest. A key conclusion from this PCF is that for mobile products (with short life times) focus for environmental improvements needs to increasingly shift from use phase to component manufacturing. A set of actions needs to be defined by industry for improving the impacts of component manufacturing. These actions need to focus on the motherboard (RAM, substrate), the display as well as on the chassis and the battery. The role of air transport needs to be further analyzed as well, as it contributes significantly to the overall PCF. Additional PCF of other key ICT products such as desktops, displays, printers, and servers are strongly suggested as follow up research. ACKNOWLEDGMENT The authors thank Dr. Constantin Herrmann, Alexandra Saraev, and Flora Vadas from PE International for their support on this PCF. REFERENCES [1] [2] [3] F. Vadas, A. Saraec, C. Herrmann, “Product Carbon footprint of a Dell Laptop”, 2009 http://www.porsche.com/germany/models/cayenne/cayenne/featuresands pecs/ accessed 08.02.2010 http://www.pcf-world-forum.org/2008/04/tesco-puts-carbon-reductionlabel-on-20-products/ accessed 08.02.2010 THIS WHITE PAPER IS FOR INFORMATIONAL PURPOSES ONLY, AND MAY CONTAIN TYPOGRAPHICAL ERRORS AND TECHNICAL INACCURACIES. THE CONTENT IS PROVIDED AS IS, WITHOUT EXPRESS OR IMPLIED WARRANTIES OF ANY KIND.
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