Life Cycle Global Warming Potential Research Articles

Life cycle assessment of bioproducts from bamboo residues with biphasic phenoxyethanol-acid based biorefinery technology

Utilizing bamboo residues to produce decarbonization energy products or materials diverts wastes from low-value treatment and supports the circular bioeconomy at the same time. This study develops a cradle-to-grave life-cycle assessment (LCA) for a biorefinery converting bamboo residues into bioproducts (ethanol, polylactic acid (PLA), and bio-based wood adhesive) in China. To combat the low enzymatic hydrolysis performance of bamboo residues and valorize the lignin, this study adopts a biphasic pretreatment by coupling phenoxyethanol and sulfuric acid solution (1%) to achieve high fermentable sugar production. The LCA study is coupled with a process simulation for an industrial-scale biorefinery based on the experimental data. Our results show that the life-cycle Global Warming Potential (GWP) is 17.0–32.1 gCO2e/MJ for ethanol cases and 3.2–3.7 kgCO2e/kg for PLA cases, when biphasic pretreatment is adopted. The lower GWP values are achieved by using 1:1 phenoxyethanol: acid solution, though it has a lower product yield than 4:1 phenoxyethanol: acid solution cases. Without biphasic pretreatment, the GWP is 135.8 gCO2e/MJ ethanol and 4.4 kgCO2e/kg PLA. For the perspective of treating 1 dry t bamboo residues, with biphasic pretreatment, the GWP is −174 to −66 kgCO2e for ethanol cases and −542 to −432 kgCO2e for PLA cases. The lower GWP is also from using 1:1 phenoxyethanol: acid solution (1%). These GWP ranges are lower than conventional landfilling (2969 kgCO2e) and landfilling with landfill gas recovery (−28 kgCO2e).

Geospatially explicit technoeconomic assessment of sustainable aviation fuel production: A regional case study in Virginia

There is strong interest in sustainable aviation fuels (SAF) to decarbonize aviation; however, local decision-makers will need to consider what additional incentives could stimulate SAF commercialization within their own jurisdictions. This study analyzed SAF production in Virginia, evaluating two biomass-to-energy platforms (gasification Fischer Tropsch [GFT] and pyrolysis) and two regionally abundant feedstocks (woody wastes and municipal solid wastes). A suite of open-access modeling tools were applied to possible SAF supply chains encompassing feedstock collection and transportation, conversion, and fuel upgrading and transport. Key modeling outputs were minimum product selling price (MPSP) ($/gallon) and life-cycle global warming potential (GWP) (g CO2eq/MJ). Results suggest that early SAF production via GFT will require local incentives of approximately $3.61 per gallon compared to $0.75 per gallon for pilot-scale pyrolysis. Location of production facility (by county) influences economic and environmental metrics but is not nearly as important as facility size (tonnes/year). Different formats of financial incentives (i.e., tax credits, loan forgiveness, etc.) offer markedly different reductions in SAF MPSP. Finally, under current federal incentives in the US, it is still more economically efficient to use pyrolysis (with higher GWP) than GFT (with lower GWP). Therefore, regional stakeholders will need to navigate the tradeoff between economic and environmental performances of these platforms. Though Virginia was used as a case study, the methodology is replicable for other jurisdictions, insofar it can be adapted for use in other locations without decision-makers having to completely build their own TEA models.

A Building Information Modeling-Based Life Cycle Assessment of the Embodied Carbon and Environmental Impacts of High-Rise Building Structures: A Case Study

High-rise buildings represent technological, urban, and life-style trends of the modern urban landscape, yet there are limited data regarding their embodied carbon and environmental impacts, particularly when compared to low- or mid-rise buildings. Given that the projected growth of the global urban population by 2050 requires cities with higher density and potentially a greater number of high-rise buildings, it is crucial to develop a clear understanding of the embodied carbon and environmental impacts of high-rise buildings. The primary structural materials used in high-rise buildings are reinforced concrete and structural steel. As of today, over 99% of tall buildings’ structures are built from those two materials. This article utilizes a building information modeling (BIM)-based life cycle assessment (LCA) in Revit and Tally to examine the embodied carbon and environmental impacts of an actual high-rise building structure case study in Chicago that uses a hybrid concrete steel structure. The results show that the embodied carbon and environmental impacts of the high-rise building structure are dominated by the impacts of the product stage in the building’s life cycle and by concrete being the main structural material. Specifically, this study reveals that concrete constitutes a substantial 91% share of the total mass of the building structure, with a 74% contribution to the life cycle global warming potential, 53% to the acidification potential, 74% to the eutrophication potential, 74% to the smog formation potential, and 68% to the non-renewable energy usage. On the other hand, steel accounts for 9% of the building’s structure mass, estimated to constitute 26% of the global warming potential, 47% of the acidification potential, 26% of the eutrophication potential, 26% of the smog formation potential, and 32% of the non-renewable energy usage.

The Embodied Life Cycle Global Warming Potential of Off-Site Prefabricated Concrete Products: Precast Concrete and Concrete Pile Production in Korea

The impacts of concrete on global warming through its use in structures such as buildings and infrastructure must be identified and better understood, as concrete is known to have a very high global warming potential (GWP). However, in contrast with ordinary on-site constructed reinforced concrete, GWPs of off-site factory-made prefabricated concrete products such as precast concrete (PC) and concrete piles that are widely used in construction are rarely evaluated, owing to the complicated manufacturing processes that make the determination of greenhouse gas emission difficult. In this study, the embodied life cycle GWPs were derived for PC and pretensioned spun high-strength concrete (PHC) piles to enable precise assessment of the global warming impact of concrete structures and the concrete industry of Korea. The determined embodied GWPs of PC and PHC piles were 1.77 × 10−1 kg CO2 eq/kg and 1.87 × 10−1 kg CO2 eq/kg, respectively. As a result, both prefabricated concrete products were determined to have high GWP due to input materials, such as cement rebars, while the GWP contributions of the off-site prefabrication processes were low. Moreover, the embodied GWPs of both prefabricated concrete products were significantly higher than those of ordinary reinforced concrete, and the impact of both products on global warming was found to be approximately 4% of the impact of the Korean concrete industry. This indicates that it is necessary to consider the impacts of the PHC pile and PC industries when assessing the impacts of greenhouse gas occurring in the concrete industry at the national level. It is expected that these findings will be widely used to obtain a more accurate assessment of the impact of concrete structures and industry on global warming.

The global warming potential and the material utility of PET and bio-based PEF bottles over multiple recycling trips

Biomass use and recycling are among the few options to reduce the greenhouse gas (GHG) emissions of the growing plastics sector. The bio-based plastic polyethylene furanoate (PEF) is a promising alternative to polyethylene terephthalate (PET), in particular for small bottle applications. For the first time, we assessed the life cycle global warming potential (GWP) for 250 mL PET and PEF bottles over multiple mechanical (MR) and chemical (CR) recycling trips in the Netherlands. We found that bio-based PEF would offer 50–74% lower life cycle GHG emission after one recycling trip compared to PET, depending on the waste management case. Our results also show that deposit-based recycling systems significantly reduce the cumulative cradle-to-grave net GHG emissions for both bottle types, especially when multiple recycling trips are applied. We propose complementary material utility (MU) indicators to reveal synergies and trade-offs between circularity and GWP: While deposit-based CR shows the best performance in terms of MU, it falls behind deposit-based MR when it comes to net GHG emissions due to the energy intensity of CR. Hence, combining mechanical and chemical recycling could contribute to achieving the goals of the circular economy and climate change mitigation alike.

Global warming potential, water footprint, and energy demand of shared autonomous electric vehicles incorporating circular economy practices

With the emergence of research on Shared autonomous electric vehicles (SAEVs) as a futuristic transportation option, it becomes important to explore the environmental implications of these types of vehicles before being implemented on a large scale. This work aims to investigate some of the environmental implications of SAEVs compared to privately owned electric vehicles (EVs) through a set of assessment criteria consisting of their life cycle global warming potential (GWP), water footprint and energy demand. In addition, this work examines how different circular economy (CE) practices and energy mixes influence the SAEV's environmental implications. The analysis conducted shows that SAEVs have higher negative environmental effects than private conventional EVs. However, circularity practices were found to decrease these effects. CE practices reduced the GWP, water footprint, and energy demands of SAEVs by 21.4 %, 18.2 %, and 17.3 % respectively. Results have also shown that utilizing the projected 2050 U.S. energy mix and incorporating CE practices throughout the life cycle of an SAEV will decrease the GWP, water footprint, and energy demand by 46 %, 36.2 %, and 39.3 % respectively. In contrast, by utilizing an energy mix that only consists of the clean energy sources of the 2050 U.S. energy mix in the same proportions but forming 100 % of the mix, the GWP, water footprint and energy demand decrease by 73.2 %, 51.2 %, and 29.1 % respectively. The analysis shows that an SAEV will always have higher GWP, water footprint, and energy demand compared to an EV utilizing the same battery due to deadheading and the increased power consumption caused by the additional automation enabling components.

Assessing Efficiency and Environmental Performance of a Nearly Zero-Energy University Building’s Energy System in Norway

Increasing awareness of climate issues in recent decades has led to new policies on buildings’ energy consumption and energy performance. The European Union (EU) directive 2010/31/EC, i.e., the energy performance of buildings directive (EPBD), is one of the measures initiated to achieve climate and energy goals by reducing energy use and greenhouse gas emissions in the building sector. The EPBD required all new buildings to be nearly zero-energy buildings (nZEBs) by 2021. Nearly zero-energy buildings (nZEBs) are buildings with a very-high-energy performance and nearly zero or low-energy requirements covered to a very significant extent by energy from renewable sources produced on-site or nearby. The utilisation of solar photovoltaic (PV) panels is a common approach for achieving the nZEB standard. The carbon footprint of PV panels is often not discussed as a parameter. This paper aimed to analyse the environmental performance of an existing nearly zero-energy university building in a Norwegian use case scenario. This analysis is performed by assessing annual electricity and heat consumption from both energetic and environmental perspectives. The energy required for the building during the studied period is then used to analyse the environmental and energy performance of the building. When it comes to the environmental assessment, the commercial software SimaPro was used. The proposed revision EPBD and nZEB definition from 2021 suggests that nZEBs should also consider operational greenhouse gas emissions and life-cycle global warming potential from 2027. The life cycle assessment (LCA) of the building’s energy sources looks at the global warming potential (GWP) and greenhouse gas (GHG) emissions, and how they compare to Norwegian grid electricity. The results of the analysis highlights potential challenges to justifying the use of alternative energy sources to fulfil the criteria of nZEBs. When installing solar PV, it is important to consider the energy mix of the country where the solar PVs are produced. To solely consider the energy performance of the building, the installation of solar PV panels in countries with a high share of renewable energy may result in a reduced impact in terms of emission reduction from a life cycle perspective.

Environmental and Economic Impacts of Managing Nutrients in Digestate Derived from Sewage Sludge and High-Strength Organic Waste.

Increasingly stringent limits on nutrient discharges are motivating water resource recovery facilities (WRRFs) to consider the implementation of sidestream nutrient removal or recovery technologies. To further increase biogas production and reduce landfilled waste, WRRFs with excess anaerobic digestion capacity can accept other high-strength organic waste (HSOW) streams. The goal of this study was to characterize and evaluate the life-cycle global warming potential (GWP), eutrophication potential, and economic costs and benefits of sidestream nutrient management and biosolid management strategies following digestion of sewage sludge augmented by HSOW. Five sidestream nutrient management strategies were analyzed using environmental life-cycle assessment (LCA) and life-cycle cost analysis (LCCA) for codigestion of municipal sewage sludge with and without HSOW. As expected, thermal stripping and ammonia stripping were characterized by a much lower eutrophication potential than no sidestream treatment; significantly higher fertilizer prices would be needed for this revenue stream to cover the capital and chemical costs. Composting all biosolids dramatically reduced the GWP relative to the baseline biosolid option but had slightly higher eutrophication potential. These complex environmental and economic tradeoffs require utilities to consider their social, environmental, and economic values in addition to present or upcoming nutrient discharge limits prior to making decisions in sidestream and biosolids management.

Dairy Manure Co-composting with Wood Biochar Plays a Critical Role in Meeting Global Methane Goals.

Livestock are the largest source of anthropogenic methane (CH4) emissions, and in intensive dairy systems, manure management can contribute half of livestock CH4. Recent policies such as California’s short-lived climate pollutant reduction law (SB 1383) and the Global Methane Pledge call for cuts to livestock CH4 by 2030. However, investments in CH4 reduction strategies are primarily aimed at liquid dairy manure, whereas stockpiled solids remain a large source of CH4. Here, we measure the CH4 and net greenhouse gas reduction potential of dairy manure biochar-composting, a novel manure management strategy, through a composting experiment and life-cycle analysis. We found that biochar-composting reduces CH4 by 79%, compared to composting without biochar. In addition to reducing CH4 during composting, we show that the added climate benefit from biochar production and application contributes to a substantially reduced life-cycle global warming potential for biochar-composting: −535 kg CO2e Mg–1 manure compared to −194 kg CO2e Mg–1 for composting and 102 kg CO2e Mg–1 for stockpiling. If biochar-composting replaces manure stockpiling and complements anaerobic digestion, California could meet SB 1383 with 132 less digesters. When scaled up globally, biochar-composting could mitigate 1.59 Tg CH4 yr–1 while doubling the climate change mitigation potential from dairy manure management.

Comparative Life Cycle Evaluation of the Global Warming Potential (GWP) Impacts of Renewable Natural Gas Production Pathways

Renewable natural gas (RNG) sources are being considered in future energy strategy discussions as potential replacements for fossil natural gas (FNG). While today’s supply of RNG resources is insufficient to meet U.S. demands, there is significant interest in its viability to supplement and decarbonize the natural gas supply. However, the studies compare the life cycle global warming potential (GWP) of various RNG production pathways are lacking and focus mostly on a singular pathway. This effort is an attempt to close this gap and provide a comparison between the life cycle GWP of three major RNG pathways and the FNG pathway. The three RNG pathways evaluated are anaerobic digestion (AD), thermal gasification (TG), and power-to-gas (P2G) using various feedstocks. The functional unit is 1 MJ of compressed RNG ready for injection into the natural gas transmission network. The results show that RNG production is not always carbon neutral or negative. Depending on the pathway, the GWP impact of RNG production can range from −229 to 27 g CO2e/MJ compressed RNG, with AD of animal manure and AD of municipal solid waste being the least and the most impactful pathways, respectively, compared to the 10.1 g CO2e/MJ impact for compressed FNG.

Environmental Impact Assessment of Hole Conductor Layer Free and Flexible Organo Lead Iodide Perovskite Solar Cell

Perovskite solar cells (PSCs) have shown a significant increment in power conversion efficiency recently with advantages such as flexibility and low-cost roll-to-roll production. Prior to the commercialization of PSCs, it is significant to investigate its environmental performance with life cycle assessment method. In this work, cradle to gate LCA of solution-based organo-lead iodide perovskite solar cell performed according to the one reported literature method that comprises flexible Polyethylene terephthalate (PET) substrate and hole transport layer (HTL) elimination. Environmental impacts from the generation of 1 m2 of cell area production are determined in six International Reference Life Cycle Data System (ILCD) categories. It is found that the major impact comes from the fabrication of the aluminum metal electrode layer due to the high electrical energy required in the vacuum deposition process. The life cycle global warming potential (GWP) that the most widely used environmental indicator has been calculated for per kWh electricity production to make a comparison with commercial photovoltaic technologies. It is found that the HTL-free flexible (HFF) PSC needs 15-20 years of device lifetime to reach competitive GWP value with commercial PVs.

Sensitivity of buildings’ carbon footprint to electricity decarbonization: a life cycle–based multi-objective optimization approach

PurposeLife cycle assessment (LCA) is a widely used method for the evaluation of buildings’ environmental impacts, but these analyses contain high levels of uncertainty. Decarbonization of electricity production is key to reach climate goals, influencing all sectors including construction The objective of this paper is to study the sensitivity of the environmentally optimum building design solution to a changing electricity mix to assist decision-making.MethodsIn this paper, multi-objective optimization was applied to minimize the life cycle global warming potential and life cycle costs of a building at the same time, using dynamic energy simulation and LCA. The variables include building envelope parameters such as window ratio, insulation type and thickness in a typical new multi-family apartment building heated with a heat pump. A static, largely fossil-based electricity mix and a dynamic, gradually decarbonizing alternative are considered, as well as two electricity price increase scenarios. New metrics have been introduced to explore the results and describe the Pareto-optimal solutions, for example the improvement potential to contextualize the achievements through the optimization.Results and discussionThe results show that, with the current electricity mix, building envelope optimization can improve the design by 18% on average in terms of the life cycle greenhouse gas emissions compared to typical new designs and by 10% with a dynamic mix in Hungary. With today’s static electricity mix, the optimization proved that the minimum energy efficiency requirements in force are close to cost optimality. However, from an environmental point of view, much higher insulation thicknesses have been shown as justified (U-values of less than 0.1 W/m2K).ConclusionsOptimization of building design based on LCA is still not widely applied and the effect of a decarbonizing electricity mix on the optimum has not been studied before. The results of the paper demonstrate the importance of this question. Optimal solutions are different depending on the applied mix but an energy-efficient building envelope remains important: today’s cost-optimal building envelope proves to be both cost- and environmentally optimal in the long run.

Life cycle energy and greenhouse gas emissions implications of polyamide 12 recycling from selective laser sintering for an injection‐molded automotive component

AbstractThe selective laser sintering (SLS) process generates waste polymer powders, which can be recycled as feedstock for producing injection‐molded components. Recycling this powder has implications on the life cycle modeling of the SLS product, as well as the subsequent injection‐molded component. This study investigates the life cycle primary energy demand (PED) and global warming potential (GWP) of an automotive fuel‐line clip produced with recycled polyamide 12 (PA12) from an SLS process in comparison to the conventional polyamide 66 (PA66) counterpart, based on real‐world industry data. In addition, the life cycle PED and GWP of an SLS part are examined, with and without recycling PA12 from the SLS process. The results indicate a strong dependence on the approach to evaluate the environmental burden of waste PA12 from the SLS process (cut‐off, mass‐based allocation, economic allocation, and substitution). Compared with the PA66 fuel‐line clip, the recycled PA12 (rPA12) clip reduces the life cycle GWP by up to 26% (cut‐off) or increases by up to 68% (mass‐based allocation). For the SLS part, recycling PA12 powder provides a 42% reduction to its life cycle GWP (mass‐based allocation). Finally, from an expanded two‐part system perspective, the recycling of PA12 from the SLS process provides an 8% reduction in life cycle GWP. Similar trends are shown for the life cycle PED profiles. This study demonstrates the importance of recycling additive manufacturing (AM) wastes within a broader cascading system to improve the environmental performance of AM and the circular economy across industrial systems.

Environmental and economic performance of carbon capture with sodium hydroxide

Carbon capture and utilization processes can lead to the manufacture of carbonates with low, neutral or even negative carbon footprint. In this sense, we consider the utilization of solid sodium hydroxide, NaOH, as an agent for CO2 capture in different conceptual approaches to produce usable carbonates. The experimental background on this application has proven its technical feasibility, although the high cost and carbon footprint of the electrolytic production of NaOH, mainly due to high electricity consumption, are the main barriers for a widespread adoption. However, the use of NaOH has not yet been compared and benchmarked in the current and future scenarios of carbon capture, where the share of renewable sources is progressively increasing in many national electricity mixes and further applications of carbonates are potentially available. To account for these scenarios, we considered different sources of CO2 and NaOH, and the potential utilization of the generated products. Altogether, we evaluated 18 scenarios regarding the impact on life cycle global warming potential and fossil resources depletion, along with the cost of capture. Results show that net emissions savings and potential cost reductions are attainable for both flue-gas and air-based capture processes, provided that the resulting sodium carbonate is used to substitute the current, Solvay-based, production of sodium carbonate.

A comparative life cycle analysis of electromicrobial production systems

We employ physics-based bioreactor modelling and life cycle assessment to evaluate three potential electromicrobial production systems in terms of their productivity, energy demand, life cycle global warming potential, and land use.

Environmental life cycle assessment of supercapacitor electrode production using algae derived biochar aerogel

Porous carbon aerogel material has gained an increasing attraction for developing supercapacitor electrodes due to its cost-effective synthesis process and relatively high electrochemical performance. However, the environmental performances of supercapacitor electrodes produced from different carbon aerogel materials are never comparatively studied, hindering our knowledge of supercapacitor electrode production in a sustainable pattern. In this study, nitrogen-doped biochar aerogel-based electrode (BA-electrode) produced from Entermorpha prolifera was simulated to investigate the environmental performance by using life cycle assessment method. For comparison, the assessment of graphene oxide aerogel-based electrode (GOA-electrode) was also carried out. It can be observed that the life cycle global warming potential for the BA-electrode was lower than that of GOA-electrode with a reduction of 53.1‒68.1%. In comparison with GOA-electrode, the BA-electrodes endowed smaller impacts on environment in majority of impact categories. Moreover, in comparison with GOA-electrode, the environmental damages of BA-electrode were greatly decreased by 35.8‒56.4% (human health), 44.9‒62.6% (ecosystems), and 87.0‒91.2% (resources), respectively. The production stages of GOA and graphene oxide and stages of nitrogen-doped biochar aerogel production and Entermorpha prolifera drying were identified as the hotspots of environmental impact/damage for the GOA-electrode and BA-electrode, respectively. Overall, this finding highlights the efficient utilization of algae feedstock to construct a green and sustainable technical route of supercapacitor electrode production.

Prospective Environmental Impacts of Passenger Cars under Different Energy and Steel Production Scenarios

The potential environmental impacts of producing and using future electric vehicles (EVs) are important given their expected role in mitigating global climate change and local air pollutants. Recently, studies have begun assessing the effect of potential future changes in EVs supply chains on overall environmental performance. This study contributes by integrating expected changes in future energy, iron, and steel production in the life cycle assessment (LCA) of EVs. In this light, the study examines the impacts of changes in these parameters on producing and charging future EVs. Future battery electric vehicles (BEV) could have a 36–53% lower global warming potential (GWP) compared to current BEV. The change in source of electricity generation accounts for 89% of GWP reductions over the BEV’s life cycle. Thus, it presents the highest GWP reduction potential of 35–48%. The use of hydrogen for direct reduction of iron in steelmaking (HDR-I) is expected to reduce vehicle production GWP by 17% compared to current technology. By accounting for 9% of the life cycle GWP reductions, HDR-I has the second-highest reduction potential (1.3–4.8%). The results also show that the potential for energy efficiency improvement measures for GWP reduction in vehicle and battery manufacture would be more beneficial when applied now than in the distant future (2050), when the CO2 intensity of the EU electricity is expected to be lower. Interestingly, under the same conditions, the high share of renewable energy in vehicle supply chains contributed to a decrease in all air pollution-related impact categories, but an increase in toxicity-related categories, as well as land use and water consumption.

Hybridization of complete PLCA and MRIO databases for a comprehensive product system coverage

AbstractProcess‐based Life Cycle Assessments (PLCA) rely on detailed descriptions of extensive value chains and their associated exchanges with the environment, but major data gaps limit the completeness of these system descriptions and lead to truncations in inventories and underestimations of impacts. Hybrid Life Cycle Assessments (HLCA) aim to combine the strength of PLCA and Environmentally Extended Input Output (EEIO) analysis to obtain more specific and complete system descriptions. Currently, however, most HLCAs only remediate truncation of processes that are specific to each case study (foreground processes), and these processes are then linked to (truncated) generic background processes from a non‐hybridized PLCA database. A hybrid PLCA‐EEIO database is therefore required to completely solve the truncation problems of PLCA and thus obtain a comprehensive product system coverage. This paper describes the construction of such a database using pyLCAIO, a novel framework and open‐source software enabling the streamlined hybridization of entire PLCA and EEIO databases. We applied this framework to the PLCA database Ecoinvent3.5 and the multiregional EEIO database EXIOBASE 3. Thanks to the correction for truncation in this new hybrid database, the median and average life cycle global warming potential (GWP) of its processes increased by 7% and 14%, respectively. These corrections only reflect the truncations that could be readily identified and estimated in a semi‐automated manner; and we anticipate that further database integration should lead to higher levels of correction in the future.

Assessing the Climate Change Mitigation Potential of Stationary Energy Storage for Electricity Grid Services.

This paper presents a life cycle assessment for three stationary energy storage systems (ESS): lithium iron phosphate (LFP) battery, vanadium redox flow battery (VRFB), and liquid air energy storage (LAES). The global warming potential (GWP) is assessed in relation to uncertainties in usage of the storage, use-phase energy input, cell replacement, and round-trip efficiency parameters. Relative climate change mitigation potential in comparison with equivalent diesel electric and natural gas generation is discussed, as is the effect of recycling at end of life. With variations in input electricity source, recycling, and efficiency, the life cycle global warming potential for LFP ranges from 185 to 440 kg CO2 eq/MWh, for VRFB from 121 to 443 kg CO2 eq/MWh, and for LAES from 48 to 203 kg CO2 eq/MWh. In all cases, there are climate change mitigation benefits compared to fossil fuel alternatives. Use of renewable energy for charging and operation, ease of component recycling/reuse, and reduced parts replacement is shown to reduce GWP. The climate change mitigation potential of ESS for electricity grid operation is further enhanced by increasing use of the storage assets. Recycling of ESS is shown to reduce terrestrial acidification, freshwater eutrophication, and particulate matter impacts. Reduced ozone depletion potential for VRFB and LFP can be achieved by reducing nafion and PVDF components, respectively.

How has LCA been applied to 3D printing? A systematic literature review and recommendations for future studies

Abstract Previously perceived as a rapid prototyping technique, additive manufacturing (AM) has evolved into a fully developed manufacturing process, with growing accessibility to different industrial sectors. Its technological and economic advantages are frequently documented, but AM’s environmental performance is seldom investigated. Not long ago discrete initiatives to assess AM’s applicability for building large-scale structures started to arise. Mostly focused on technical and economic feasibility, these studies pave the way for the process’s consolidation in the construction sector. This paper aims to systematically and critically assess the available literature on AM’s life cycle environmental impacts and to identify the main challenges and trends on loads measurements. The findings help feed recommendations to perform life cycle assessments (LCA) in AM initiatives, with a special focus on the construction sector. A systematic search led to the careful analysis of 52 papers, out of 353 that matched our search protocol. In terms of LCA methods’ robustness, a lack of transparency stood out in many papers, suggesting that authors were most likely non-LCA experts, applying the tool without much knowledge of requirements and modelling intricacies. In terms of documented global warming potential (GWP) values in comparison to conventional manufacturing (CM), AM processes were portrayed as beneficial in most cases. Most papers documented results ranges, which represented different printing, production or distribution strategies, in which AM’s performance varied considerably. LCA played a significant role in finding an optimum production approach and seems to be a valuable lens to assure 3D printing’s environmental competitiveness. A contribution analysis showed that there is a shift between materials vs. production processes contribution in the life cycle GWP loads of systems manufactured with AM and CM. 3D printing processes account for almost 80% of AM’s total GWP, while for CM that position is held by the material-related loads. For construction related AM processes, the material intensity is, however, still by far the largest contributor to building systems’ GWP, maintaining the impact distribution as in typical manufacturing processes.