Adaptable middle-skilled labor: a neglected roadblock to photonics industry growth.

A roadblock to long-term growth of the photonics industry is the availability of well-trained, adaptable middle-skilled workers. This research characterizes the middle-skilled workforce gap, including the quantity required and skills needed. We estimate that 42,000 new technical middle-skilled workers are needed by 2030, requiring another 100 technician programs nationwide. Training skills along the supply chain are critical; programs must emphasize testing, troubleshooting, and process design. Middle-skilled workers trained in critical thinking will enable an adaptable workforce capable of handling technology evolution. Finally, recommendations for the academia, industry, and middle-skilled training ecosystem are included to ensure that the latter evolves with technology development.

Suitability of EPDs for Supporting Life Cycle and Comparative Analysis of Concrete Mixtures.

The use of environmental product declarations (EPDs) of concrete and other construction materials is gaining momentum. EPDs should enable an informed selection of products with a lower environmental footprint; hence, the issue of EPD comparability is highly relevant. In this paper, we identified and discussed the present shortcomings and future opportunities that can promote a meaningful EPD comparison for concrete products. Based on the published EPDs, we suggest a more comprehensive water consumption accounting, as the batching water is commonly underestimated. A set of performance metrics required to be specified for concrete are proposed to be included in the product category rules. An effort to develop a procedure for the regular calibration of existing tools with identical calculation databases and methods can produce outcomes that differ by 1-19%. The incorporation of prescriptive and consistently implemented life cycle inventory can minimize the calculation noise. The incorporation of uncertainty and variability as well as a supply-chain-specific EPD creation can help move toward a robust comparison based on the existing data in EPDs.

The role of concrete in life cycle greenhouse gas emissions of US buildings and pavements.

Concrete is a critical component of deep decarbonization efforts because of both the scale of the industry and because of how its use impacts the building, transportation, and industrial sectors. We use a bottom-up model of current and future building and pavement stocks and construction in the United States to contextualize the role of concrete in greenhouse gas (GHG) reductions strategies under projected and ambitious scenarios, including embodied and use phases of the structures' life cycle. We show that projected improvements in the building sector result in a reduction of 49% of GHG emissions in 2050 relative to 2016 levels, whereas ambitious improvements result in a 57% reduction in 2050, which is 22.5 Gt cumulative saving. The pavements sector shows a larger difference between the two scenarios with a 14% reduction of GHG emissions for projected improvements and a 65% reduction under the ambitious scenario, which is ∼1.35 Gt. This reduction occurs despite the fact that concrete usage in 2050 in the ambitious scenario is over three times that of the projected scenario because of the ways in which concrete lowers use phase emissions. Over 70% of future emissions from new construction are from the use phase.

Urban-Scale Evaluation of Cool Pavement Impacts on the Urban Heat Island Effect and Climate Change.

We implemented a context-sensitive and prospective framework to assess the global warming potential (GWP) impacts of cool pavement strategies on specific roads for different cities. The approach incorporates several interconnections among different elements of the built environment, such as buildings and urban road segments, as well as the transportation fleet, using specific building and pavement information from an urban area. We show that increasing pavement albedo lowers urban air temperatures but can adversely affect the building energy demand in the areas with high incident radiation exposure. The heating energy savings and the radiative forcing effect improve the GWP savings in cold and humid climate conditions. The total GWP savings intensity is sensitive to the city morphology and road traffic. The probabilistic results show that cool pavement strategies can offset 1.0-3.0% and 0.7-6.0% of the total GHG emissions of the U.S. cities Boston and Phoenix, respectively, for a 50-year analysis period. The worldwide range of savings can be as large as 5.0-44.7 Gt of CO2 eq. A paradigm shift in pavement strategy selection is required in most neighborhoods.

Characterizing the Changes in Material Use due to Vehicle Electrification.

Modern automobiles are composed of more than 2000 different compounds comprising 76 different elements. Identifying supply risks across this palette of materials is important to ensure a smooth transition to more sustainable transportation technologies. This paper provides insight into how electrification is changing vehicle composition and how that change drives supply risk vulnerability by providing the first comprehensive, high-resolution (elemental and compound level) snapshot of material use in both conventional and hybrid electric vehicles (HEVs) using a consistent methodology. To make these contributions, we analyze part-level data of material use for seven current year models, ranging from internal combustion engine vehicles (ICEV) to plug-in hybrid vehicles (PHEVs). With this data set, we apply a novel machine learning algorithm to estimate missing or unreported composition data. We propose and apply a metric of vulnerability, referred to as exposure, which captures economic importance and susceptibility to price changes. We find that exposure increases from $874 per vehicle for ICEV passenger vehicles to $2344 per vehicle for SUV PHEVs. The shift to a PHEV fleet would double automaker exposure adding approximately $1 billion per year of supply risk to a hypothetical fleet of a million vehicles. The increase in exposure is largely not only due to the increased use of battery elements like cobalt, graphite, and nickel but also some more commonly used materials, most notably copper.

Perspectives on Cobalt Supply through 2030 in the Face of Changing Demand.

Lithium-ion battery demand, particularly for electric vehicles, is projected to increase by over 300% throughout the next decade. With these expected increases in demand, cobalt (Co)-dependent technologies face the risk of significant impact from supply concentration and mining limitations in the short term. Increased extraction and secondary recovery form the basis of modeling scenarios that examine implications on Co supply to 2030. Demand for Co is estimated to range from 235 to 430 ktonnes in 2030. This upper bound on Co demand in 2030 corresponds to 280% of world refinery capacity in 2016. Supply from scheduled and unscheduled production as well as secondary production is estimated to range from 320 to 460 ktonnes. Our analysis suggests the following: (1) Co price will remain relatively stable in the short term, given that this range suggests even a supply surplus, (2) future Co supply will become more diversified geographically and mined more as a byproduct of nickel (Ni) over this period, and (3) for this demand to be met, attention should be paid to sustained investments in refined supply of Co and secondary recovery.

Quantifying Location-Specific Impacts of Pavement Albedo on Radiative Forcing Using an Analytical Approach.

High-albedo materials reflect more solar radiation and, thereby, alter the earth's radiative balance. Increasing pavement albedo, therefore, has been considered as a technological strategy to mitigate global warming. Previous studies have evaluated this strategy using global average models. To factor this effect into life cycle assessments, location-specific models of the albedo effect for pavements are required. A parametric analytical model is developed to estimate the radiative forcing (RF) using a novel model form and an iterative solution approach. The new model is extended to estimate the corresponding global warming potential (GWP) over an analysis period of 50 years for an albedo change in a pavement surface. This was applied to quantify the GWP impacts of increasing pavement albedo in 14 cities across various climate zones in the US. For the United States, the GWP in kg CO2 equivalent per square meter of altered surface ranges from 0.8 to 1.6 per 0.01 change in albedo, a range of more than 40%. Analysis of a hypothetical albedo change to all darker pavements in the US would produce a negative RF of a magnitude equivalent to that associated with a reduction in CO2 emissions of more than 17 Mton per year.

Regional Heterogeneity in the Emissions Benefits of Electrified and Lightweighted Light-Duty Vehicles.

Electrification and lightweighting technologies are important components of greenhouse gas (GHG) emission reduction strategies for light-duty vehicles. Assessments of GHG emissions from light-duty vehicles should take a cradle-to-grave life cycle perspective and capture important regional effects. We report the first regionally explicit (county-level) life cycle assessment of the use of lightweighting and electrification for light-duty vehicles in the U.S. Regional differences in climate, electric grid burdens, and driving patterns compound to produce significant regional heterogeneity in the GHG benefits of electrification. We show that lightweighting further accentuates these regional differences. In fact, for the midsized cars considered in our analysis, model results suggest that aluminum lightweight vehicles with a combustion engine would have similar emissions to hybrid electric vehicles (HEVs) in about 25% of the counties in the US and lower than battery electric vehicles (BEVs) in 20% of counties. The results highlight the need for a portfolio of fuel efficient offerings to recognize the heterogeneity of regional climate, electric grid burdens, and driving patterns.

Strategic Materials in the Automobile: A Comprehensive Assessment of Strategic and Minor Metals Use in Passenger Cars and Light Trucks.

A comprehensive component-level assessment of several strategic and minor metals (SaMMs), including copper, manganese, magnesium, nickel, tin, niobium, light rare earth elements (LREEs; lanthanum, cerium, praseodymium, neodymium, promethium, and samarium), cobalt, silver, tungsten, heavy rare earth elements (yttrium, europium, gadolinium, terbium, dysprosium, holmium, erbium, thulium, ytterbium, and lutetium), and gold, use in the 2013 model year Ford Fiesta, Focus, Fusion, and F-150 is presented. Representative material contents in cars and light-duty trucks are estimated using comprehensive, component-level data reported by suppliers. Statistical methods are used to accommodate possible errors within the database and provide estimate bounds. Results indicate that there is a high degree of variability in SaMM use and that SaMMs are concentrated in electrical, drivetrain, and suspension subsystems. Results suggest that trucks contain greater amounts of aluminum, nickel, niobium, and silver and significantly greater amounts of magnesium, manganese, gold, and LREEs. We find tin and tungsten use in automobiles to be 3-5 times higher than reported by previous studies which have focused on automotive electronics. Automotive use of strategic and minor metals is substantial, with 2013 vehicle production in the United States, Canada, EU15, and Japan alone accounting for approximately 20% of global production of Mg and Ta and approximately 5% of Al, Cu, and Sn. The data and analysis provide researchers, recyclers, and decision-makers additional insight into the vehicle content of strategic and minor metals of current interest.

Assessing Economic Modulation of Future Critical Materials Use: The Case of Automotive-Related Platinum Group Metals.

Platinum-group metals (PGMs) are technological and economic enablers of many industrial processes. This important role, coupled with their limited geographic availability, has led to PGMs being labeled as "critical materials". Studies of future PGM flows have focused on trends within material flows or macroeconomic indicators. We complement the previous work by introducing a novel technoeconomic model of substitution among PGMs within the automotive sector (the largest user of PGMs) reflecting the rational response of firms to changing prices. The results from the model support previous conclusions that PGM use is likely to grow, in some cases strongly, by 2030 (approximately 45% for Pd and 5% for Pt), driven by the increasing sales of automobiles. The model also indicates that PGM-demand growth will be significantly influenced by the future Pt-to-Pd price ratio, with swings of Pt and Pd demand of as much as 25% if the future price ratio shifts higher or lower even if it stays within the historic range. Fortunately, automotive catalysts are one of the more effectively recycled metals. As such, with proper policy support, recycling can serve to meet some of this growing demand.

Quantifying Domestic Used Electronics Flows using a Combination of Material Flow Methodologies: A US Case Study.

This paper describes the scope, methods, data, and results of a comprehensive quantitative analysis of generation, stock, and collection of used computers and monitors in the United States , specifically desktops, laptops, CRT monitors, and flat panel monitors in the decade leading up to 2010. Generation refers to used electronics coming directly out of use or postuse storage destined for disposal or collection, which encompasses a variety of organizations gathering used electronics for recycling or reuse. Given the lack of actual statistics on flows of used electronics, two separate approaches, the sales obsolescence method (SOM) and the survey scale-up method (SSUM), were used in order to compare the results attained and provide a range for estimated quantities. This study intentionally sought to capture the uncertainty in the estimates. To do so, uncertainty in each data set was incorporated at each stage using Monte Carlo simulations for SOM and establishing scenarios for SSUM. Considering the average results across both methods, we estimate that in 2010 the U.S. generated 130-164 thousand metric tons of used computers and 128-153 thousand tons of used monitors, of which 110-116 thousand tons of used computers and 105-106 thousand tons of used monitors were collected for further reuse, recycling, or export. While each approach has its strengths and weaknesses, both the SOM and the SSUM appear to be capable of producing reasonable ranges of estimates for the generation and collection of used electronics.

A Methodology for Robust Comparative Life Cycle Assessments Incorporating Uncertainty.

We propose a methodology for conducting robust comparative life cycle assessments (LCA) by leveraging uncertainty. The method evaluates a broad range of the possible scenario space in a probabilistic fashion while simultaneously considering uncertainty in input data. The method is intended to ascertain which scenarios have a definitive environmentally preferable choice among the alternatives being compared and the significance of the differences given uncertainty in the parameters, which parameters have the most influence on this difference, and how we can identify the resolvable scenarios (where one alternative in the comparison has a clearly lower environmental impact). This is accomplished via an aggregated probabilistic scenario-aware analysis, followed by an assessment of which scenarios have resolvable alternatives. Decision-tree partitioning algorithms are used to isolate meaningful scenario groups. In instances where the alternatives cannot be resolved for scenarios of interest, influential parameters are identified using sensitivity analysis. If those parameters can be refined, the process can be iterated using the refined parameters. We also present definitions of uncertainty quantities that have not been applied in the field of LCA and approaches for characterizing uncertainty in those quantities. We then demonstrate the methodology through a case study of pavements.

Conflict minerals in the compute sector: estimating extent of tin, tantalum, tungsten, and gold use in ICT products.

Recent legislation has focused attention on the supply chains of tin, tungsten, tantalum, and gold (3TG), specifically those originating from the eastern part of the Democratic Republic of Congo. The unique properties of these so-called "conflict minerals" lead to their use in many products, ranging from medical devices to industrial cutting tools. This paper calculates per product use of 3TG in several information, communication, and technology (ICT) products such as desktops, servers, laptops, smart phones, and tablets. By scaling up individual product estimates to global shipment figures, this work estimates the influence of the ICT sector on 3TG mining in covered countries. The model estimates the upper bound of tin, tungsten, tantalum, and gold use within ICT products to be 2%, 0.1%, 15%, and 3% of the 2013 market share, respectively. This result is projected into the future (2018) based on the anticipated increase in ICT device production.

Impact of policy on greenhouse gas emissions and economics of biodiesel production.

As an alternative transportation fuel to petrodiesel, biodiesel has been promoted within national energy portfolio targets across the world. Early estimations of low lifecycle greenhouse gas (GHG) emissions of biodiesel were a driver behind extensive government support in the form of financial incentives for the industry. However, studies consistently report a high degree of uncertainty in these emissions estimates, raising questions concerning the carbon benefits of biodiesel. Furthermore, the implications of feedstock blending on GHG emissions uncertainty have not been explicitly addressed despite broad practice by the industry to meet fuel quality standards and to control costs. This work investigated the impact of feedstock blending on the characteristics of biodiesel by using a chance-constrained (CC) blend optimization method. The objective of the optimization is minimization of feedstock costs subject to fuel standards and emissions constraints. Results indicate that blending can be used to manage GHG emissions uncertainty characteristics of biodiesel, and to achieve cost reductions through feedstock diversification. Simulations suggest that emissions control policies that restrict the use of certain feedstocks based on their GHG estimates overlook blending practices and benefits, increasing the cost of biodiesel. In contrast, emissions control policies which recognize the multifeedstock nature of biodiesel provide producers with feedstock selection flexibility, enabling them to manage their blend portfolios cost effectively, potentially without compromising fuel quality or emissions reductions.

Quantifying export flows of used electronics: advanced methods to resolve used goods within trade data.

There is limited convincing quantitative data on the export of used electronics from the United States (U.S.). Thus, we advance a methodology to quantify the export flows of whole units of used electronics from the U.S. using detailed export trade data, and demonstrate the methodology using laptops. Since used electronics are not explicitly identified in export trade data, we hypothesize that exports with a low unit value below a used-new threshold specific to a destination world region are used. The importance of using the most disaggregated trade data set available when resolving used and new goods is illustrated. Two detailed U.S. export trade data sets were combined to arrive at quantities and unit values for each port, mode of transport, month, trade partner country, and trade code. We add rigor to the determination of the used-new threshold by utilizing both the Neighborhood valley-emphasis method (NVEM) and published sales prices. This analysis found that 748 to 1199 thousand units of used laptops were exported from the U.S. in 2010, of which 78-81% are destined for non-OECD countries. Asia was found to be the largest destination of used laptop exports across all used-new threshold methods. Latin American and the Caribbean was the second largest recipient of these exports. North America and Europe also received used laptops from the U.S. Only a small fraction of used laptops was exported to Africa. However, these quantities are lower bound estimates because not all shipments of used laptops may be shipped using the proper laptop trade code. Still, this approach has the potential to give insight into the quantity and destinations of the exports if applied to all used electronics product types across a series of years.

Exploring the viability of probabilistic under-specification to streamline life cycle assessment.

Life cycle assessment (LCA) is a technique used to assess the environmental impact of products, processes, or materials. Recently, its importance as a decision-making tool to help evaluate current inventories and innovation of environmentally responsible products has grown; however, the amount of information needed to completely assess even the simplest product's environmental impact may require significant time and resources. Myriad quantitative and qualitative effort-reducing strategies have been considered to accelerate the pace and reduce the cost of LCA. Although these streamlining methodologies reduce the time and effort of conducting LCA, they introduce variability and uncertainty into the results, creating a challenge for stakeholders who may need to make decisions based on the information. This Article explores the impact of streamlining on the credibility of LCA results given the uncertainty in the context of several case studies related to materials production in common consumer products. A technique for the structured analysis of the bill of materials is proposed, which leverages statistical analysis in the context of uncertainty.

Platinum availability for future automotive technologies.

Platinum is an excellent catalyst, can be used at high temperatures, and is stable in many aggressive chemical environments. Consequently, platinum is used in many current industrial applications, notably automotive catalytic converters, and prospective vehicle fuel cells are expected to rely upon it. Between 2005 and 2010, the automotive industry used approximately 40% of mined platinum. Future automotive industry growth and automotive sales shifts toward new technologies could significantly alter platinum demand. The potential risks for decreased platinum availability are evaluated, using an analysis of platinum market characteristics that describes platinum's geophysical constraints, institutional efficiency, and dynamic responsiveness. Results show that platinum demand for an automotive fleet that meets 450 ppm greenhouse gas stabilization goals would require within 10% of historical growth rates of platinum supply before 2025. However, such a fleet, due largely to sales growth in fuel cell vehicles, will more strongly constrain platinum supply in the 2050 time period. While current platinum reserves are sufficient to satisfy this increased demand, decreasing platinum ore grade and continued concentration of platinum supply in a single geographic area are availability risk factors to platinum end-users.

Evaluating rare earth element availability: a case with revolutionary demand from clean technologies.

The future availability of rare earth elements (REEs) is of concern due to monopolistic supply conditions, environmentally unsustainable mining practices, and rapid demand growth. We present an evaluation of potential future demand scenarios for REEs with a focus on the issue of comining. Many assumptions were made to simplify the analysis, but the scenarios identify some key variables that could affect future rare earth markets and market behavior. Increased use of wind energy and electric vehicles are key elements of a more sustainable future. However, since present technologies for electric vehicles and wind turbines rely heavily on dysprosium (Dy) and neodymium (Nd), in rare-earth magnets, future adoption of these technologies may result in large and disproportionate increases in the demand for these two elements. For this study, upper and lower bound usage projections for REE in these applications were developed to evaluate the state of future REE supply availability. In the absence of efficient reuse and recycling or the development of technologies which use lower amounts of Dy and Nd, following a path consistent with stabilization of atmospheric CO(2) at 450 ppm may lead to an increase of more than 700% and 2600% for Nd and Dy, respectively, over the next 25 years if the present REE needs in automotive and wind applications are representative of future needs.

Evaluating the potential for secondary mass savings in vehicle lightweighting.

Secondary mass savings are mass reductions that may be achieved in supporting (load-bearing) vehicle parts when the gross vehicle mass (GVM) is reduced. Mass decompounding is the process by which it is possible to identify further reductions when secondary mass savings result in further reduction of GVM. Maximizing secondary mass savings (SMS) is a key tool for maximizing vehicle fuel economy. In today's industry, the most complex parts, which require significant design detail (and cost), are designed first and frozen while the rest of the development process progresses. This paper presents a tool for estimating SMS potential early in the design process and shows how use of the tool to set SMS targets early, before subsystems become locked in, maximizes mass savings. The potential for SMS in current passenger vehicles is estimated with an empirical model using engineering analysis of vehicle components to determine mass-dependency. Identified mass-dependent components are grouped into subsystems, and linear regression is performed on subsystem mass as a function of GVM. A Monte Carlo simulation is performed to determine the mean and 5th and 95th percentiles for the SMS potential per kilogram of primary mass saved. The model projects that the mean theoretical secondary mass savings potential is 0.95 kg for every 1 kg of primary mass saved, with the 5th percentile at 0.77 kg/kg when all components are available for redesign. The model was used to explore an alternative scenario where realistic manufacturing and design limitations were implemented. In this case study, four key subsystems (of 13 total) were locked-in and this reduced the SMS potential to a mean of 0.12 kg/kg with a 5th percentile of 0.1 kg/kg. Clearly, to maximize the impact of mass reduction, targets need to be established before subsystems become locked in.