LCA of Multicrystalline Silicon Photovoltaic Systems - Part 2: Application on an Island Economy (8 pp)

- Part 1: Present Situation and Future Perspectives Part 2: Application on an Island Economy Goal, Scope and Background In the first part of this paper, we developed a methodology to incorporate exposure and risk concepts into life cycle impact assessment (LCIA). We argued that both risk assessment and LCIA are needed to consider the impacts of increasing insulation for single-family homes in the US from current practice to the levels recommended by the 2000 International Energy Conservation Codes. In this analysis, we apply our model to the insulation case study and evaluate the benefits and costs of increased insulation for new housing. Results and Discussion The central estimate of impacts from the complete insulation manufacturing supply chain is approximately 17 premature deaths, 470 asthma attacks, and 8.100 restricted activity days nationwide for one year of increased fiberglass output. Of the health impacts associated with increased insulation manufacturing, 83% are attributable to the supply chain emissions from the mineral wool industry, which is mostly associated with the direct primary PM2.5 emissions from the industry (98%). Reduced energy consumption leads to 1.3 premature deaths, 36 asthma attacks, and 610 restricted activity days avoided per year, indicating a public health 'payback period' on the order of 13 years. Almost 90% of these benefits were associated with direct emissions from power plants and residential combustion sources. In total, the net present value of economic benefits over a 50-year period for a single-year cohort of new homes is $240 million with a 5% discount rate, with 49 fewer premature deaths in this period. Conclusion Recommendation and Outlook. We have developed and applied a risk-based model to quantify the public health costs and benefits of increased insulation in new single-family homes in the US, demonstrating positive net economic and public health benefits within the lifetimes of the homes. More broadly, we demonstrated that it is feasible to incorporate exposure and risk concepts into I-O LCA, relying on regression-based intake fractions followed by more refined dispersion modeling. The refinement step is recommended especially if primary PM2.5 is an important source of exposure and if stack heights are relatively low. Where secondary PM2.5 is more important, use of regression-based intake fractions would be sufficient for a reasonable risk approximation. Uncertainties in our risk-based model should be carefully considered; nevertheless, our study can help decision-makers evaluate the costs and benefits of demand-side management policy options from a combined public health and life cycle perspective.     

Device Performance of Emerging Photovoltaic Materials (Version 3)

Following the 2nd release of the “Emerging PV reports,” the best achievements in the performance of emerging photovoltaic devices in diverse emerging photovoltaic research subjects are summarized, as reported in peer-reviewed articles in academic journals since August 2021. Updated graphs, tables, and analyses are provided with several performance parameters, e.g., power conversion efficiency, open-circuit voltage, short-circuit current density, fill factor, light utilization efficiency, and stability test energy yield. These parameters are presented as a function of the photovoltaic bandgap energy and the average visible transmittance for each technology and application, and are put into perspective using, e.g., the detailed balance efficiency limit. The 3rd installment of the “Emerging PV reports” extends the scope toward triple junction solar cells.     

Feasibility of Applying Site-dependent Impact Assessment of Acidification in LCA (8 pp)

Goal, Scope and Background Taking into account the location of emissions and its subsequent, site-dependent impacts improves the accuracy of LCIA. Opponents of site-dependent impact assessment argue that it is too time-consuming to collect the required additional inventory data. In this paper we quantify this time and look into the added value of site-dependent LCIA results. Methods We recalculated the acidifying impact for three existing LCA studies: linoleum, stone wool, and water piping systems. The amount of time needed to collect the required additional data is reported. The EDIP2003 methodology provides site-generic and site-dependent acidification factors. We used these factors to recalculate acidification for the case studies. We analyzed differences between site-generic and site-dependent acidification and reported problems experienced. Results and Discussion Finding the location of processes and emissions was easy. The reports of the three case studies contained most of this information. Far more time was needed to disaggregate processes to the level where emissions can be localized. Although the overall conclusions with regard to acidification did not change in the case studies, the relative importance of processes shifted when considering sub-levels. This is especially important for improvement analysis. Site-dependent acidification assessment was hampered in the linoleum case study where about 40% of the acidification originates from non-European emissions. However, EDIP2003 provides no site-dependent factors for these countries and site-generic factors had to be used instead. Thus, calculating site-dependent acidification is only feasible for LCA studies in which the majority of the emissions originate in Europe. We could not reproduce all parts of the three case studies using the report and additional public resources. This hindered our recalculation. In fact, any additional analysis will be hampered by this lack of reproducibility. ISO recommends such reproducibility for comparative assertion disclosed to the public. Conclusion Spatially differentiated acidification is feasible for each of the three case studies. Finding the location of processes and emissions was easy, but quite some time was needed to disaggregate processes and emissions to the appropriate level. Overall conclusions on acidification remained the same for the case studies, but the relative contribution of basic processes changed when applying site-dependent impact assessment. Though the three case studies were all rather detailed and complete, none of them was fully reproducible. This complicated recalculation of acidification, and will in fact make any additional analysis difficult.     

Economic and Social Impact Assessment of China's Multi‐Crystalline Silicon Photovoltaic Modules Production

It is important to have insights into the potential sustainability impacts as early as possible in the development of technology. Solar photovoltaic (PV) technologies provide significant environmental, economic, and social benefits in comparison to the conventional energy sources. Because most previous studies of multi‐crystalline silicon (Multi‐Si) PV modules discuss the environmental impacts, this study quantitatively assesses the economic and social impacts of China's multi‐crystalline silicon (mc‐Si) PV modules production stages. The economic analysis is uses life cycle cost analysis, and the social impact analysis is carried out by applying the social index evaluation method. The economic analysis results demonstrate that the main cost of mc‐Si PV modules production in China lies in raw materials and labor and the production of Multi‐Si PV cells have the highest cost among the five manufacturing processes involved in Multi‐Si PV. The result of the social impact analysis reveal that the employment contribution index, S₁₁, is 0.72, indicating that Multi‐Si PV modules production in China has a prominent contribution to employment in comparison with other industries; the labor civilization degree, S₁₂ (i.e., the proportion of mental labor involved in a given job), and labor income contribution index, S₁₃, are both approximately 0.6, indicating that Multi‐Si PV modules production has a less‐significant labor level and income contribution in comparison with other industries; the production capacity contribution index, S₁₄, is merely 0.183, indicating that production of Multi‐Si PV modules does not contribute significantly to the gross domestic product (GDP). Based on the results of these evaluations, some recommendations to improve the economic and social impact of Multi‐Si PV modules production in China are presented, including support for research on polycrystalline silicon production for the purpose of reducing the raw material cost, as well as upgrading manufacturing facilities and implementing the corresponding production training in order to promote the labor civilization degree.     

Scenario Modelling in Prospective LCA of Transport Systems. Application of Formative Scenario Analysis (11 pp)

Background Tools and methods able to cope with uncertainties are essential for improving the credibility of Life Cycle Assessment (LCA) as a decision support tool. Previous approaches have focussed predominately upon data quality. Objective and Scope. An epistemological approach is presented conceptualising uncertainties in a comparative, prospective, attributional LCA. This is achieved by considering a set of cornerstone scenarios representing future developments of an entire Life Cycle Inventory (LCI) product system. We illustrate the method using a comparison of future transport systems. Method Scenario modelling is organized by means of Formative Scenario Analysis (FSA), which provides a set of possible and consistent scenarios of those unit processes of an LCI product system which are time dependent and of environmental importance. Scenarios are combinations of levels of socio-economic or technological impact variables. Two core elements of FSA are applied in LCI scenario modelling. So-called impact matrix analysis is applied to determine the relationship between unit process specific socio-economic variables and technology variables. Consistency Analysis is employed to integrate unit process scenarios, based on pair-wise ratings of the consistency of the levels of socio-economic impact variables of all unit processes. Two software applications are employed which are available from the authors. Results and Discussion The study reveals that each possible level or development of a technology variable is best conceived of as the impact of a specific socio-economic (sub-) scenario. This allows for linking possible future technology options within the socio-economic context of the future development of various background processes. In an illustrative case study, the climate change scores and nitrogen dioxide scores per seat kilometre for six technology options of regional rail transport are compared. Similar scores are calculated for a future bus alternative and an average Swiss car. The scenarios are deliberately chosen to maximise diversity. That is, they represent the entire range of future possible developments. Reference data and the unit process structure are taken from the Swiss LCA database 'ecoinvent 2000'. The results reveal that rail transport remains the best option for future regional transport in Switzerland. In all four assessed scenarios, four technology options of future rail transport perform considerably better than regional bus transport and car transport. Conclusions and Recommendations. The case study demonstrates the general feasibility of the developed approach for attributional prospective LCA. It allows for a focussed and in-depth analysis of the future development of each single unit process, while still accounting for the requirements of the final scenario integration. Due to its high transparency, the procedure supports the validation of LCI results. Furthermore, it is well-suited for incorporation into participatory methods so as to increase their credibility. Outlook and Future Work. Thus far, the proposed approach is only applied on a vehicle level not taking into account alterations in demand and use of different transport modes. Future projects will enhance the approach by tackling uncertainties in technology assessment of future transport systems. For instance, environmental interventions involving future maglev technology will be assessed so as to account for induced traffic generated by the introduction of a new transport system.     

The relative mass-energy-economic (RMEE) method for system boundary selection Part 1: A means to systematically and quantitatively select LCA boundaries

Life-cycle assessment (LCA) is being used more and more as a decision making tool to compare alternative systems of providing a given product or service. Each system is theoretically made up of a near infinite number of elements or unit processes to produce the product or service. In practice, time and resources to complete an LCA are limited, hence the need to draw practical boundaries on the systems being analyzed. However, how does the LCA practitioner draw fair boundaries on two or more different systems being compared? In other words, how does one decide which unit processes to include in each system? A consistent quantitative method of selecting boundaries is essential for comparative LCA studies. This paper first outlines the requirements for a system boundary selection methodology and then demonstrates the shortfalls of existing methods. The primary objective is to present the Relative Mass-Energy-Economic (RMEE) method for system boundary selection. This concise, repeatable and quantitative method for selecting system boundaries for LCA is demonstrated on a life-cycle system for ethanol fuel. Unlike many other methods of selecting system boundaries, the RMEE method is practical to use and quantitatively ensures different systems have similar system boundaries to ensure a fair comparison between options. The RMEE method has been designed specifically for LCA studies of energy systems     

A New LCA Methodology of Technology Evolution (TE-LCA) and its Application to the Production of Ammonia (1950-2000) (8 pp)

Goal, Scope and Background

This paper presents a new LCA method of technology evolution (TE-LCA), and its application to the production of ammonia, the second largest chemical product in the world, over the last fifty years. The TE-LCA of a chemical process is the procedure in which historical information on a process, mainly the evolution of technical parameters, is translated by simulation to mass and energy balances as a function of time. These mass and energy balances are then transformed into environmental impact indicators using common LCA approaches. Finally, the evolution of environmental impact resulting from the investigated process can be related to its technical and other, i.e. legislative, developments.

Methods

The technological evolution of the production of ammonia was compiled according to three basic sources of information: patents, publications and industry data. From these sources in a first step, the major technological advances of the process were identified as a function of time delivering different process variants that were modelled using the simulation software Aspen Plus®. In a second step, the evolution of environmental regulations is studied. For those energy related emissions that were regulated, e.g. SOx and NOx, it was assumed that threshold values defined in legislation were realized immediately. The aggregation of both steps allows the calculation of the emissions resulting from the production (cradle to gate view) of the investigated chemical as a function of time.

Results and Discussion

The application of the TE-LCA to the production of ammonia revealed when and to which extent technological and legislative developments resulted in the reduction of energy related emissions in the production of this chemical compound. Overall, the reduction of emissions from ammonia production was highly influenced by the technological development and only to a lower extent by environmental regulations.

Conclusion

The results obtained from the TE-LCA method is useful to reveal how the environmental performance of a process developed in the past and to identify the reasons for this development. The investigated case study of ammonia production shows that investment in technological development also paid off in terms of being ahead of tightened environmental legislation that might bear potential cost consequences such as carbon dioxide tax.

Outlook

The presented method can be easily extended by including an economic analysis, which provides additional information on why certain technological developments were enforced and which the economic consequences of changes in environmental legislation were. The new methodology has to be applied to additional case studies, i.e. to other chemical sectors than basic chemicals and to other branches than chemicals. In other chemical sectors, toxic emissions from the production process might have to be considered and trade-offs between these and the overall energy consumption might result.     

Manufacturing and Disposal of Building Materials and Inventorying Infrastructure in ecoinvent (8 pp)

Goal, Scope and Background The present paper describes the goal and scope of building material inventories in the ecoinvent database and gives an overview of its content. The ecoinvent database provides generic life cycle inventories for building material production and related processing. They can be used as background data for different LCA applications. Their geographical and temporal scope is Switzerland or Europe and the year 2000.Methods Data is inventoried as unit processes. Consistency throughout different sources is heeded by systematically estimating missing data. Infrastructure is consequently considered. Different disposal options are modelled.Results and Conclusion The ecoinvent data provide a harmonised basis for different kinds of building materials. Even though not all datasets could be established on the same quality level, the results generally are believed to be comparable. Since data are generic, they are, however, not suitable to directly compare specific products. Disposal is relevant for the environmental burdens of uses of building materials. Complete life cycles have to be assessed. For this purpose, cumulative energy demand (CED) is not a suitable indicator.Recommendation and Perspective In future versions of ecoinvent, data quality could be further improved. The database should be extended to include further building materials from secondary materials. To do so, the methodological treatment of secondary materials needs special attention.     

Life Cycle Assessment of Water Production Technologies - Part 1: Life Cycle Assessment of Different Commercial Desalination Technologies (MSF,MED, RO) (9 pp)

- Preamble. This series of two papers analyses and compares the environmental loads of different water production technologies in order to establish, in a global, rigorous and objective way, the less aggressive technology for the environment with the present state of the art of the technology. Further, it is also presented an estimation of the potential environmental loads that the considered technologies could provoke in future, taking into account the most suitable evolution of the technology. - Part 1 presents the assessment of most commercial desalination technologies which are spread worldwide: Reverse Osmosis, Multi Effect Desalination and Multi Stage Flash. Part 2 presents the comparative LCA analysis of a big hydraulic infrastructure, as is to be found in the Ebro River Water Transfer project, with respect to desalination. - DOI: http://dx.doi.org/10.1065/lca2004.09.179.1 - Intention, Goal and Background. In this paper, some relevant results of a research work are presented, the main aim of which consists of performing the environmental assessment of different water production technologies in order to establish, in a global, rigorous and objective way, the less aggressive technology for the environment of potable water supply to the end users. That is, the scope of this paper is mostly oriented to the comparative Life Cycle Assessment of different water production technologies instead of presenting new advancements in the LCA methodology. In Part 1, the environmental loads associated with the most widespread and important commercial desalination technologies all over the world - Reverse Osmosis (RO), Multi Effect Desalination (MED) and Multi Stage Flash (MSF) – are compared. The assessment technique is the Life Cycle Analysis (LCA), which includes the entire life cycle of each technology, encompassing: extraction and processing raw materials, manufacturing, transportation and distribution, operation and final waste disposal.- Methods and Main Features. The software SimaPro 5.0, developed by Dutch PRé Consultants, has been used as the analysis tool, because it is a well known, internationally accepted and validated tool. Different evaluation methods have been applied in the LCA evaluation: CML 2 baseline 2000, Eco-Points 97 and Eco-Indicator 99. Data used in the inventory analysis of this Part 1 come from: a) existing plants in operation; b) data bases implemented in the SimaPro 5.0 software -BUWAL 250, ETH-ESU 96, IDEMAT 2001. Different scenarios have been analyzed in both parts in order to estimate, not only the potential of reduction of the provoked environmental loads with the present state of the art of technology, but also the most likely future trend of technological evolution. In Part 1, different energy production models and the integration of desalination with other productive processes are studied, while the effect of the most likely technological evolution in the midterm, and the estimation of the environmental loads to the water transfer during drought periods are considered in Part 2. Results and Discussion The main contribution to the global environmental impact of desalination technologies comes from the operation, while the other phases, construction and disposal, are almost negligible when compared to it. Energy is very important in desalination, for this reason the environmental loads change a lot depending on the technology used for providing the energy used in the desalination process. Among the different analyzed technologies, RO is the least aggressive desalination technology (one order of magnitude lower than the thermal processes, MSF and MED) for the environment. When integrating thermal desalination with other productive processes taking advantage of the residual heat, the environmental loads of thermal desalination technologies is highly reduced, obtaining similar loads to that of RO. The environmental loads of desalination technologies are significantly reduced when an energy model based on renewable energies is used. Taking into account the technological evolution, which is experiencing the RO, a reduction of its environmental load by about 40% is to be expected in the mid-term. Conclusion The main conclusion of Part 1 is that, with the present state of the art of the technology, RO is clearly the desalination technology with a reduced environmental load (one order of magnitude lower than the thermal processes, MSF and MED). In the case of thermal desalination technologies, their environmental load can be highly reduced (about 1,000 times less) when integrated with other industrial processes. In the case of RO, the scores and the airborne emissions obtained from an electricity production model based on renewable energies are about 65-70 times lower than those obtained when the electricity production model is mainly based on fossil fuels. Recommendations and Outlook Although desalination technologies are energy intensive and provoke an important environmental load, they present a high potential in being reduced since: a) in the mid-term, it is to be expected that the different technologies could improve their efficiency significantly, b) the environmental loads would be highly reduced if the energy production models were not mainly based on fossil fuels and c) the energy consumption, particularly in the case of thermal desalination, can be drastically reduced when integrating desalination with other productive processes. The results presented in this paper indicate that a very interesting and promising field of research is available in order to reduce the environmental load of these vigorous and increasing desalination technologies.     

Life Cycle Assessment of Water Production Technologies - Part 2: Reverse Osmosis Desalination versus the Ebro River Water Transfer (9 pp)

- Preamble. This series of two papers analyses and compares the environmental loads of different water production technologies in order to establish, in a global, rigorous and objective way, the less aggressive technology for the environment with the present state of the art of technology. Further, an estimation of the potential environmental loads that the considered technologies could provoke in future is also presented, taking into account the most suitable evolution of the technology. - Part 1 presents the assessment of most commercial desalination technologies which are spread worldwide: Reverse Osmosis, Multi Effect Desalination and Multi Stage Flash. Part 2 presents the comparative LCA analysis of a big hydraulic infrastructure, as is to be found in the Ebro River Water Transfer project, with respect to desalination. - Intention, Goal and Background. In this paper some relevant results of a research work are presented, the main aim of which consists of performing the environmental assessment of different water production technologies in order to establish, in a global, rigorous and objective way, the less aggressive technology for the environment for supplying potable water to the end users. The scope of this paper is mostly oriented to the comparative Life Cycle Assessment of different water production technologies instead of presenting new advancements in the LCA methodology. Based on the results obtained in Part 1 (LCA of most widespread commercial desalination technologies), the particular case of a big hydraulic project, which is the Ebro River Water Transfer (ERWT) considered in the Spanish National Hydrologic Plan, versus the production by desalination of the same amount of water to be diverted, is compared in Part 2. The assessment technique is the Life Cycle Analysis (LCA), which includes the entire life cycle of each technology, encompassing: extraction and processing raw materials, manufacturing, transportation and distribution, operation and final waste disposal. Methods and Main Features. The software SimaPro 5.0, developed by Dutch PRé Consultants, has been used as the analysis tool, because it is a well known, internationally accepted and validated tool. Different evaluation methods have been applied in the LCA evaluation: CML 2 baseline 2000, Eco-Points 97 and Eco-Indicator 99. Data used in the inventory analysis of this Part 2 come from: a) desalination: data obtained for existing plants in operation; b) ERWT: Project approved in the Spanish National Hydrologic Plan and its Environmental Impact Evaluation and; c) data bases implemented in the SimaPro software – BUWAL 250, ETH-ESU 96, IDEMAT 2001. Different scenarios have been analyzed in both parts in order to estimate not only the potential of reduction of the provoked environmental loads with the present state of the art of technology, but also the most likely future trend of technological evolution. In Part 1, different energy production models and the integration of desalination with other productive processes are studied, while the effect of the most likely technological evolution in the midterm, and the estimation of the environmental loads to the water transfer during drought periods are considered in Part 2. Results and Discussion As proven in Part 1, RO is a less aggressive desalination technology for the environment. Its aggression is one order of magnitude lower than that of the thermal processes, MSF and MED. The main contribution to the global environmental impact of RO comes from the operation, while the other phases, construction and disposal, are almost negligible when compared to it. In the case of the ERWT, the contribution of the operation phase is also the most important one, but the construction phase has an important contribution too. Its corresponding environmental load, with the present state of the art of technology, is slightly lower than that provoked by the RO desalination technology. However, the results obtained in the different scenarios analyzed show that the potential reduction of the environmental load in the case of the ERWT is significantly lower than that in the case of the RO. The effect of drought periods in the assessed environmental loads of the water transfer is not negligible, obtaining as a result an increasing environmental load per m3 of diverted water. Conclusion The environmental load associated with RO, with the present state of the art of technology, is slightly higher than that provoked by the ERWT. However, considering the actual trend of technological improvement of the RO and the present trend of energy production technology in the address of reducing the fossil fuels\ contribution in the electricity production, the environmental load associated with RO in the short mid-term would be likely to be lower than that corresponding to the ERWT. Recommendations and Outlook Although desalination technologies are energy intensive and provoke an important environmental load, as already explained in Part 1, they present a high potential of reducing it. In respect to ERWT, the results indicate, when the infrastructure of ERWT is completed (by 2010–2012), that the LCA of RO will be likely to be against the water transfer. With the present technological evolution of water production technologies and from the results obtained in this paper, it seems, from an environmental viewpoint, that big hydraulic projects should be considered the last option because they are rigid and long-term infrastructures (several decades and even centuries of operation) that provoke important environmental loads with only a small margin for reducing them.     

Ecological Toxicity Methods and Metals. An examination of two case studies (8 pp + 1)

Goal, Scope and Background The Apeldoorn Workshop (April 15th, 2004, Apeldoorn, NL) brought together specialists in LCA and Risk Assessment to discuss current practices and complications of the life cycle impact assessment (LCIA) ecological toxicity (ecotox) methodologies for metals. The consensus was that the LCIA methods currently available do not appropriately characterize impacts of metals due to lack of fundamental metals chemistry in the models. A review of five methods available to perform ecotox impact assessment for metals has been prepared to provide Life Cycle Assessment (LCA) practitioners with a better understanding of the current state of the science and potential biases related to metals. The intent is to provide awareness on issues related to ecotox impact assessment. Methods In this paper two case studies, one a copper based product (copper tube), the other a zinc-based product (gutter systems), were selected and examined by applying freshwater ecological toxicity impact models – USES-LCA, Eco-indicator 99 (EI 99), IMPACT 2002, EDIP 97, and CalTOX-ETP. Both studies are recent, comprehensive, cradle-to-gate, and peer-reviewed. The objective is to review the LCIA results in the context of the practical concerns identified by the Apeldoorn Declaration, in particular illustrating any inconsistencies such as chemical characterization coverage, species specificity, and relative contribution to impact results. Results and Discussion The results obtained from all five of the LCIA methods for the copper tube LCI pointed to the same substance as being the most important – copper. This result was obtained despite major fundamental differences between the LCIA methods applied. However, variations of results were found when examining the freshwater ecological toxicity potential of zinc gutter systems. Procedural difficulties and inconsistencies were observed. In part this was due to basic differences in model nomenclature and differences in coverage (IMPACT 2002+ and EDIP 97 contained characterization factors for aluminium that resulted in 90% and 22% contribution to burden respectively, the other three methods did not). Differences were also observed relative to the emissions source compartment. In the case of zinc, air emissions were found to be substantial for some ecotox models, whereas, water emissions results were found to be of issue for others. Conclusions This investigation illustrates the need to proceed with caution when applying LCIA ecotox methodologies to life cycle studies that include metals. Until further improvements are made, the deficiencies should be clearly communicated as part of LCIA reporting. Business or policy decisions should not without further discussion be based solely on the results of the currently available methods for assessing ecotoxicity in LCIA. Outlook The outlook to remedy deficiencies in the ecological toxicity methods is promising. Recently, the LCIA Toxic Impacts Task Force of the UNEP/SETAC Life Cycle Initiative has formed a subgroup to address specific issues and guide the work towards establishment of sound characterization factors for metals. Although some measure of precision of estimation of potential impact has been observed, such as in the case of copper, accuracy is also a major concern and should be addressed. Further investigation through controlled experimentation is needed, particularly LCIs composed of a variety of inorganics as well as organics constituents. Support for this activity has come from the scientific community and industry as well. Broader aspects of structure and nomenclature are being collectively addressed by the UNEP/SETAC Life Cycle Initiative. These efforts will bring practical solutions to issues of naming conventions and LCI to LCIA flow assignments.     

Life Cycle Assessment of the Mobile Communication System UMTS: Towards Eco-efficient Systems (12 pp)

Goal, Scope and Background Goal of this study is an evaluation of the environmental sustainability of the UMTS mobile communication system in Switzerland by means of a Life Cycle Assessment (LCA). A baseline environmental impact profile across the full life cycle of the UMTS (Universal Mobile Telecommunication System) and its predecessor, the GSM (Global System for Mobile Communication) is presented. The baseline assessment was a necessary first step to evaluate the environmental impacts of the mobile communication systems use and growth, thus permitting the evaluation of its environmental sustainability. Main Features Two functional units are defined: a data set of 1 Gbit (1.000.000 kbit), and the yearly mobile communication of an average customer. In the UMTS, both data packages and calls can be conveyed. In order to be able to standardize the results, an equivalence between these two kinds of transmission is formed. Two different options are defined, which represent different ways of transferring the data: mobile phone to mobile phone, and mobile phone to fixed network. All components of the UMTS network like the mobile phones, base stations, antennae, switching systems and the components of the landline like cable system and switching centers, are assessed. The environmental impacts are assessed taking into account all major life cycle phases like raw material extraction, manufacturing, use, disassembly and disposal of the product and the needed infrastructure. Electronic components like printed wiring boards and integrated circuits are assessed using a simple model based on the size (for IC) or number of layers (for PWB), respectively. Mining of precious metals (gold, silver) is included. The study was carried out by ESU-services, Motorola, Swisscom and Deutsche Telekom. Thanks to the industrial partners it can rely on primary data for the production of mobile phone and base station, and for the operation of the networks. As the UMTS network is still being built, no actual data of network operation is available. Data from the GSM (Global System for Mobile Communication) were used in case of data gaps. Results and Conclusions About 25 kg CO2 are emitted and 800 MJ-eq (non-renewable) primary energy are required for the transfer of 1 Gbit information from mobile phone to mobile phone in the UMTS network. For a transfer from mobile to fixed network, these values are 20 kg CO2 and 640 MJ-eq, respectively. On the other hand, the fixed network requires more resources like copper (0.07 kg for the mobile to mobile option vs. 0.12 kg for mobile to fixed network). From an environmental point of view, the mobile telephone is the most important element of the mobile communication network (UMTS and GSM). The short service life of the mobile phone plays a substantial role. Increasing the utilization period of the mobile phone (e.g. by leasing, re-use, extension of the innovation cycles, etc.) could thus represent a large potential for its improvement. The second most important components are the base stations. In the assessment mainly the use phase proved to be important. The lower environmental impact (per Gbit data transfer) as compared to the mobile phone can be explained by the longer service life (around factor 8). Main impacts are caused by the electricity consumption, in particular the energy needed for cooling the base stations. By choosing an environmentally benign electricity mix and/or by increasing the portion of renewable sources of energy, the network operators have a substantial potential of lower the environmental impacts (in particular the greenhouse gas emissions) of mobile telecommunication. Furthermore, the manufacturing of electronic components, the life time of the appliances and energy consumption are key parameters influencing the environmental profile of the networks most. Given its larger data transfer rate, the UMTS is ecologically more favorable in terms of data transfer rate than its predecessor, the GSM system. The higher energy consumption and the more complex production of the devices in the UMTS system are compensated by the faster data transmission rate. Per customer, the result is inverse, however, since the higher efficiency is compensated by the higher data communication per user in the UMTS system. The UMTS network in its state of 2004 according to the 2001 planning and with the accordingly calculated number of customers and data transfer causes 2.1 times more CO2 emissions and requires 2.4 times more (non-renewable) primary energy per customer than for the GSM system in its current state. It must be noted, however, that the UMTS technology supports other services than the GSM system. The development of the UMTS is accompanied with an increased consumption of resources and emissions of pollutants and greenhouse gases regarding the entire system for mobile telephone communication. The GSM system is a mature technology, while the UMTS is still at the beginning of its learning curve. Thus, it can be safely assumed that large improvement potentials are still present for the UMTS network components concerning expenditures and emissions both at production and by the use of the devices. This study provides the necessary information where such improvements are most effective in environmental terms.     

3-(Cyclopropylmethyl)-7-((4-(4-[11C]methoxyphenyl)piperidin-1-yl)methyl)-8-(trifluoromethyl)-[1,2,4]triazolo[4,3-a]pyridine: Synthesis and preliminary evaluation for PET imaging of metabotropic glutamate receptor subtype 2

Selective metabotropic glutamate receptor 2 (mGluR2) inhibitors have been demonstrated to show therapeutic effects by improving alleviating symptoms of schizophrenic patients in clinical studies. Herein we report the synthesis and preliminary evaluation of a ¹¹C-labeled positron emission tomography (PET) tracer originating from a mGluR2 inhibitor, 3-(cyclopropylmethyl)-7-((4-(4-methoxyphenyl)piperidin-1-yl)methyl)-8-(trifluoromethyl)-[1,2,4]triazolo[4,3-a]pyridine (CMTP, 1a). [¹¹C]CMTP ([¹¹C]1a) was synthesized by O-[¹¹C]methylation of desmethyl precursor 1b with [¹¹C]methyl iodide in 19.7 ± 8.9% (n = 10) radiochemical yield (based on [¹¹C]CO₂) with >98% radiochemical purity and >74 GBq/μmol molar activity. Autoradiography study showed that [¹¹C]1a possessed moderate in vitro specific binding to mGluR2 in the rat brain, with a heterogeneous distribution of radioactive accumulation in the mGluR2-rich brain tissue sections, such as the cerebral cortex and striatum. PET study indicated that [¹¹C]1a was able to cross the blood–brain barrier and enter the brain, but had very low specific binding in the rat brain. Further optimization for the chemical structure of 1a is necessary to increase binding affinity to mGluR2 and then improve in vivo specific binding in brain.