Cumulative Exergy Extraction From The Natural Environment Research Articles

Environmental sustainability assessment of biodegradable bio-based poly(3-hydroxybutyrate-co-3-hydroxyvalerate) from agro-residues: Production and end-of-life scenarios

In the context of a circular bio-based economy, more public attention has been paid to the environmental sustainability of biodegradable bio-based plastics, particularly plastics produced using emerging biotechnologies, e.g. poly(3-hydroxybutyrate-co-3-hydroxyvalerate) or PHBV. However, this has not been thoroughly investigated in the literature. Therefore, this study aimed to address three aspects regarding the environmental impact of PHBV-based plastic: (i) the potential environmental benefits of scaling up pellet production from pilot to industrial scale and the environmental hotspots at each scale, (ii) the most favourable end-of-life (EOL) scenario for PHBV, and (iii) the environmental performance of PHBV compared to benchmark materials considering both the pellet production and EOL stages. Life cycle assessment (LCA) was implemented using Cumulative Exergy Extraction from the Natural Environment (CEENE) and Environmental Footprint (EF) methods. The results show that, firstly, when upscaling the PHBV pellet production from pilot to industrial scale, a significant environmental benefit can be achieved by reducing electricity and nutrient usage, together with the implementation of better practices such as recycling effluent for diluting feedstock. Moreover, from the circularity perspective, mechanical recycling might be the most favourable EOL scenario for short-life PHBV-based products, using the carbon neutrality approach, as the material remains recycled and hence environmental credits are achieved by substituting recyclates for virgin raw materials. Lastly, PHBV can be environmentally beneficial equal to or even to some extent greater than common bio- and fossil-based plastics produced with well-established technologies. Besides methodological choices, feedstock source and technology specifications (e.g. pure or mixed microbial cultures) were also identified as significant factors contributing to the variations in LCA of (bio)plastics; therefore, transparency in reporting these factors, along with consistency in implementing the methodologies, is crucial for conducting a meaningful comparative LCA.

Resource Use and Environmental Impacts of Seed and Vegetative Globe Artichoke Production in Mediterranean Environments: A Cradle-to-Farm Gate Analysis

Globe artichoke is propagated by seed (seed propagated, SP) or by plant (vegetative propagated, VP). To date, there is a lack of knowledge of how the propagation system affects the life cycle resource use and environmental performance of globe artichoke production. We combined energetic, exergetic, and environmental life cycle assessment (LCA) to explore “cradle-to-farm gate” resource use and environmental impacts of Mediterranean globe artichoke production using VP and SP. The cumulative energy and exergy were calculated using cumulative energy demand (CED) and cumulative exergy extraction from the natural environment (CEENE). The environmental impacts classified in different impact categories were assessed using the ReCiPe 2016 method. The functional units were 1 ton of artichoke heads (reflecting production efficiency) and 1 ha of cropped land (reflecting production intensity). The results show that the VP globe artichoke generate 14% lower CED (64,212 vs. 75,212 MJ ha−1) and 17% lower CEENE (88,698 vs. 106,664 MJexha−1) per 1 ha of land while 1 ton of product generates higher impact: 29% CED (5384.4 MJ vs. 4178.5 MJ ton−1) and 25% CEENE (7391.5 vs. 5927 MJex ton−1). On a mass basis, SP artichokes had lower water consumption (−18%), freshwater and marine ecotoxicity (−47%), and stratospheric ozone depletion (−32%), but a higher global warming (+19%), fossil (+36%) and mineral scarcity (+39%), and human toxicity-related impacts (+27%). At the endpoint level, VP globe artichoke has higher damage to human health (+13.4%) and ecosystem quality (+20.5%), but lower to resource availability (−24.5%). The single-score LCA analysis indicated that SP globe artichokes generate a 24% higher impact per 1 ha (1911.3 vs. 1452.7 points) but 14% less per unit of product (106 vs. 121.1 points). For both systems, water and fertilizer should be used more carefully and efficiently since the application of irrigation, fuel, and fertilizers were the major contributors to total environmental damage.

Analysis of environmental sustainability of e-waste in developing countries — a case study from Pakistan

The electronic waste generation rate is increasing drastically at a rate of 3 to 5% per year in developing countries. The aim of this study is to analyze the environmental sustainability and economic benefits of such e-waste management in the developing economies like Pakistan. The life cycle assessment (LCA) method has been employed for streamlined impact analysis of the end-of-life processing of e-waste focusing mainly on laptop computers and liquid crystal display (LCD) desktop computers in Pakistan. The method of cumulative exergy extraction from the natural environment (CEENE) has also been deployed for the relative assessment of resources' consumption of e-waste recycling versus landfilling scenario. The determined impact scores are 1.79E + 03kg CO2 eq., 7.19E-07kg CFC-11eq., 1.02E + 03kg 1,4-DCB, 7.13E + 01kg 1,4-DCB, and 3.41E-03kg Cu eq. in climate change potential, stratospheric ozone depletion, ecotoxicity potential, human noncarcinogenic potential, and mineral resource depletion impact categories, respectively. The results of CEENE analysis reveal that approximately 80% of the impact on natural resources is reduced by the efficient recycling of e-waste. The comparative assessment of respective scores for current and target material weight recovery (MWR) indicators represented that by increasing the MWR indicator by 33.8% for laptop computers and by 27.2% for LCD computers, the country will achieve an annual economic benefit of US $191.56 million. This is greatly significant for a transitional shift towards e-waste revalorization while realizing the objectives of sustainable resource consumption. Innovative improvement measures ensuring economically feasible, energy-efficient, and environment friendly waste collection, treatment, and recycling practices present an invaluable opportunity for developing countries.

Eco-thermodynamics of hydrogen production by high-temperature electrolysis using solid oxide cells

In this study, Solar Energy Demand (SED), Cumulative Exergy Extraction from the Natural Environment (CEENE), and LCA-ReCiPe 2016 (using both midpoint and endpoint modeling) life cycle impact assessment methods has been used to assess the performance of hydrogen (H2) production with renewable and non-renewable electricity sources via high-temperature Solid Oxide Electrolysis Cells. The analysis identified most relevant impact categories, life cycle stages, and processes, both from a thermodynamic and an environmental viewpoint. Electrolysis with non-renewable energy is characterized by the greatest environmental burdens, however, renewable energy systems also have considerable environmental impacts, some of which are significant. While no perfect electricity source exists, a growing portion of the renewable-based electricity production in the grid mix is an attractive option to lower environmental impacts of H2 production. Irrespective of the evaluation method, the contribution analysis from different life-cycle stages shows and confirm that the major contributor to the environmental burdens is the electricity supply. The manufacturing stage has high relevance for mineral and metal resources and toxicity-related impacts. Calculations of grid-based electrolysis life cycle environmental impacts in some European countries showed that significant variations. For example, global warming potential per kgH2 produced vary between 3.31 and 48.24 kgCO2. Trade-off analysis between the midpoint and endpoint indicators revealed that water consumption, global warming, and particulate matter formation, play a major role in the ranking of electricity supply options. The findings suggest that all potential impacts both at the midpoint and endpoint level should be considered to ensure robust results of the LCA evaluation, a fair comparison between pathways towards more transparent and evidence-based decisions. Towards that end, a further country site-specific assessment with optimization strategies and integration of traditional LCA with resource accounting (thermodynamic metrics) will need to be developed to explore additional valuable insights towards sustainable electrolytic H2 production systems.

Exergetic, environmental and economic sustainability assessment of stationary Molten Carbonate Fuel Cells

In this study, exergetic, environmental and economic (3E) analyses have been performed in order to provide sustainability indicators from resource extraction to the final product of stationary power Molten Carbonate Fuel Cells (MCFC) systems (500 kW). Two environmental life cycle impact assessment methods have been selected: the ReCiPe 2016 hierarchical midpoint and endpoint, and the Cumulative Exergy Extraction from the Natural Environment (CEENE). The levelized cost of electricity (LCOE) under technology cost and performance parameters was calculated to analyze the system from the economic point of view. The global warming potential (GWP) is estimated to be 0.549 kg CO2-eq/kWh while acidification (5.06e−4 kg SO2-eq/kWh), eutrophication (9.81e−4 kg P-eq. freshwater/kWh), ozone layer depletion (4.11e−6 kg CFC-11-eq/kWh) and human toxicity (1.07 kg 1,4-DB-eq/kWh). Aggregated CEENE was estimated to be about 8.55 MJex/kWh. Results show that majority of impacts are dominated by fuel supply, while some others are dominated by manufacturing of system. GWP is the only impact category dominated by system operation. Due to potentially high electrical efficiency, MCFC energy systems can lead to lower CEENE and improvements of global warming, fossil fuel and resource scarcity, and photochemical oxidant formation potential with respect to other conventional energy conversion systems. Advances in longer lifetimes of the MCFC stack can help trigger innovation in manufacturing processes and will lead to less resource use of electricity, metal, and minerals, thus less resource scarcity and toxicity related burdens. The baseline LCOE is calculated 0.1265 €/kWh being comparable with the Italian grid (0.15–0.16 €/kWh). The costing results indicate that the unit decreasing the system capital cost could potentially reduce the LCOE by around 25%. Advancing the use of life-cycle thinking in MCFC industry with site-specific data raise systems credibility and enables clarifying the trade-offs between the sustainability pillars, thus designing more sustainable products.

Performance indicators for a circular economy: A case study on post-industrial plastic waste

A linear economy approach results in many environmental challenges: resources become depleted and end up as waste and emissions. One of the key strategies to overcome these problems is using waste as a resource, i.e. evolving toward a circular economy. To monitor this transition, suitable indicators are needed that focus on sustainability issues whilst taking into account the technical reality. In this paper, we develop such an indicator to quantify the circular economy performance of different plastic waste treatment options. This indicator is based on the technical quality of the plastic waste stream and evaluates resource consumption by using the Cumulative Exergy Extraction from the Natural Environment (CEENE) method. To illustrate the use of this new indicator, it was applied in a case study on post-industrial plastic waste treatment. The results show that the indicator can be a very useful approach to guide waste streams towards their optimal valorization option, based on quality of the waste flow and the environmental benefit of the different options.

Environmental life cycle assessment of grain maize production: An analysis of factors causing variability

To meet the growing demand, high yielding, but environmentally sustainable agricultural plant production systems are desired. Today, life cycle assessment (LCA) is increasingly used to assess the environmental impact of these agricultural systems. However, the impact results are very diverse due to management decisions or local natural conditions. The impact of grain maize is often generalized and an average is taken. Therefore, we studied variation in production systems. Four types of drivers for variability are distinguished: policy, farm management, year-to-year weather variation and innovation. For each driver, scenarios are elaborated using ReCiPe and CEENE (Cumulative Exergy Extraction from the Natural Environment) to assess the environmental footprint. Policy limits fertilisation levels in a soil-specific way. The resource consumption is lower for non-sandy soils than for sandy soils, but entails however more eutrophication. Farm management seems to have less influence on the environmental impact when considering the CEENE only. But farm management choices such as fertiliser type have a large effect on emission-related problems (e.g. eutrophication and acidification). In contrast, year-to-year weather variation results in large differences in the environmental footprint. The difference in impact results between favourable and poor environmental conditions amounts to 19% and 17% in terms of resources and emissions respectively, and irrigation clearly is an unfavourable environmental process. The best environmental performance is obtained by innovation as plant breeding results in a steadily increasing yield over 25years. Finally, a comparison is made between grain maize production in Flanders and a generically applied dataset, based on Swiss practices. These very different results endorse the importance of using local data to conduct LCA of plant production systems. The results of this study show decision makers and farmers how they can improve the environmental performance of agricultural systems, and LCA practitioners are alerted to challenges due to variation.

Evaluation of Abiotic Resource LCIA Methods

In a life cycle assessment (LCA), the impacts on resources are evaluated at the area of protection (AoP) with the same name, through life cycle impact assessment (LCIA) methods. There are different LCIA methods available in literature that assesses abiotic resources, and the goal of this study was to propose recommendations for that impact category. We evaluated 19 different LCIA methods, through two criteria (scientific robustness and scope), divided into three assessment levels, i.e., resource accounting methods (RAM), midpoint, and endpoint. In order to support the assessment, we applied some LCIA methods to a case study of ethylene production. For RAM, the most suitable LCIA method was CEENE (Cumulative Exergy Extraction from the Natural Environment) (but SED (Solar Energy Demand) and ICEC (Industrial Cumulative Exergy Consumption)/ECEC (Ecological Cumulative Exergy Consumption) may also be recommended), while the midpoint level was ADP (Abiotic Depletion Potential), and the endpoint level was both the Recipe Endpoint and EPS2000 (Environmental Priority Strategies). We could notice that the assessment for the AoP Resources is not yet well established in the LCA community, since new LCIA methods (with different approaches) and assessment frameworks are showing up, and this trend may continue in the future.

Resource savings by urban mining: The case of desktop and laptop computers in Belgium

Waste electrical and electronic equipment (WEEE) has become increasingly important over the last years. Additionally, the European Union recognizes the growing importance of raw materials, and the crucial role of recycling. In this study the performance of WEEE recycling was assessed for the case of desktop and laptop computers in Belgium in 2013. The analysis was performed in four steps. First, the recycling chain is analyzed through material flow analysis (MFA) at the level of specific materials. Second, an indicator is calculated, which quantifies the effectively recycled weight ratios of the specific materials. Third, a second indicator expresses the recycling efficiency of so-called critical raw materials. Finally, the natural resource consumption of the recycling scheme in a life cycle perspective is calculated using the Cumulative Exergy Extraction from the Natural Environment (CEENE) method, and is benchmarked with a landfill scenario. Overall, the results show that base metals such as ferrous metals, aluminium and copper are recycled to a large extent, but that for precious metals improvements still can be made. The input of criticality (arising from the incoming mass, as well as the individual criticality value of the assessed material) mainly comes from base metals, resulting in a high recovery performance of raw materials criticality. Finally, the natural resource consumption of the recycling scenario is much smaller than in case of landfilling the WEEE: 80 and 87% less resource consumption is achieved for desktops and laptops respectively, hence saving significant primary raw materials.

Resource recovery from residual household waste: An application of exergy flow analysis and exergetic life cycle assessment

Exergy is based on the Second Law of thermodynamics and can be used to express physical and chemical potential and provides a unified measure for resource accounting. In this study, exergy analysis was applied to four residual household waste management scenarios with focus on the achieved resource recovery efficiencies. The calculated exergy efficiencies were used to compare the scenarios and to evaluate the applicability of exergy-based measures for expressing resource quality and for optimizing resource recovery. Exergy efficiencies were determined based on two approaches: (i) exergy flow analysis of the waste treatment system under investigation and (ii) exergetic life cycle assessment (LCA) using the Cumulative Exergy Extraction from the Natural Environment (CEENE) as a method for resource accounting. Scenario efficiencies of around 17–27% were found based on the exergy flow analysis (higher efficiencies were associated with high levels of material recycling), while the scenario efficiencies based on the exergetic LCA lay in a narrow range around 14%. Metal recovery was beneficial in both types of analyses, but had more influence on the overall efficiency in the exergetic LCA approach, as avoided burdens associated with primary metal production were much more important than the exergy content of the recovered metals. On the other hand, plastic recovery was highly beneficial in the exergy flow analysis, but rather insignificant in exergetic LCA. The two approaches thereby offered different quantitative results as well as conclusions regarding material recovery. With respect to resource quality, the main challenge for the exergy flow analysis is the use of exergy content and exergy losses as a proxy for resource quality and resource losses, as exergy content is not per se correlated with the functionality of a material. In addition, the definition of appropriate waste system boundaries is critical for the exergy efficiencies derived from the flow analysis, as it is constrained by limited information available about the composition of flows in the system as well as about secondary production processes and their interaction with primary or traditional production chains. In the exergetic LCA, resource quality could be reflected by the savings achieved by product substitution and the consideration of the waste’s upstream burden allowed for an evaluation of the waste’s resource potential. For a comprehensive assessment of resource efficiency in waste LCA, the sensitivity of accounting for product substitution should be carefully analyzed and cumulative exergy consumption measures should be complimented by other impact categories.

Resource use profile and nutritional value assessment of a typical Belgian meal, catered or home cooked, with pork or Quorn™ as protein source

The nutritional value of food and its environmental impact have received considerable attention, however an assessment of environmental sustainability of catered meals is lacking. We therefore assessed the nutritional value and resource consumption of a specific catered meal, pork tenderloin with potato croquettes, carrots and mushroom sauce (‘Canteen Pork’). The outcomes are compared with that of an identical meal cooked at home (‘Home’), for which ‘Low’ and ‘High’ scoring hypothetical alternatives were defined (e.g. whether or not frying oil as a waste product was reprocessed or recycled), as well as with that of a vegetarian alternative: Quorn™. The resource consumption impact is assessed from cradle-to-disposal, expressed as the Cumulative Exergy Extraction from the Natural Environment (CEENE). Exergy is the amount of useful energy. The CEENE approach accounts for all resource types and is unique since it considers the deprived natural net primary production (expressed in exergy) as the impact for human land occupation, highly relevant for crop and thus food production. The food production, processing and packaging stage accounts for the largest amount of resource consumption compared to food preparation and waste management. The ‘Home Pork High’ scenario has the highest resource consumption at 83 MJex meal−1. ‘Home Pork Low’, ‘Home Quorn™ High’, ‘Canteen Pork’, ‘Home Quorn™ Low’ and ‘Canteen Quorn’ have a 15, 18, 26, 32 and 40% lower resource consumption compared to ‘Home Pork High’, respectively. For all scenarios, biomass resources contribute 52–64% of the total CEENE, mainly through land occupation. The nutritional analysis, via nutritional density scoring (the higher the better), resulted in a score of 18.1 and 31.2 for the ‘Home Quorn Low’ and ‘High’, 10.4 and 23.4 for the ‘Home Pork High’ and ‘Low’ scenario and 17.0 and 27.3 for the ‘Canteen Pork’ and ‘Canteen Quorn™’, respectively. To conclude, the vegetarian meal scores best on both attributes, however, this effect diminishes considerably if one considers outcomes per energy or protein amount. With regards to catered vs home cooked meals, resource consumption is lower in canteen prepared meals than in the case of the home-cooked meal. However, the nutritional value can be lower or higher depending on consumer behaviour, namely the extent of the use, type and application of butter is key in altering this result.

Comparative environmental life cycle assessment of two seaweed cultivation systems in North West Europe with a focus on quantifying sea surface occupation

Environmental concerns regarding natural resource depletion have led to the cultivation of more renewable resources such as seaweed biomass. As the cultivation in Europe is still in its early stages, an estimation of the environmental sustainability may boost further development of this sector by highlighting its competitiveness. A case study on the resource footprint of Saccharina latissima production near the West coast of Ireland (18ha of floating longlines) and France (0.6ha of raft systems) is performed. The Cumulative Exergy Extraction from the Natural Environment (CEENE) method is used to quantify the exergy deprived from 8 types of natural resources (incl. marine resources) to produce 1MJex biomass. For Ireland and France, results of the Exergetic Life Cycle Assessment (ELCA) are 1.7MJexMJex−1 and 8.7MJexMJex−1, respectively. Compared to the footprint of microalgae and several terrestrial plants (sugar beets, maize and potatoes), typically showing values in the range of 0.92–3.88MJexMJex−1, seaweed production in North West Europe (especially in Ireland) is relatively resource-efficient. Moreover, the potential to improve the resource footprint of seaweed production is investigated; in the short-term, seaweed can be cultivated with a comparable life cycle resource demand as several land plants.

Resource consumption assessment of Pangasius fillet products from Vietnamese aquaculture to European retailers

Concerns have risen regarding the environmental sustainability of favourable aquaculture-based products, including Pangasius fillets in modified atmosphere packaging (MAP). This study examines issues stemming from resource consumption in a cradle-to-factory gate life cycle analysis of MAP Pangasius, which includes aquaculture, processing living fish to frozen fillets in Vietnam, oceanic transport and processing frozen fillets to MAP in Belgium (Europe). Analysis was performed at the process level using Exergy Flow Analysis (ExFA) and from a life cycle perspective through the Cumulative Exergy Extraction from the Natural Environment (CEENE). The CEENE of MAP equals 669 GJ per tonne of dry matter (DM) of MAP Pangasius. Aquaculture, which is addressed in Huysveld et al. (2013), contains the largest share of the CEENE value (76%), and the three subsequent phases contribute 13%, 5% and 6%, respectively. Consequently, MAP production requires significant amounts of land (42%, primarily for the cultivation of crop-based feed ingredients), water (31%, primarily for pond water renewal) and fossil fuels (21%, primarily for energy demand in processing and transport). Regarding processing and transport, further attention should be paid to the consumption of electricity, water and packaging materials. Improvements should focus on lowering the fillet weight gain due to glazing and/or soaking and on the use and disposal of packaging materials, particularly those used to ship the frozen fillets. Recycling in Belgium reduces 40 GJ per tonne of DM of MAP via replacement of virgin material. MAP Pangasius creates half the resource footprint compared to fresh chicken meat locally produced in Europe despite being imported from Vietnam; this is explained by the lower Feed Conversion Ratio of Pangasius and by the utilization of Pangasius by-products for animal feed in Vietnam, whereas chicken by-products are considered wastes and are incinerated in Europe.

Accounting for the occupation of the marine environment as a natural resource in life cycle assessment: An exergy based approach

The human population is rising and the availability of terrestrial land and its resources are finite and, perhaps, not sufficient to deliver enough food, energy, materials and space. Thus, it is important to (further) explore and exploit the marine environment which covers no less than 71% of the earth's surface. The marine environment is very complex but can roughty be divided into two systems: natural (e.g. wild fishing) and human-made (e.g. artificial islands). In this study, characterization factors (CF) for natural and human-made marine systems were calculated in order to be able to assess the environmental impact of occupying marine surfaces, which was not possible so far in life cycle assessment. When accounting for natural resources while occupying one of these systems, it is important to consider the primary resources that are actually deprived from nature, which differs between the natural and human-made marine systems.In natural systems, the extracted biomass was accounted for through its exergy content, which is the maximum quantity of work that the system can execute in its environment. Reference flows for marine fish, seaweeds, crustaceans and mollusks were proposed and their correlated CF was calculated. For human-made systems, the deprived land resource is, in fact, the occupied area of the marine surface. Based on potential marine net primary production data (NPP), exergy based spatial and temporal CFs for ocean areal occupation were calculated. This approach was included in the Cumulative Exergy Extraction from the Natural Environment (CEENE) method which makes it the first life cycle impact assessment (LCIA) method capable of analyzing the environmental impact (and more specific the resource footprint) of marine areal occupation. Furthermore, the methodology was applied to two case studies: comparing resource consumption of on- and offshore oil production, and fish and soybean meal production for fish feed applications.

Resource use analysis of Pangasius aquaculture in the Mekong Delta in Vietnam using Exergetic Life Cycle Assessment

Depletion of marine fish stocks has become a global problem. Aquaculture is seen by many as the best way to meet the growing demand for fish products. The question then arises whether aquaculture is a truly environmentally sustainable alternative. Every type of aquaculture is different, therefore each one merits its own case study. To date, Life Cycle Assessment (LCA) studies have mainly examined Western culture systems, although Asia predominates the world aquaculture production by quantity. In this research, we focus on a vertically integrated Vietnamese top exporter of Pangasius food products in the Mekong Delta. Along with a tremendous expansion of this sector in recent decades, intensification coincided with an increased material and energy demand. Therefore, we focus on resource extraction (from cradle to farm gate), expressed as the Cumulative Exergy Extraction from the Natural Environment (CEENE). Hotspots in resource demand are identified over the life cycle stages (juvenile production, feed production and culturing to marketable-sized fish). The life cycle resource footprint includes mainly land (62%, mainly for feed production), water (31%, mainly for on-site farming of the fish) and fossil fuels (4%, mainly for energy needs throughout the feed supply chain). Main methods for reducing this resource demand should be lowering the feed and water input into the ponds and improving the efficiency of the feed supply chain. Pros and cons of closed-loop water-saving systems are discussed. The feed supply chain plays a key role in improving the resource use efficiency. Vietnamese Pangasius producers should be introduced to life cycle thinking and encouraged to pay attention to the environmental performance of their suppliers across the world. For the last goal, a new metric system to score the Feed Conversion Ratio (FCR), i.e. the CEENE FCR, is introduced here.

Assessment of the overall resource consumption of germanium wafer production for high concentration photovoltaics

The overall resource requirements for the production of germanium wafers for III–V multi-junction solar cells applied in concentrator photovoltaics have been assessed based on up to date process information. By employing the cumulative energy demand (CED) method and the cumulative exergy extraction from the natural environment (CEENE) method the following resources have been included in the assessment: fossil resources, nuclear resources, renewable resources, land resources, atmospheric resources, metal resources, mineral resources and water resources. The CED has been determined as 216 MJ and the CEENE has been determined as 258 MJ ex. In addition partial energy and exergy payback times have been calculated for the base case, which entails the installation of the high concentration photovoltaics (HCPVs) in the Southwestern USA, resulting in payback times of around 4 days for the germanium wafer production. Due to applying concentration technology the germanium wafer accounts for only 3% of the overall resource consumption of an HCPV system. A scenario analysis on the electricity input to the wafer production and on the country of installation of the HCPV has been performed, showing the importance of these factors on the cumulative resource consumption of the wafer production and the partial payback times.

Cumulative Exergy Extraction from the Natural Environment (CEENE): a comprehensive Life Cycle Impact Assessment method for resource accounting

The objective of the paper is to establish a comprehensive resource-based life cycle impact assessment (LCIA) method which is scientifically sound and that enables to assess all kinds of resources that are deprived from the natural ecosystem, all quantified on one single scale, free of weighting factors. The method is based on the exergy concept. Consistent exergy data on fossils, nuclear and metal ores, minerals, air, water, land occupation, and renewable energy sources were elaborated, with well defined system boundaries. Based on these data, the method quantifies the exergy "taken away" from natural ecosystems, and is thus called the cumulative exergy extraction from the natural environment (CEENE). The acquired data set was coupled with a state-of-the art life cycle inventory database, ecoinvent. In this way, the method is able to quantitatively distinguish eight categories of resources withdrawn from the natural environment: renewable resources, fossil fuels, nuclear energy, metal ores, minerals, water resources, land resources, and atmospheric resources. Third, the CEENE method is illustrated for a number of products that are available in ecoinvent, and results are compared with common resource oriented LCIA methods. The application to the materials in the ecoinvent database showed that fossil resources and land use are of particular importance with regard to the total CEENE score, although the other resource categories may also be significant.

Automated dosimetry using radiation sensitive films and validation of routine dosimetry data

The nutritional value of food and its environmental impact have received considerable attention, however an assessment of environmental sustainability of catered meals is lacking. We therefore assessed the nutritional value and resource consumption of a specific catered meal, pork tenderloin with potato croquettes, carrots and mushroom sauce (‘Canteen Pork’). The outcomes are compared with that of an identical meal cooked at home (‘Home’), for which ‘Low’ and ‘High’ scoring hypothetical alternatives were defined (e.g. whether or not frying oil as a waste product was reprocessed or recycled), as well as with that of a vegetarian alternative: Quorn™. The resource consumption impact is assessed from cradle-to-disposal, expressed as the Cumulative Exergy Extraction from the Natural Environment (CEENE). Exergy is the amount of useful energy. The CEENE approach accounts for all resource types and is unique since it considers the deprived natural net primary production (expressed in exergy) as the impact for human land occupation, highly relevant for crop and thus food production. The food production, processing and packaging stage accounts for the largest amount of resource consumption compared to food preparation and waste management. The ‘Home Pork High’ scenario has the highest resource consumption at 83 MJex meal−1. ‘Home Pork Low’, ‘Home Quorn™ High’, ‘Canteen Pork’, ‘Home Quorn™ Low’ and ‘Canteen Quorn’ have a 15, 18, 26, 32 and 40% lower resource consumption compared to ‘Home Pork High’, respectively. For all scenarios, biomass resources contribute 52–64% of the total CEENE, mainly through land occupation. The nutritional analysis, via nutritional density scoring (the higher the better), resulted in a score of 18.1 and 31.2 for the ‘Home Quorn Low’ and ‘High’, 10.4 and 23.4 for the ‘Home Pork High’ and ‘Low’ scenario and 17.0 and 27.3 for the ‘Canteen Pork’ and ‘Canteen Quorn™’, respectively. To conclude, the vegetarian meal scores best on both attributes, however, this effect diminishes considerably if one considers outcomes per energy or protein amount. With regards to catered vs home cooked meals, resource consumption is lower in canteen prepared meals than in the case of the home-cooked meal. However, the nutritional value can be lower or higher depending on consumer behaviour, namely the extent of the use, type and application of butter is key in altering this result.