Life Cycle Assessment (LCA) of a food-production system in Spain: Iberian ham based on an extensive system.

Taking into account that in the literature on pork-production Life Cycle Assessment (LCA) there are a few studies about the Iberian pig, the present article evaluates an extensive (growing-fattening) Iberian-pig system in Spain, producing meat for Iberian ham and other quality-labelled products. The study has been based on Cumulative Energy Demand (CED), Global Warming Potential (GWP), ReCiPe (midpoint; endpoint) and USEtox (human toxicity; ecotoxicity). The analysis involves feed (for pigs and piglets), transportation, drinking water, straw usage and building materials (concrete). The impacts have been evaluated per kg of live or carcass weight (two functional units). The results show that the total impacts (per kg of live or carcass weight) range from: 1) 22.05 to 28.19 MJprim (CED), 2) 4.37 to 6.19 kg CO2.eq (GWP 20a, 100a and 500a), 3) 0.86 to 1.08 Pts (ReCiPe endpoint single-score, involving Human health, Ecosystems and Resources), 4) 9.9 × 10-6 to 1.2 × 10-5 DALY (ReCiPe endpoint with characterisation), 5) 2.8 × 10-7 to 3.5 × 10-7 (species.yr) (ReCiPe endpoint with characterisation), 6) 10.12 to 12.66 CTUe (USEtox: ecotoxicity). Overall, the results show that the feed for the pigs is responsible for the major part of the environmental impacts. More analytically, maize and soya are the components with the highest environmental impacts due to factors such as transportation, use of fertilisers and diesel fuel. The discussion about pig-production environmental impacts and the role of extensive pig farming is enriched with comparisons with the literature on pig-production LCA. Critical parameters are identified and discussed, with the aim of proposing solutions to reduce pork-production environmental impacts. Finally, the usefulness of the present study and future prospects are presented.

Stacked volume holographic gratings for extending the operational wavelength range in LED and solar applications.

A novel stacking procedure is presented for volume phase holographic gratings (VPHGs) recorded in photopolymer material using Corning Willow Glass as a flexible substrate in order to achieve broader angular and spectral selectivity in a diffractive device with high efficiency for solar and LED applications. For the first time to our knowledge, we have shown a device designed for use with a white LED that has the same input and output angles and high efficiency when illuminated by different wavelengths. In this paper, two VPHGs were designed, experimentally recorded, and tested when illuminated at normal incidence. The experimental approach is based on stacking two individual gratings in which the spatial frequency and slant have been tailored to the target wavelength and using real-time on-Bragg monitoring of the gratings in order to control the recorded refractive index modulation, thereby optimizing each grating efficiency for its design wavelength. Lamination of the two gratings together was enabled by using a flexible glass substrate (Corning Willow Glass). Recording conditions were studied in order to minimize the change in diffraction efficiency and peak diffraction angle during lamination and bleaching. The final fabricated stacked device was illuminated by a white light source, and its output was spectrally analyzed. Compared to a single grating, the stacked device demonstrated a twofold increase in angular and wavelength range. The angular and wavelength selectivity curves are in good agreement with the theoretical prediction for this design. This approach could be used to fabricate stacked lenses for white light LED or solar applications.

Storage systems for building-integrated photovoltaic (BIPV) and building-integrated photovoltaic/thermal (BIPVT) installations: Environmental profile and other aspects.

In recent years there has been an increasing interest in Building-Integrated Photovoltaic (BIPV) and Building-Integrated Photovoltaic/Thermal (BIPVT) systems since they produce clean energy and replace conventional building envelope materials. By taking into account that storage is a key factor in the effective use of renewable energy, the present article is an overview about storage systems which are appropriate for BIPV and BIPVT applications. The literature review shows that there are multiple storage solutions, based on different kinds of materials (batteries, Phase Change Material (PCM) components, etc.). In terms of BIPV and BIPVT with batteries or PCMs or water tanks as storage systems, most of the installations are non-concentrating, façade- or roof-integrated, water- or air-based (in the case of BIPVT) and include silicon-based PV cells, lead-acid or lithium-ion batteries, paraffin- or salt-based PCMs. Regarding parameters that affect the environmental profile of storage systems, in the case of batteries critical factors such as material manufacturing, accidental release of electrolytes, inhalation toxicity, flammable elements, degradation and end-of-life management play a pivotal role. Regarding PCMs, there are some materials that are corrosive and present fire-safety issues as well as high toxicity in terms of human health and ecosystems. Concerning water storage tanks, based on certain studies about tanks with volumes of 300 L and 600 L, their impacts range from 5.9 to 11.7 GJprim and from 0.3 to 1.0 t CO2.eq. Finally, it should be noted that additional storage options such as Trombe walls, pebble beds and nanotechnologies are critically discussed. The contribution of the present article to the existing literature is associated with the fact that it presents a critical review about storage devices in the case of BIPV and BIPVT applications, by placing emphasis on the environmental profile of certain storage materials.

Biogas production by means of an anaerobic-digestion plant in France: LCA of greenhouse-gas emissions and other environmental indicators.

The present article assesses the environmental profile of a real-scale anaerobic-digestion plant that has been developed in France. The system utilises 13652 t of different types of feedstock related to food industry, agriculture, etc. The study is based on Life Cycle Assessment (LCA) according to Global Warming Potential (GWP), Cumulative Energy Demand (CED), ReCiPe midpoint/endpoint and USEtox. The life-cycle inventory includes real data from various sources of waste as well as the transportation distances. By considering the impact of both anaerobic digestion and transportation for the whole system, the following findings have been found: 6430 t CO2.eq (GWP 100a); 67194 GJprim (CED); 231100 Pts (ReCiPe endpoint single-score: Human health), 146932 Pts (ReCiPe endpoint single-score: Ecosystems), 171568 Pts (ReCiPe endpoint single-score: Resources). Furthermore, USEtox results, for the whole system and by taking into account both anaerobic digestion and transportation, show that based on: 1) Human toxicity/cancer, anaerobic-digestion phase has around 21 times higher value comparing to transportation, 2) Ecotoxicity, anaerobic-digestion phase presents about 77 times higher value than transportation. Regarding the impact of both phases (anaerobic digestion; transportation) per t of waste or per MWh of electricity, the findings show values of 0.5-0.6 t CO2.eq per t of feedstock (or digestate) or per MWh of electricity produced (not net). A separate subsection with comparisons of the present findings with literature studies about LCA of anaerobic-digestion plants has been included. In general, a good agreement has been observed. Moreover, comparisons of the impact of the electricity produced by means of the present biogas system with the impact of conventional electricity mixes of several countries are presented and discussed, proving the environmental benefits of the proposed anaerobic-digestion plant.

Building-Integrated Photovoltaic/Thermal (BIPVT): LCA of a façade-integrated prototype and issues about human health, ecosystems, resources.

Building-Integrated Photovoltaic/Thermal (BIPVT) technology offers multiple advantages; however, these types of installations include materials such as Photovoltaic (PV) cells and metals which considerably influence BIPVT environmental impact. Therefore, there is a need to evaluate BIPVT environmental profile, for instance by means of Life Cycle Assessment (LCA). In light of the issues mentioned above, the present article is an LCA study that assesses the environmental performance of a BIPVT prototype that has been developed and patented at the Ulster University (Belfast, UK). The investigation places emphasis on material manufacturing, based on Cumulative Energy Demand (CED), Global Warming Potential (GWP), ReCiPe, Ecological footprint and USEtox. The results show that according to all the adopted methods/environmental indicators and based on primary materials, the PV cells and the two vessels (steel) are the components with the three highest impacts. Scenarios which include recycling of steel, plastics and brass (landfill for the other materials has been assumed), based on CED, GWP 100a and ReCiPe endpoint, have been examined. It was found that steel recycling offers a considerable impact reduction, ranging from 47% to 85%. Furthermore, the impact of the proposed BIPVT module per m2 of thermal absorber has been calculated. The results, based on primary materials, show 4.92 GJprim/m2 and 0.34 t CO2.eq/m2 (GWP 100a). In addition, according to USEtox/ecotoxicity, USEtox/human toxicity-non-cancer (scenario based on primary materials), the PV cells present the highest contributions to the total impact of the module: 55% in terms of ecotoxicity and 86% concerning human toxicity/non-cancer. A comparison with literature is provided. Moreover, a separate section of the article is about factors which influence BIPVT environmental profile, discussing parameters such as the storage materials and the end-of-life management.

Payback times and multiple midpoint/endpoint impact categories about Building-Integrated Solar Thermal (BIST) collectors.

The purpose of the present article is the evaluation, by means of life cycle assessment, of a system which consists of vacuum-tube solar thermal collectors. The system is appropriate for building integration and it has been developed in France. The methods ReCiPe and USEtox have been adopted. Regarding life-cycle results, according to the scenario "without recycling" and for 30-year system lifespan, ReCiPe payback time was calculated to be 18.14 years based on France's electricity mix whereas by using Spain's electricity mix (hypothetical scenario) it was found to be 4.03 years. Recycling offers a ReCiPe-payback time reduction of 2.66 years based on France's electricity mix and 0.59 years based on Spain's electricity mix. All the studied cases show ReCiPe payback times much lower than an assumed system-lifespan of 30 years. On the basis of ReCiPe midpoint and by considering material manufacturing of the 16 collectors and the additional elements of the system (scenario "without recycling"), among glass-, aluminium-, copper- and steel-based components, the copper-based ones present the highest impact in 15 of the 18 impact categories. For instance, for Freshwater eutrophication, the copper-based elements have a score that is around 30 times higher comparing to that of the aluminium-based ones. The USEtox findings, for the material manufacturing of the 16 collectors and the supplementary elements of the system and for the scenario "without recycling", reveal that the material with the highest total score in terms of: i) human toxicity/cancer is copper (6.7E-09 CTUh), ii) human toxicity non-cancer is propylene glycol (4.0E-08 CTUh), iii) ecotoxicity is copper (2.06 CTUe). Recycling of the metals, according to USEtox, offers an impact reduction of 20-95%. A discussion about factors that influence the environmental profile of building-integrated solar systems is also provided.

Cumulative energy demand and global warming potential of a building-integrated solar thermal system with/without phase change material.

Building-integrated solar thermal (BIST) systems are a specific type of solar thermal systems which are integrated into the building and they participate in building functionality. The present article is about the life-cycle assessment of different options of a BIST system (Mediterranean climatic conditions: Ajaccio, France). The environmental profile of the studied configurations is assessed by means of CED (cumulative energy demand), GWP (global warming potential) and EPBT (energy payback time). The proposed configurations (for the collector) include: i) a system without PCM (phase change material) using only rock wool as insulation and ii) a system with PCM (myristic acid) and rock wool. Concerning life-cycle results based on CED and GWP 100a (scenario without recycling), the configuration without PCM shows 0.67 MJprim/kWh and 0.06 kg CO2.eq/kWh while the configuration with PCM presents 0.74 MJprim/kWh and 0.08 kg CO2.eq/kWh. Regarding EPBT, if the inputs for pumping/auxiliary heating are not taken into account, both configurations (with/without PCM) have almost the same EPBT (about 1.3 years). On the other hand, if the inputs for pumping/auxiliary heating are considered, EPBT is lower for the system with PCM. In addition, scenarios with recycling have been examined and the results demonstrate that recycling considerably improves the environmental profile of the studied configurations.