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Information on the scale of food waste, its sources, causes and associated environmental impacts is critical for devising food waste prevention strategies. A number of studies have focused on these issues, but there are still significant knowledge gaps, both in terms of the amount of food waste generated in various parts of the supply chain and the related impacts. In an attempt to address some of these gaps, this study focuses on food waste in the UK to estimate its quantities along the whole supply chains and to assess the resulting life cycle environmental impacts. Furthermore, the contributions of various food groups to food waste and their impacts in different life cycle stages are also quantified. The findings suggest that 13.1 Mt of food waste is generated annually in the UK across all the supply chain, leading to the greenhouse gas emissions of 27 Mt of CO2 eq./yr. The highest volume of waste is generated in the cereals (31%) and vegetables & roots subsectors (28%). However, meat and fish are the major contributors to the total life cycle environmental impacts, even though they account for only 10% of the overall food waste. Although post-consumer waste has the highest contribution, both in terms of waste quantities and environmental impacts, the contribution of other stages (primary production, food processing and distribution) is also significant. These findings emphasise the need to consider environmental impacts of food waste and engage all supply chain actors in formulating food waste reduction strategies.

The success of deploying energy and water technologies in remote communities in developing countries can be improved by considering their synergistic relationships and their social, economic and environmental implications. This paper first evaluates social implications of current energy and water supply in a prototypical remote community against five future (2030) scenarios for synergistic provision of electricity, heat for cooking and water. This is followed by an integrated assessment of the social, environmental and economic life cycle sustainability through multicriteria decision analysis. The Business-as-usual (BAU) scenario shows high life cycle health impacts but low impacts from local air pollution. The contrary is true for the Independent and Advanced Independent scenarios which assume community self-sufficiency in energy and water supply. Greater access to electricity and water in the Advanced and Advanced Independent scenarios increases the potential for human development and security of supply, but there is an increase in the risk of accidents and decrease in social acceptability of the water supply. Similarly, a transition towards clean cooking fuels away from traditional solid biomass reduces local air pollution but increases reliance on imported fuels (BAU and Advanced scenarios). The Transition scenario is socially the most sustainable option, while Independent and Advanced Independent are the best options environmentally. They also have the lowest total operating costs, but have higher capital requirements than most other scenarios. Overall, unless extreme preferences for either environmental or social aspects are adopted, the Transition and Independent scenarios emerge as the most sustainable options. This suggests that current energy and water supply to remote communities can be transitioned sustainably to a self-sufficient system that does not depend on imported resources. The scenarios developed in this work present a framework for an integrated design and evaluation of energy and water supply in remote communities with the aim of aiding stakeholders in defining sustainable transition pathways.

Offshore wind electricity is becoming an important source of renewable energy due to its global warming potential (GWP). However, the GWP can vary significantly, depending on many factors, including the capacity of the installation, distance from the shore, supporting structure andmaintenance requirements. Currently, there is a lack of life cycle assessment (LCA) studies that take these specific conditions into account. As a consequence, developers and policy makers rely on average GWP values which could lead to inaccurate estimates of the GWP and other impacts. To address this gap, this paper presents a new model for estimating the life cycle impacts of offshore wind electricity taking into account specific technical characteristics of individual installations and whole wind farms. Aimed at non-experts, the model provided freely with this paper is developed in Excel and follows the ISO 14040/44 LCA methodology. Supported by the built-in background LCA databases, it requires users to specify only a few key characteristics of an existing or proposedinstallation, thus facilitating quick and yet robust estimations of impacts. Eleven impacts can be considered, including GWP, depletion of resources, human toxicity and eco-toxicities. The application of the model is illustrated by quantifying the LCA impacts of 20 offshore wind farms (OWF) operating in the UK. The results show that the impacts vary considerably with the specific characteristics of OWF, including the age, type and size of wind turbines, their capacity and distance from the shore. For example, the GWP ranges by a factor of three (6.4-19.5 g CO2 eq./kWh) and the other impacts by a factor of 2.2-3.2. The developed model can be used by designers, developers and policy makers to customise the inputs for a specific OWF and estimate the impacts quickly and cost-efficiently, without the need for prior expertise in LCA and extensive data collection. Keywords: Energy planning; Energy modelling; Life cycle assessment; Wind electricity; Sustainable energy

Although electricity supply is still dominated by fossil fuels, it is expected that renewable sources will have a much larger contribution in the future due to the need to mitigate climate change. Therefore, this paper presents a new framework for developing Future Electricity Scenarios (FuturES) with high penetration of renewables. A multi-period linear programming model has been created for power-system expansion planning. This has been coupled with an economic dispatch model, PowerGAMA, to evaluate the technical and economic feasibility of the developed scenarios while matching supply and demand. Application of FuturES is demonstrated through the case of Chile which has ambitious plans to supply electricity using only renewable sources. Four cost-optimal scenarios have been developed for the year 2050 using FuturES: two Business as usual (BAU) and two Renewable electricity (RE) scenarios. The BAU scenarios are unconstrained in terms of the technology type and can include all 11 options considered. The RE scenarios aim to have only renewables in the mix, including storage. The results show that both BAU scenarios have a levelised cost of electricity (LCOE) lower than, or equal to, today’s costs ($72.7–77.3 vs $77.6/MWh) and include 81–90% of renewables. The RE scenarios are slightly more expensive than today’s costs ($81–87/MWh). The cumulative investment for the BAU scenarios is $123-$145 bn, compared to $147-$157 bn for the RE. The annual investment across the scenarios is estimated at $4.0 ± 0.4 bn. Both RE scenarios show sufficient flexibility in matching supply and demand, despite solar photovoltaics and wind power contributing around half of the total supply. Therefore, the FuturES framework is a powerful tool for aiding the design of cost-efficient power systems with high penetration of renewables.

Various frameworks have been developed to guide organisations in embedding circular economy principles in their strategy and operational practice. However, there is a lack of studies analysing practical implementation of circular economy thinking in the higher education sector. Higher education institutions are strategic agents in supporting sustainable development through teaching, research and social outreach activities. They also represent a source of environmental impacts due to significant resource consumption and waste generation. This paper presents the first comprehensive study showing how higher education institutions can use an action-led step-by-step approach to build a business case and implement circular economy thinking in practice. The University of Manchester is used as an illustrative example of a large higher education institution. First, a background analysis and semi-structured interviews were carried out to determine the scope of the university's current sustainability policies and the ability of the management systems to respond to circular economy challenges. This was followed by stakeholder workshops to identify gaps and opportunities for building a business case for implementation of a circular economy. Finally, a critical assessment of the outcomes was carried out to identify further research needs for implementation of a circular economy in higher education institutions. Although focused on the higher education sector, the proposed action-led approach can be used by any organisation in the service sector looking to build more circular and sustainable business models.

Consumers are the leading producers of food waste (FW) in developed countries and the majority of household FW is still embedded in general waste where it is incinerated or landfilled. There is increasing awareness in the value of collecting FW as a separate waste stream for production of compost or recovery of energy through anaerobic digestion (AD). This study focuses on AD to evaluate the life cycle environmental sustainability of recovering energy and fertilisers from household FW in the UK. The analysis is carried out for two different functional units: i) treatment of 1 tonne of FW, which is compared to incineration and landfilling; and ii) generation of 1 MWh of electricity, which is compared to other electricity generation options. The former results in net negative greenhouse gas (GHG) emissions (−39 kg CO2-eq./t) and primary energy demand (−2 GJ/t) due to the displacement of grid electricity and mineral fertilisers. AD has lower impacts than both incineration and landfilling across 15 of the 19 impacts. However, the application of digestate to land and the release of ammonia and nitrates lead to higher marine eutrophication (ME), terrestrial acidification (TA) and particulate matter formation (PMF). For the second functional unit, AD electricity emits 203 kg CO2-eq./MWh, compared to 357 kg CO2-eq./MWh for the UK grid mix. Compared to renewables, such as wind and solar, AD electricity has lower energy demand, toxicity potentials and metal depletion. However, it has higher global warming potential, ME, TA and PMF. At the UK level, treating 4.9 Mt of kerbside FW collected annually could provide 0.37% of the national electricity demand and save 190,000 t CO2-eq./yr compared to the grid electricity. The digestate produced could displace 1% of industrial nitrogen fertilisers. Although small fractions of the national demands, they represent a valuable return from a largely unutilised waste stream and help towards implementation of a circular economy.

The poultry industry generates a large quantity of litter, which consists of a mixture of manure, waste bedding and feathers, and can be used for recovery of energy. Recent studies suggest that gasification is a promising technology for an effective conversion of poultry litter to energy. This paper aims to assess the environmental impacts of generating electricity from the gasification of poultry litter in a small-scale integrated gasification combined cycle (IGCC) plant. Gasification of poultry litter has been simulated with ASPEN Plus® software and life cycle assessment has been used to determine the carbon footprint and primary energy demand of the system. The following life cycle stages have been considered: collection and storage of poultry litter, its gasification, syngas cleaning, production of electricity and co-production of ash as a fertiliser. The carbon footprint and primary energy demand of generating 1 kWh of energy by poultry litter gasification plant are estimated at 42 g CO2 eq./kWh and 0.14 MJ/kWh, respectively. Compared to electricity from fossil fuels, this system has 91%-96% smaller carbon footprint and 98%-99% lower primary energy demand. The energy payback period is estimated at 1.5 years. © 2019 The Authors. Published by Elsevier Ltd. This is an open access article under the CC BY-NC-ND license (https://creativecommons.org/licenses/by-nc-nd/4.0/)

Biofuels are being promoted as a low-carbon alternative to fossil fuels as they could help to reduce greenhouse gas (GHG) emissions and the related climate change impact from transport. However, there are also concerns that their wider deployment could lead to unintended environmental consequences. Numerous life cycle assessment (LCA) studies have considered the climate change and other environmental impacts of biofuels. However, their findings are often conflicting, with a wide variation in the estimates. Thus, the aim of this paper is to review and analyse the latest available evidence to provide a greater clarity and understanding of the environmental impacts of different liquid biofuels. It is evident from the review that the outcomes of LCA studies are highly situational and dependent on many factors, including the type of feedstock, production routes, data variations and methodological choices. Despite this, the existing evidence suggests that, if no land-use change (LUC) is involved, first-generation biofuels can—on average—have lower GHG emissions than fossil fuels, but the reductions for most feedstocks are insufficient to meet the GHG savings required by the EU Renewable Energy Directive (RED). However, second-generation biofuels have, in general, a greater potential to reduce the emissions, provided there is no LUC. Third-generation biofuels do not represent a feasible option at present state of development as their GHG emissions are higher than those from fossil fuels. As also discussed in the paper, several studies show that reductions in GHG emissions from biofuels are achieved at the expense of other impacts, such as acidification, eutrophication, water footprint and biodiversity loss. The paper also investigates the key methodological aspects and sources of uncertainty in the LCA of biofuels and provides recommendations to address these issues.

Access to clean water is one of the targets in the UN Sustainable Development Goals. However, millions of people are still without basic water services, predominantly in rural areas in developing nations. Previous studies have investigated the environmental impacts of water provision, but they mostly focused on large-scale urban systems. This paper considers for the first time the life cycle environmental impacts of different water supply options applicable to remote communities in developing countries. Focusing on the Southeast Asia-Pacific (SEAP) context, a cradle-to-grave approach is followed to estimate the impacts of locally-sourced groundwater, surface water and desalinated seawater as well as externally-sourced bottled water. The results reveal that surface water is environmentally the most sustainable alternative. Locally desalinated water, powered by diesel electricity, has two orders of magnitude higher impacts than surface water. However, externally-sourced water in plastic bottles is the worst option with 4–155 times higher impacts than desalinated water and up to three orders of magnitude higher impacts than surface water. This is largely due to the impacts related to the production of bottles. Doubling their recycling would reduce the impacts by 7–23% but bottled water would still be environmentally the least sustainable option. Although water in single-use bottles currently provides only 3% of the water supply of a representative remote community in the SEAP region considered in this study, it accounts on average for more than 50% of the total impacts from water consumption. By 2030, population increase could lead to greater reliance of remote communities on bottled water and 60–73% higher impacts of water consumption per household. Relying solely on local surface, ground and water desalinated using solar power and avoiding bottled water would reduce the impacts by 33–99% relative to the current situation. This would also improve considerably water availability and security in remote communities. The findings of this study will be of interest to national and local governments developing future policies aimed at increasing access of remote communities to clean water.

Cement production is a highly energy-intensive process, contributing 7% to the global CO2 emissions. Over 80% of the energy used in cement production is consumed by the calcination process. This paper considers a novel solar thermal technology for calcination, to investigate if it could help mitigate the climate change and other environmental impacts from cement production on a life cycle basis. The following three solar options are compared to conventional fossil-fuel calcination via life cycle assessment: a full solar system, which provides all the required thermal energy, and two hybrid systems, where the solar system provides 14% and 33% of the thermal energy, respectively. The results show that all three solar options have lower impacts than conventional calcination in 14 out of 17 categories. The full solar system is the best alternative, with major reductions in climate change (48%), fossil depletion (75%), photochemical ozone formation (92%) and terrestrial ecotoxicity (79%). Based on insolation levels in different parts of the world, the solar systems could be applied to 26% of current global cement production. This would reduce the climate change impact by 15–40%, as well as most other impacts by 14–87%, depending on the fuel mix. However, a limiting factor might be two times greater land occupation than by the conventional process. Furthermore, the solar system has higher human toxicity-cancer (102%) and metals and minerals depletion (6%) due to the construction of solar facilities. Coupling conventional calcination with carbon capture and storage (CCS) is more efficient in reducing the climate change impact (63%) than the solar system (48%) relative to conventional calcination without CCS. However, adding CCS to the solar calciner would still be a better option, decreasing the impact by 81% relative to conventional calcination without CCS. These findings will be of interest to the solar and cement industries as well as other industrial sectors using high-temperature processes.

Access to clean cooking fuels and technologies is essential for achieving the Sustainable Development Goals, particularly in developing countries, to minimise human health and environmental impacts. This paper assesses for the first time the environmental sustainability of household cooking, focusing on remote communities in developing countries in the Southeast Asia-Pacific (SEAP) region and considering both life cycle and local impacts. To guide rural development policies, the impacts of the following cooking fuels are considered: liquefied petroleum gas, kerosene, wood, charcoal, crop residues, biogas and electricity. Both the present situation and three future (2030) scenarios are evaluated on 18 life cycle impacts, as well as on local environmental and health impacts caused by cooking. The results show that electricity is the worst option in 13 out of 18 life cycle categories since it is generated from diesel in off-grid communities. Biogas from manure is the best fuel with 16 lowest life cycle impacts. Biomass fuels can have lower life cycle impacts than fossil fuels but they have high combustion emissions which lead to higher local environmental and health impacts. Future scenarios with higher biomass utilisation have up to 47 times lower life cycle impacts than at present, but 4-23% higher local impacts. Health impacts related to fuel combustion are higher in Vietnam, the Philippines, Cambodia, Laos and Myanmar compared to the other SEAP countries due to regional background pollutant concentrations and health trends. A fuel mix with liquefied petroleum gas, biogas and renewable electricity offers considerable reductions in 13 life cycle impacts compared to the present situation, while also reducing local health impacts by 78-97%. A self-sufficient fuel mix with local biomass and renewable electricity would reduce 17 out of 18 life cycle impacts, but all local impacts, including on health, would be 11-28% higher than at present. The results from this study can be used by policy makers and other stakeholders to develop policies for clean cooking in remote communities and reduce both environmental and human health impacts.

Soil salinity is among the major threats affecting the soil fertility, stability and vegetation. It can also accelerate the desertification processes, especially in arid and semi-arid regions. An accurate estimation of the global extent and distribution of the salt-affected soils and their temporal variations is pivotal to our understanding of the salinity-induced land degradation processes and to design effective remediation strategies. In this study, using legacy soil profiles data and a broad set of climatic, topographic, and remotely sensed soil surface and vegetative data, we trained ensembles of classification and regression trees to map the spatio-temporal variation of the soil salinity and sodicity (exchangeable sodium percentage) at the global scale from 1980 to 2018 at a 1 km resolution. The User’s Accuracies for soil salinity and sodicity classification were 88.05% and 84.65%, respectively. The 2018 map shows that globally ̴ 944 Mha of the lands are saline (with saturated paste electrical conductivity > 4 ds m-1), while ̴ 155 Mha can be classified as sodic soils (with sodium exchange percentage > 15%). Our findings and provided dataset show quantitatively how soil salinization is influenced by a broad array of climatic, anthropogenic and hydrologic parameters. Such information is crucial for effective water and land-use management, which is important for maintaining food security in face of future climatic uncertainties. Moreover, our results combined with the quantitative methodology developed in this study will provide us with an opportunity to delineate the role of anthropogenic activities on soil salinization. This information is useful not only for developing predictive models of primary and secondary soil salinization but also for natural resources management and policy makers.

Improving access to energy and water in remote communities is an important step towards sustainable development. However, integrated sustainability studies at the community or household scale are rare compared to industrial or national studies. Thus, this paper presents an integrated approach to the development and evaluation of energy and water supply systems in remote communities in developing countries. Termed here “synergistic generation” (“synergen”), the approach considers simultaneously electricity, heat for cooking and water supply to determine their environmental and economic sustainability on a life cycle basis. Life cycle assessment and life cycle costing are used for this purpose. Both the current situation and future scenarios to 2030 are considered for a representative remote community. The life cycle costs of the current energy and water supply are estimated at 2944 USD/household per year, most of which (91%) is due to bottled water. The latter is also the main cause of current environmental impacts (62%), followed by cooking fuels (33%) and electricity (5%). If business as usual (BAU) continues to 2030, air pollution and eutrophication could be reduced by >40% but other 14 impacts would increase by 2–63% on the current situation due to higher dependence on diesel for electricity generation and bottled water. For the same reason, BAU also has 82% higher life cycle costs (5364 USD/household∙yr) than at present. Assuming full supply self-sufficiency (Independent scenario) leads to a >12% reduction in all impact categories, except terrestrial ecotoxicity, which increases by 5% – both trends are due to utilisation of waste biomass for cooking. The life cycle costs are reduced by 92% (231 USD/household∙yr), mainly due to the phasing out of bottled water. However, capital costs are 21% higher due to the need for multiple renewable energy installations. Pursuing moderate rather than full independence of supply (Transition scenario) would reduce most impacts and costs below those of the current situation. Overall, the Transition and Independent scenarios have lower impacts than at present in almost all environmental categories as well as lower life cycle costs. These findings demonstrate the environmental and economic feasibility of energy and water independence in remote communities as well as highlighting the likely trade-offs that should be considered during the transition.

Healthcare and pharmaceutical products are used widely but their environmental impacts are still largely unknown. This paper provides an insight into the influence of product design and consumer behaviour on the environmental impacts of the use and end-of-life of some healthcare and pharmaceutical products, with the aim of identifying improvement opportunities. The influence of product design is assessed through two types of asthma inhaler: hydrofluoroalkane (HFA) and dry-powder devices. Consumer behaviour is examined by considering the use of toothpaste and consumption of nutritional drinks. The results indicate that the use and end-of-life stages contribute significantly (∼90%) to the carbon footprint of HFA inhalers, estimated at 26.9 kg CO2/100 doses. The carbon footprint of dry-powder inhalers is 10 times smaller (2.7 kg CO2/100 doses). Product design innovations to eliminate HFA propellants could save over 13 Mt CO2 eq./y globally. The use stage is also the main hotspot for most other environmental impacts across the products considered in the study. The contribution of end-of-life stage is significant for eutrophication and some toxicity-related impacts for inhalers and toothpaste. The impacts of toothpaste and nutritional drinks are highly influenced by consumer behaviour during the use stage. For example, using cold instead of warm water for teeth brushing and a tumbler instead of leaving the tap running would reduce the carbon footprint from the use of toothpaste by 57 times and water consumption by 20 times. These findings highlight that both design innovations and changes in consumer behaviour play a significant role in addressing global environmental challenges. Therefore, in addition to environmental improvements through product development and supply change management, healthcare companies should also focus on providing consumer guidance to help lower the environmental impacts of their products.

Modern lifestyles have popularised the use of food containers, also known as food savers or Tupperware. However, their environmental impacts are currently unknown. To fill this knowledge gap, this paper presents the first comprehensive assessment of the life cycle environmental sustainability of reusable plastic and glass food savers and evaluates different options for improvements, focusing on European conditions. Taking a cradle-to-grave approach, the paper considers twelve environmental impacts, including global warming potential (GWP), acidification, eutrophication, human and ecotoxicities. The results suggest that, for example, the total GWP of using both types of food saver in the European Union (EU) amounts to 653 kt CO2 eq./year, equivalent to the annual greenhouse gas emissions of Bermuda. The use stage is the main contributor to the impacts (>40%), related to the washing of containers. Glass food savers have 12%-64% higher impacts than the plastic and should have up to 3.5 times greater lifespan to match the environmental footprint of plastic containers. Three improvement scenarios have been considered at the EU level for the year 2020: low-carbon electricity mix; implementation of the EU eco-design regulation for dishwashers; and adoption of more resource-efficient hand dishwashing techniques. The results suggest that the implementation of all three improvement options would reduce the impacts by 12%-47%. The option with the greatest potential for reducing the impacts (12%-27%) is improved hand dishwashing to reduce the amount of water, energy and detergents used. Thus, policy makers and manufacturers should devise strategies to raise awareness and guide consumers in adopting these techniques with the aim of reducing the environmental impacts associated with reusable food savers used by millions of people worldwide.

The majority of shale gas studies so far have focused on environmental impacts with few considering societal aspects. This paper presents a first and most comprehensive assessment of the social impacts of shale gas production and utilisation for electricity generation, focusing on the UK context. The assessment has been carried out based on 14 indicators, addressing the following social sustainability issues: employment, health and safety, nuisance, public perceptions, local communities, infrastructure and resources. Shale gas is compared to a range of other electricity options, including other fossil fuels, nuclear and renewables. Where appropriate and possible, the social impacts are evaluated on a life cycle basis. The results suggest that extraction and utilisation of shale gas would lead to a range of benefits, including employment opportunities and financial gains by local communities. However, these are limited and countered by a number of social barriers that need to be overcome, including low public support, noise, traffic, strain on infrastructure (e.g. wastewater treatment facilities), land use conflict and availability of regulatory resources. Furthermore, shale gas does not present a notable opportunity for increasing energy security, unless its production increases significantly above current predictions. These findings can be used by policy makers, operators and other shale gas stakeholders with an interest in the social impacts of shale gas development. The results can also be useful for other countries planning to exploit their shale gas reserves.

The service sector has the potential to play an instrumental role in the shift towards circular economy due to its strategic position between manufacturers and end-users. However, there is a paucity of supporting methodologies and real-life applications to demonstrate how service-oriented companies can implement circular economy principles in daily business practice. This paper addresses this gap by analysing the potential of service-oriented companies in the information and communication technology (ICT) sector to build and implement circular economy business models. To this end, the Backcasting and Eco-design for the Circular Economy (BECE) framework is applied in an ICT firm. BECE, previously developed and demonstrated for product-oriented applications, has been developed further here for applications in the service sector. By shifting the focus from a product-oriented approach to a user-centred eco-design, the paper shows how ICT firms can identify, evaluate and prioritise sustainable business model innovations for circular economy. The two most promising business model innovations are explored strategically with the aim of designing circular economy models consistent with the company's priorities of customer satisfaction and profitability. The findings suggest that ICT companies may be able to support the deployment of a circular economy in the service-oriented technology sector. Importantly, micro and small organisations can play a fundamental role if provided with macro-level support to overcome company-level barriers. Finally, the BECE framework is shown to be a valuable resource to explore, analyse and guide the implementation of circular economy opportunities in service-oriented organisations. Further research to verify the application of the findings to other service-oriented organisations is recommended.

The difficulties in climate change negotiations together with the recent withdrawal of the U.S. from the Paris Agreement call for new cooperative mechanisms to enable a resilient international response. In this study we propose an approach to aid such negotiations based on quantifying the benefits of interregional cooperation and distributing them among the participants in a fair manner. Our approach is underpinned by advanced optimisation techniques that automate the screening of millions of alternatives for differing levels of cooperation, ultimately identifying the most cost-effective solutions for meeting emission targets. We apply this approach to the Clean Power Plan, a related act in the U.S. aiming at curbing carbon emissions from electricity generation, but also being withdrawn. We find that, with only half of the states cooperating, the cost of electricity generation could be reduced by US$41 billion per year, while simultaneously cutting carbon emissions by 68% below 2012 levels. These win–win scenarios are attained by sharing the emission targets and trading electricity among the states, which allows exploiting regional advantages. Fair sharing of dividends may be used as a key driver to spur cooperation since the global action to mitigate climate change becomes beneficial for all participants. Even if global cooperation remains elusive, it is worth trying since the mere cooperation of a few states leads to significant benefits for both the U.S. economy and the climate. These findings call on the U.S. to reconsider its withdrawal but also boost individual states to take initiative even in the absence of federal action., Energy & Environmental Science, 11 (3), ISSN:1754-5692, ISSN:1754-5706

This paper presents for the first time a life cycle environmental, economic and social sustainability assessment of future electricity scenarios for Turkey up to 2050. Fourteen scenarios have been developed and assessed for 19 sustainability indicators, using multi-criteria decision analysis (MCDA) to help identify the most sustainable scenarios. The fossil fuel dominated scenarios are environmentally the least sustainable for seven out of 11 impacts, including the global warming potential (GWP) which increases up to four times on today’s impact. Opting for renewable-intensive pathways would halve the current GWP and reduce the use of fossil fuels by three times; however, the depletion of elements would increase 70-fold and investment costs 10-fold. MCDA shows that renewable and nuclear intensive scenarios outperform those dominated by fossil fuels, except for the very high preference for the economic criteria. However, their poor environmental and social performances makes them least sustainable overall. The renewable-nuclear intensive scenarios are the most sustainable options with respect to most of the environmental, economic and social impacts considered. Reducing the share of fossil fuels in the electricity mix would not only reduce significantly the environmental impacts, but also the costs, injuries and fatalities, while also improving energy security.

Many higher education institutions have started to develop academic curricula, research capacity and outreach activities related to circular economy. However, little is known yet on how to apply circular economy thinking to sustainable campus management. In an attempt to address this gap, this paper proposes a methodological framework and guidance to help universities develop a circular economy strategy aimed at improving resource efficiency and environmental sustainability of their campus operations. The approach is compatible with sustainability management frameworks as it follows the well-known iterative process of planning, doing, checking and improving. The framework involves three main steps: analysis of current situation with respect to circular economy within the organisation; stakeholder engagement to get a buy-in and inform the development of a circular economy strategy; and implementation of the strategy following the guidelines provided within the framework. Application of the framework is illustrated through a case of the University of Manchester, demonstrating how circular economy principles can be used to benchmark existing sustainability policies and action plans. The paper also shows how engaging key stakeholders can be used to identify challenges and opportunities for embedding circular economy thinking into the university's sustainability management systems. The proposed framework and the guidelines for implementation of circular economy thinking are generic and can be applied by any institution across the higher education sector.

Thin-film technologies have been part of the rapidly-expanding solar photovoltaics (PV) market for many years, led by cadmium-telluride (CdTe) and copper‑indium‑gallium-selenide (CIGS). However, their environmental impacts remain largely unknown, particularly considering state-of-the-art CIGS manufacturing techniques. This study estimates the life cycle environmental impacts of CIGS PV installations in the UK and Spain, including balance-of-system components, using real manufacturing data. It also analyses newly-developed CIGS, replacing the cadmium sulphide (CdS) buffer layer with zinc oxysulphide (Zn(O,S)) via atomic layer deposition (ALD). The results show that UK installations have 72% higher impacts than those in Spain, including climate change (25.1 vs 14.6 g CO 2 eq./kWh). The inverter and electrical components are the main contributors (46% on average), followed by the PV modules (41%). In comparison to CdTe, mono-Si and multi-Si PV, CIGS has 6%–90% lower impacts in 16 out of 18 categories, including climate change (16%–50% lower). However, metal depletion is five times higher, and land use 12%–31% greater. The replacement of CdS has a small but positive effect, demonstrating that cadmium can be eliminated from the CIGS life cycle without environmental penalties. These results will be of interest to PV manufacturers and policy makers, indicating improvement opportunities and areas for policy intervention.

This study uses life cycle assessment to evaluate the environmental impacts of electricity generated from fossil fuels in Chile over a ten–year period, from 2004 to 2014. The focus on fossil fuels is highly relevant for Chile because around 60% of electricity currently comes from natural gas, coal and oil. The impacts are first considered at the level of individual technologies, followed by the evaluation of the fossil-fuel electricity mix over the period. The study has been carried out using detailed primary data for 94 operating plants. Considering individual technologies, coal power has the worst performance for eight out of 11 impacts, with eutrophication, freshwater and marine ecotoxicity being between ten and 240 times greater than for gas. However, oil is worse than coal for photochemical oxidants (31%) and depletion of elements and ozone layer (four and eight times, respectively). Between 2004 and 2014, the annual environmental impacts doubled, while electricity generation rose only by 55%. The only exception to this is ozone depletion which fell by around 4%. The highest impacts occurred in 2014 mainly because of the high contribution of coal power. Therefore, the environmental performance of fossil-based electricity in Chile has worsened over time due to the growing share of coal power, coupled with the increasing electricity demand. Consequently, policy should aim to increase the efficiency of power plants, avoid the use of petroleum coke, improve emissions control and replace coal and oil with gas power as soon as possible.

This study aims to develop a novel method to synthesise site-wide heat recovery, distribution, cogeneration systems with optimum operating conditions of the steam mains. Previous approaches have simplified the problem to the extent that many important practical issues have been neglected and restricted the scope of the options included. The proposed methodology uses a combination of total site analysis and mathematical programming for a holistic approach to the steam system, which accounts for interactions between site utility system and processes. The optimisation problem involves the selection of more realistic operating conditions of the steam mains (superheating and pressure). The model will also account for water preheating, and superheating and desuperheating for process steam generation and use. Deaerators and let-down stations are also included in the analysis. The application of this methodology to a case study yielded a 7.6 % reduction in total energy requirement, compared to conventional utility system design method. The proposed approach addresses severe shortcomings in previous research on this topic and provides a foundation for future work to explore the next generation of sustainable utility systems.

This work aims to assess the environmental and economic sustainability of poultry litter gasification for heat and electricity generation. The results are compared with gasification of two other biomass feedstocks (Miscanthus and waste wood) and energy from fossil fuels. The findings suggest that poultry litter gasification can lead to significant reductions in 14 out of 16 impacts considered in the study in comparison with fossil-fuel alternatives. Compared to combined heat and power (CHP) from natural gas, most impacts from gasification of the litter are lower by more than 90%, including global warming potential. However, human toxicity and depletion of minerals are 25% and three times higher, respectively. Energy from poultry litter also has lower impacts than from waste woodchips and Miscanthus across all the categories, except for acidification. Owing to high capital costs, the unsubsidised cost of generating heat and electricity from poultry litter is similar to that of natural gas CHP but significantly cheaper than from other fossil-fuel alternatives. However, with the current subsidies in the UK, the payback time for poultry litter gasification is 13.5 years. It is estimated that 4.55 Mt of poultry litter is currently available in the UK, 2.73 Mt of which is suitable for conversion to energy. If this waste is utilised in gasification plants, it could potentially provide 0.6% of electricity and heat in the UK and save 1.7 Mt of GHG per year, equivalent to around 0.4% of UK's GHG emissions. However, the successful uptake of this technology will depend on a future reduction in capital costs.

Biscuits are a major product category in the global confectionary sector. Despite this, their environmental impacts are poorly characterised. Therefore, this paper sets out to evaluate the life cycle environmental sustainability of the following widely-consumed types of biscuit, both at the product and sectoral levels: crackers, low fat/sugar, semi-sweet, chocolate-coated and sandwich biscuits with chocolate or vanilla cream. The results obtained through life cycle assessment demonstrate that, in addition to being healthier, low fat/sugar biscuits have the lowest impacts across most of the 18 categories considered. Chocolate-coated biscuits are environmentally the least sustainable. The most significant life cycle stage for all types is the raw materials production, causing 41%–61% of the total impacts, with flour, sugar and palm oil being the key hotspots. Replacing palm with rapeseed oil would improve five impacts but worsen another five, including a 34% increase in agricultural land occupation and marine eutrophication. Therefore, the cultivation and production of palm oil, rather than its replacement, should be targeted for improvements. The second most crucial stage is manufacturing, contributing up to 54% of the impacts, followed by transport with up to 35%. Reducing energy consumption by 25% in manufacturing would reduce primary energy demand by 8%–12%, fossil fuel depletion by 9%–12% and global warming potential by 6%–9%. The latter would increase by 55% if land use change related to cocoa was involved, despite a very small amount of cocoa in the biscuits (∼1%). The analysis at a sectoral level in the UK, the leading consumer of biscuits in Europe, reveals that biscuits contribute 7.4% of primary energy demand and 0.5% of greenhouse gas emissions of the whole UK food sector. These results can help guide manufacturers in mitigating the hotspots in the supply chain and consumers in selecting environmentally more sustainable biscuits.

The confectionary and frozen desserts sectors are important parts of the food industry but have received relatively little attention from a life cycle cost perspective. Thus, the purpose of the current study is to evaluate the life cycle costs (LCC) and value added (VA) in these sectors in the UK, focusing on four major product categories: biscuits, cakes (ambient and frozen), chocolates and ice cream. In total, 18 products are considered along their life cycles, including the raw materials, manufacturing, packaging, distribution, retail, consumption and waste management stages. The results suggest that cakes have the highest LCC (£1.52–2.64/kg) and the biscuits the lowest (£0.72–0.91/kg). The LCC of chocolates and ice cream fall within a similar range to each other (£1.16–1.46/kg and £1.03–1.30/kg, respectively). Divergent trends are noted between LCC and VA: for instance, ‘premium’ ice creams have only 18% higher costs than their ‘regular’ counterparts, but a four-fold higher VA. For all the products, raw materials contribute most to the costs (43%–95%), followed by packaging (1%–29%) and manufacturing (1%–14%). The annual LCC at the sectoral level are estimated at £3.455 billion, to which biscuits contribute 42%. The share of chocolates and cakes is 24% and 19%, respectively, with ice cream contributing the remaining 15%. By contrast, chocolates contribute more than 50% of the total sectoral VA, which is five-fold higher than that of ice cream. The study also demonstrates how LCC can be used to evaluate the eco-efficiency of products and sectors. With respect to global warming potential, whole cakes are the most eco-efficient and vanilla regular ice cream the least efficient products. Overall, the confectionary sector is nearly 70% more eco-efficient than the frozen desserts sector. These results can be used for benchmarking and to drive innovation towards more economically-sustainable and eco-efficient confectionary and frozen desserts supply chains.

Agricultural wastes are readily available in farming communities and can be utilised for off-grid electrification as an alternative to diesel generators. This work evaluates for the first time the life cycle environmental sustainability of these small-scale systems in the context of Southeast Asia. Rice and coconut residues are considered for direct combustion and gasification, and livestock manure for anaerobic digestion. Overall, anaerobic digestion is the best option for 14 out of 18 impacts estimated through life cycle assessment. The results also suggest that gasification has up to 12 times lower impacts per kWh than combustion, except for resource depletion. Combustion and gasification have 85% to two times lower impacts than diesel generators, except for eutrophication, ecotoxicity and human toxicity. Depending on the feedstock, global warming potential of anaerobic digestion ranges from being 170% lower to 41% higher than that of the diesel generator. Overall, providing power from residual biomass in small agricultural communities would reduce environmental impacts significantly while improving waste management practices.

This study considers the life cycle impacts of land use on biodiversity and ecosystem services associated with the production of a ubiquitous food type: breakfast cereals. For biodiversity, the impacts on five taxonomic groups have been assessed: mammals, birds, vascular plants, amphibians and reptiles. For ecosystem services, the potential loss in the following ecosystem services of soil has been considered: biotic production, erosion resistance, groundwater regeneration, infiltration and physicochemical filtration. The findings indicate that the main hotspot for the biodiversity loss is cocoa cultivation for all taxonomic groups, with a contribution of 27–67%. Cocoa is also a major contributor (35%) to the loss of biotic production, while rice is the largest contributor to erosion (34%), reduction in groundwater replenishment (43%) and physiochemical filtration (23%). Corn is the main cause of the infiltration reduction, accounting for 44% of the impact. Unlike the biodiversity impacts, which are almost entirely caused by agricultural activities, non-agricultural land use occurring in other life cycle stages (transport, packaging and manufacturing), has significant contribution to the reductions in groundwater replenishment and infiltration. The impacts on ecosystem services are almost entirely driven by land occupation, while the biodiversity impacts are caused by both land use change and occupation. The identification of cocoa as the main hotspot is unexpected as it is used only in very small quantities (

Convenience is one of the main determinants of modern society where products, such as ready-made meals, play a key role. However, the continuing growth of this market has raised environmental concerns, which have not been well studied yet. This paper evaluates life cycle environmental impacts of meals consumed in the UK, the second largest consumer of ready-made meals in the world, after the US. Thirteen representative ready-made meals are evaluated in the British, Italian, Chinese and Indian cuisines, considering variations in recipes found on the market, as well as different meat replacement options. The results suggest that environmentally the most sustainable meal option is pork roast dinner while the worst alternatives are spaghetti Bolognese, cottage pie, lamb masala curry and lasagne. For example, the global warming potential of pork roast is 2.1 kg CO2 eq. and that of lasagne 5 kg CO2 eq. The ingredients contribute >50% to the impacts, followed by the distribution (~14%) and manufacturing (~12%) stages. Using seitan or soy granules as meat replacements improves five out of 11 impacts considered, including global warming potential, by up to 27%; the other impacts are largely unaffected. However, if tofu is used, four impacts are improved while four others are worsened. The annual consumption of ready-made meals in the UK accounts for GHG emissions of 12.89 Mt. CO2 eq., equivalent to emissions of a whole country, such as Jamaica. This contributes 15% to the emissions from the UK food and drink sector. It also represents 8% and 15% of the personal carbon budgets for food related to climate targets of 2 °C and 1.5 °C, respectively. The results of the study will be of interest to both food manufacturers and consumers, showing how their choices affect the environmental sustainability of this fast-growing sector.

The use of biomass for production of chemicals is gaining interest because of its potential to contribute towards a reduction in greenhouse gas emissions and other environmental benefits linked to the substitution of fossil resources. But, conversely to biofuels, studies focusing on environmental impacts of biomass-derived chemicals are scarce. This paper uses life cycle assessment to evaluate the environmental sustainability of bio-ethylene from poplar produced by the following three thermo-chemical routes: direct and indirect dehydration of ethanol and production of olefins via dimethyl ether. The indirect route is the best option for most impact categories for all three allocation methods considered: system expansion, economic and energy basis. However, the dimethyl ether-to-olefins route has the lowest global warming potential. In comparison to ethylene produced bio-chemically from sugar beet, the thermo-chemical indirect route has lower impacts for all categories except human, terrestrial and freshwater toxicities. All three thermo-chemical alternatives show a significant reduction in global warming potential (up to 105% in the case of dimethyl ether-to-olefins) and depletion of fossil fuels when compared to conventional ethylene production from fossil fuels. However, the results also suggest that bioethylene produced by any of the three thermo-chemical routes would lead to a significant increase in most other impact categories relative to fossil fuels. Therefore, while trying to reduce greenhouse gas emissions, the overall environmental sustainability of bio-ethylene suffers from the increase in other environmental impacts. Universidad de Sevilla VPPI-US

Growing uncertainty in the future availability of freshwater sources has led to an increase in installations for desalination of seawater. Reverse osmosis (RO), currently the most widely adopted technique, has caused environmental concerns over the high associated greenhouse gas emissions and generation of large amounts of chemicals-containing brine. Significant consumption of electricity for RO desalination is an additional challenge, particularly in remote locations. In this review, forward osmosis (FO), membrane distillation (MD) and capacitive deionisation (CDI) are assessed as potential substitute technologies and the major recent advancements in each field are discussed. These emerging technologies offer significant advantages over RO, such as higher salt rejection (CDI, MD), higher recovery of water (MD), fewer pre-treatment stages (MD, FO) and the ability to use low-grade energy (MD, FO). In their current state, stand-alone technologies cannot compete with RO until certain challenges are addressed, including pore-wetting (MD) and high energy consumption (MD, CDI, FO). Hybrid systems that combine RO and emerging technologies may be useful for feed waters that cannot be treated by RO alone and their benefits may be able to offset the increase in capital costs. These and other aspects, such as operational stability should be considered in larger-scale, long-term studies.

This paper applies a life cycle approach to evaluate for the first time the environmental impacts of renewable electricity in Turkey. There are 305 power plants utilising hydro, wind and geothermal resources, all of which are considered in the study. The results indicate that the impacts from large reservoir hydropower are lower than for the small reservoir (by 45%–72%) and run-of-river hydropower (by 74%–84%). The exceptions are the global warming potential (GWP) and summer smog which are two times and 45% higher for large than small reservoir, respectively. Onshore wind is the worst option overall, with nine out of 11 impacts higher than for hydropower and geothermal. However, its GWP is 9 times and 11% lower than for geothermal and large reservoir, respectively. Acidification from geothermal is 281 times higher than for wind power. Geothermal is the best option for six impacts. Large reservoir has the lowest depletion of elements and fossil resources as well as acidification. Small reservoir and run-of-river plants are the best and geothermal the worst options for the GWP. The majority of the annual impacts from the renewable electricity mix are from hydropower with the exception of acidification which is largely from geothermal electricity.

Purpose Global beer consumption is growing steadily and has recently reached 187.37 billion litres per year. The UK ranked 8th in the world, with 4.5 billion litres of beer produced annually. This paper considers life cycle environmental impacts and costs of beer production and consumption in the UK which are currently unknown. The analysis is carried out for two functional units: (i) production and consumption of 1 l of beer at home and (ii) annual production and consumption of beer in the UK. The system boundary is from cradle to grave.

This paper presents for the first time the life cycle environmental impacts of electricity generation from fossil fuel power plants in Turkey which supply three quarters of national demand. There are 16 lignite, eight hard coal and 187 gas power plants in Turkey, all of which are considered in the study. The results suggest that electricity generation from gas has the lowest impacts for 10 out of 11 impacts considered. However, its ozone layer depletion is 48 times higher than for lignite and 12 times greater than for hard coal electricity. Lignite is the worst option overall, with eight impacts higher than for hard coal, ranging from 11% higher fossil fuel depletion to six times greater fresh water ecotoxicity. Conversely, its depletion of elements and ozone layer are four times lower than for hard coal; global warming is 6% lower. Most impacts are mainly caused by the operation of power plants and transportation of imported fuels. Annually, electricity generation from fossil fuels emits 109 Mt CO2-eq. and depletes 1660 PJ of primary fossil energy. These and the majority of other impacts are from lignite and hard coal power, despite the gas plants generating almost three and five times more electricity, respectively. Therefore, reducing the share of lignite and hard coal power and expanding the contribution of natural gas would lead to significant reductions of environmental impacts from the electricity sector in Turkey, including greenhouse gas emissions; however, ozone layer depletion would increase substantially.

Small-scale off-grid renewable energy systems are being increasingly used for rural electrification, commonly as stand-alone home systems or community micro-grids. With the variety of technologies and configurations available, it is not clear which options are sustainable for remote communities. This study investigates the life cycle environmental sustainability of both home and community installations, designed as part of this work, which utilise diesel, solar, and wind resources coupled with battery storage. A total of 21 system configurations (six home systems and 15 micro-grids) have been designed and optimised for a prototypical rural community in the Philippines, considering both stand-alone and hybrid systems. Life cycle assessment (LCA) considering 18 potential impact categories has been carried out to compare the environmental impacts associated with electricity production of each option. At the household level, hybrid solar photovoltaics (PV)-wind systems with storage have 17–40% lower impacts than the equivalent stand-alone installations per kWh generated. Batteries are a major environmental hotspot, causing up to 88% of the life cycle impacts of a home energy system. Among the community micro-grid options, the PV-wind-lead acid battery hybrid system has the lowest impacts in many categories, including climate change, ozone depletion, and acidification. Comparing equivalent architectures for single-household and community-scale installations, PV systems are environmentally more sustainable if installed individually in households, while larger turbines in community micro-grids are environmentally better for wind utilisation. The results suggest that a household-scale PV system integrated within a micro-grid with community-scale wind turbines and Li-ion batteries is environmentally the most sustainable configuration.

Hydrogen could be used as a ‘cleaner’ cooking fuel, particularly in communities that rely on biomass and fossil fuels, to reduce local pollution and related health effects. However, hydrogen must be produced using sustainable feedstocks and energy sources to ensure that local impacts are not reduced at the expense of other impacts generated elsewhere in the life cycle. To this end, this paper evaluates life cycle environmental impacts of renewable hydrogen produced in a proton-exchange membrane electrolyser using solar energy. The aim of the study is to find out if hydrogen produced in this system and used as a cooking fuel is environmentally sustainable in comparison with conventional cooking fuels typically used in developing countries, such as liquefied petroleum gas (LPG), charcoal and firewood. The results suggest that hydrogen would reduce the climate change impact by 2.5e14 times to 0.04 kg CO2 eq./MJ compared to firewood (0.10 kg CO2 eq./MJ) and LPG (0.57 kg CO2 eq./MJ). Some other impacts would also be lower by 6%e35 times, including depletion of fossil fuels, summer smog and health effects from emissions of particulates, both locally and across the rest of the life cycle. However, some other impacts would increase by 6%e6.7 times, such as depletion of metals and freshwater and marine ecotoxicity. These are mainly due to the solar photovoltaic panels used to generate power for the electrolyser. In terms of the local impacts, the study suggests that hydrogen would reduce local pollution and related health impacts by 8%e35 times. However, LPG is still environmentally a better option than hydrogen for most of the impacts, both at the point of use and on a life cycle basis UK Research Councils (EP/K011820/1)

Solar water heating (SWH) systems could help reduce environmental impacts from energy use but their performance and impacts depend on the climate. This paper considers how these vary for residential SWH across four different climatic regions in Turkey, ranging from hot to cold climates. Life cycle assessment was used for these purposes. The results suggest that in the hotter regions, the impacts of SWH are 1.5–2 times lower than those of natural gas boilers. A similar trend was observed in the two colder regions except for acidification, which was four times higher than that of the boiler. The raw materials and electricity required for the manufacturing of the systems were found to be the most important contributors to the impacts. Recycling the major components instead of landfilling reduced human toxicity potential by 50% but had only a small effect (5%) on the other impacts. The impacts were highly sensitive to the type of material used for the construction of the hot storage tank, but were not affected by transport and end-of life recycling. The only exception to the latter is human toxicity potential which decreased significantly with greater recycling. Extrapolating the results at the national level showed that SWH systems could reduce the annual greenhouse gas emissions in Turkey by 790 kt CO2-eq. and would save the economy $162.5 million per year through the avoided imports of natural gas. All other impacts would also be reduced significantly (3–32 times), except for acidification which would double. Therefore, SWH systems should be deployed more extensively in Turkey but government incentives may be needed to stimulate the uptake.

The UK is in the early stages of developing a shale gas industry and to date six test wells have been drilled but none yet exploited commercially. Some argue that shale gas could reduce energy prices and improve national energy security. However, the costs of bringing commercial-size wells into operation are uncertain and the impact shale gas could have on the UK energy market is currently unknown. Therefore, this paper evaluates the economic viability of developing a UK shale gas industry and the impacts it could have on the UK gas and electricity markets and consumer energy bills up to 2030. The estimated life cycle (levelised) costs of shale gas production range from 0.47 to 56.74 pence/MJ (0.61–73 US$ cents/MJ), with an average value of 4.64 pence/MJ. The break-even price at which shale gas can be sold varies between 0.95 and 114.44 pence/MJ, averaging at 9.47 pence/MJ, depending on the volume of gas produced by a shale gas well. The latter is two times higher than imported liquefied natural gas, around 30% more expensive than UK natural gas and three times greater than the price of US shale gas. Electricity from shale gas is on average 17% more expensive than from domestic conventional gas but still more competitive than most other electricity options, including coal and renewables. However, the impact of shale gas on the energy market would be limited across the expected range of shale gas penetration into the gas and electricity mixes, suggesting that it would have little effect on energy prices. This is reflected in an almost negligible impact on consumer energy bills. The potential of shale gas to boost the UK economy is also limited, contributing 0.017–0.033% to the GDP. This is an order of magnitude lower than the contribution of US shale gas to its GDP (0.2%), indicating that the economic success of shale gas in the US may not be replicated in the UK. These findings will be of interest to shale gas developers and policy makers not only in the UK but in other countries considering exploitation of shale gas resources.

Around 40% of electricity in Chile is supplied by renewables and the rest by fossil fuels. Despite the growing electricity demand in the country, its environmental impacts are as yet unknown. To address this gap, the current study presents the first comprehensive assessment of the life cycle environmental sustainability of electricity generation in Chile. Both the individual sources and the electricity mix over the past 10 years are considered. The following sources present in the electricity mix are evaluated: coal, oil, natural gas, biogas, biomass, wind, solar photovoltaics (PV) and hydropower. In total, 10 electricity technologies and 174 power plants installed across the country have been considered. Eleven environmental impacts have been estimated, including global warming, human toxicity, ecotoxicities, as well as resource and ozone layer depletion. The results reveal that hydropower is environmentally the most sustainable option across the impacts, followed by onshore wind and biogas. Electricity from natural gas has 10%–84% lower impacts than biomass for seven categories. It is also 13%–98% better than solar PV for six impacts and 17%–66% than wind for four categories. Solar PV has the highest abiotic depletion potential due to the use of scarce elements in the manufacture of panels. While electricity generation has grown by 44% in the past 10 years, all the impacts except ozone layer depletion have increased by 1.6–2.7 times. In the short term, environmental regulations should be tightened to improve the emissions control from coal and biomass plants. In the medium term, the contribution of renewables should be ramped up, primarily increasing the hydro, wind and biogas capacity. Coal and oil should be phased out, using natural gas as a transitional fuel to help the stability of the grid with the increasing contribution of intermittent renewables.

The main objective of the SOLPART H2020 project is to develop, at a pilot scale (30-50 kW), a high temperature (800-1000°C) 24h/day solar process suitable for particle treatment in energy intensive non-metallic minerals’ industries. Calcium carbonate decomposition (Calcination reaction: CaCO3= CaO + CO2) is the most representative and most endothermal reaction in this type of application of solar process heat for industry. This paper presents the context, the particle to be treated, the reaction thermodynamics and kinetics, the mass and energy balances and the solar reactor technology currently under development.

Integrated organic farming could help reduce greenhouse gas (GHG) emissions and other environmental impacts from agriculture but studies of such practices are scarce, particularly those considering farms as whole systems and taking into account rotation cycles. To address this knowledge gap, this study considers life cycle GHG emissions and the related global warming potential (GWP) of a large integrated organic farm in the UK. The farm produces arable crops (wheat, oats, barley, beans and rye), silage and straw, livestock (dairy and beef cows, sheep/lambs and pigs) and related meat products as well as milk and wool. To ensure that the variations in the emissions with crop rotation are taken into account, the study covers a seven-year rotation cycle. The results suggest that the annual GWP of the whole farming system varies from 1816 to 2372 t CO2e over the rotation period, averaging 2118 t CO2e/yr or 2.65 t CO2e/ha. Dairy and beef cattle are the main contributors, causing 45% and 39% of GWP, respectively; this is mainly due to emissions of methane from enteric fermentation and nitrous oxide from manure. Crop cultivation adds a further 10% to the impact, while the contribution of sheep and pig husbandry is relatively small (6% and 2e, respectively. By comparison, GWP from pig meat ranges from 5.6 to 8.5 kg CO2e/kg, largely caused by feed concentrate. The impact from milk production is estimated at 1.02–1.21 kg CO2e/l, mostly related to methane emissions from enteric fermentation. The GWP from wool ranges from 20.8–30.9 kg CO2e/kg. Among the crops, beans have the highest average impact (692 g CO2e/kg) and rye the lowest (157 g CO2e/kg). The hotspots for the crops are emissions of nitrous oxide from manure application to land and use of diesel in farm machinery. A sensitivity analysis shows that the assumptions for allocating N2O emissions over the rotation cycle have a significant effect on the results. Options for reducing GHG emissions include intercropping, optimisation of feed composition and anaerobic digestion of waste.

This paper studies life cycle environmental impacts and costs of the household cooking sector in Nigeria from 2003 to 2030. Five scenarios are considered: business as usual, dominated by fuel wood stoves, low penetration of improved fuel wood and solar stoves, as planned by the government, high penetration of these stoves, increased use of fossil fuel stoves, and increased use of electric stoves. If business as usual (BAU) continues, the environmental impacts would increase by up to four times and costs by up to five times, mainly because of high fuel wood consumption. Implementing the government’s plan to introduce improved fuel wood and solar stoves would yield no environmental advantages, as the proposed number of stoves is too low. A higher number of the advanced stoves would lead to significant improvements in some impacts but would worsen others so that some trade-offs are needed. From the economic perspective, the scenario with a high use of advanced stoves has the lowest total costs but its capital costs are three times higher than for BAU. The government should prioritise the introduction of advanced stoves to reduce health impact from indoor pollution and reduce pressures on biomass resources, however, this may require subsidies. Fossil fuel and electric stoves would also help to preserve biomass and reduce health impacts from indoor pollution but would lead to an increase in greenhouse gas emissions and depletion of fossil resources.

A rapid increase in household solar PV uptake has caused concerns regarding intermittent exports of electricity to the grid and related balancing problems. A microgeneration system combining solar PV, combined heat and power plant (CHP) and battery storage could potentially mitigate these problems whilst improving household energy self-sufficiency. This research examines if this could also lead to lower environmental impacts compared to conventional supply of electricity and heat. Life cycle assessment has been carried out for these purposes simulating daily and seasonal energy demand of different household types. The results suggest that the impacts are reduced by 35–100% compared to electricity from the grid and heat from gas boilers. The exception is depletion of elements which is 42 times higher owing to the antimony used for battery manufacture. There is a large variation in impacts with household energy demand, with higher consumption resulting in a far greater reduction in impacts compared to the conventional supply. CHP inefficiency caused by user maloperation can decrease the environmental benefits of the system significantly; for example, the global warming potential increases by 17%. This highlights the need for consumer information and training to ensure maximum environmental benefits of microgeneration. Appropriate battery sizing is essential with the 10–20 kWh batteries providing greatest environmental benefits. However, any reduction in impacts from battery storage is heavily dependent on the assumptions for system credits for electricity export to the grid. Effective management of the battery operation is also required to maximise the battery lifetime: a reduction from 10 to five years increases depletion of elements by 45% and acidification by 32%. Increasing the recycling of metals from 0% to 100% reduces the impacts from 46% to 179%. If 90% of antimony is recycled, the depletion of elements is reduced by three times compared to the use of virgin antimony. However, this impact is still 12 times higher than for the conventional system owing to the use of other metals in the system.

Utilising CO2 as a feedstock for chemicals and fuels could help mitigate climate change and reduce dependence on fossil fuels. For this reason, there is an increasing world-wide interest in carbon capture and utilisation (CCU). As part of a broader project to identify key technical advances required for sustainable CCU, this work considers different process designs, each at a high level of technology readiness and suitable for large-scale conversion of CO2 into liquid hydrocarbon fuels, using biogas from sewage sludge as a source of CO2. The main objective of the paper is to estimate fuel production yields and costs of different CCU process configurations in order to establish whether the production of hydrocarbon fuels from commercially proven technologies is economically viable. Four process concepts are examined, developed and modelled using the process simulation software Aspen Plus® to determine raw materials, energy and utility requirements. Three design cases are based on typical biogas applications: (1) biogas upgrading using a monoethanolamine (MEA) unit to remove CO2, (2) combustion of raw biogas in a combined heat and power (CHP) plant and (3) combustion of upgraded biogas in a CHP plant which represents a combination of the first two options. The fourth case examines a post-combustion CO2 capture and utilisation system where the CO2 removal unit is placed right after the CHP plant to remove the excess air with the aim of improving the energy efficiency of the plant. All four concepts include conversion of CO2 to CO via a reverse water-gas-shift reaction process and subsequent conversion to diesel and gasoline via Fischer–Tropsch synthesis. The studied CCU options are compared in terms of liquid fuel yields, energy requirements, energy efficiencies, capital investment and production costs. The overall plant energy efficiency and production costs range from 12–17% and £15.8–29.6 per litre of liquid fuels, respectively. A sensitivity analysis is also carried out to examine the effect of different economic and technical parameters on the production costs of liquid fuels. The results indicate that the production of liquid hydrocarbon fuels using the existing CCU technology is not economically feasible mainly because of the low CO2 separation and conversion efficiencies as well as the high energy requirements. Therefore, future research in this area should aim at developing novel CCU technologies which should primarily focus on optimising the CO2 conversion rate and minimising the energy consumption of the plant.

Exploitation of shale gas in the UK is at a very early stage, but with the latest estimates suggesting potential resources of 3.8 × 10 13 cubic metres – enough to supply the UK for next 470 years – it is viewed by many as an exciting economic prospect. However, its environmental impacts are currently unknown. This is the focus of this paper which estimates for the first time the life cycle impacts of UK shale gas, assuming its use for electricity generation. Shale gas is compared to fossil-fuel alternatives (conventional gas and coal) and low-carbon options (nuclear, offshore wind and solar photovoltaics). The results suggest that the impacts range widely, depending on the assumptions. For example, the global warming potential (GWP100) of electricity from shale gas ranges from 412 to 1102 g CO 2 -eq./kWh with a central estimate of 462 g. The central estimates suggest that shale gas is comparable or superior to conventional gas and low-carbon technologies for depletion of abiotic resources, eutrophication, and freshwater, marine and human toxicities. Conversely, it has a higher potential for creation of photochemical oxidants (smog) and terrestrial toxicity than any other option considered. For acidification, shale gas is a better option than coal power but an order of magnitude worse than the other options. The impact on ozone layer depletion is within the range found for conventional gas, but nuclear and wind power are better options still. The results of this research highlight the need for tight regulation and further analysis once typical UK values of key parameters for shale gas are established, including its composition, recovery per well, fugitive emissions and disposal of drilling waste.

Decarbonising the UK electricity mix is vital to achieving the national target of 80% reduction of greenhouse gas (GHG) emissions by 2050, relative to a 1990 baseline. Much work so far has focused only on costs and GHG emissions ignoring other sustainability issues. This paper goes beyond to assess the life cycle sustainability of different electricity scenarios for the UK, extending to 2070. The scenarios include the main technologies relevant to the UK: nuclear, gas, coal with and without carbon capture and storage (CCS), wind, solar photovoltaics and biomass. Three levels of decarbonisation are considered and the implications are assessed for techno-economic, environmental and social impacts on a life cycle basis. The results show that decarbonisation is likely to increase electricity costs despite anticipated future cost reductions for immature technologies. Conversely, sensitivity to volatile fuel prices decreases by two-thirds in all the scenarios with low-carbon technologies. To meet the GHG emission targets, coal CCS can only play a limited role, contributing 10% to the electricity mix at most; the use of CCS also increases other sustainability impacts compared to today, including worker injuries, large accident fatalities, depletion of fossil fuels and long-term waste storage. This calls into question the case for investing in coal CCS. A very low-carbon mix with nuclear and renewables provides the best overall environmental performance, but some impacts increase, such as terrestrial eco-toxicity. Such a mix also worsens some social issues such as health impacts from radiation and radioactive waste storage requirements. UK-based employment may more than double by 2070 if a renewables-intensive mix is chosen. However, the same mix also increases depletion of elements nearly seven-fold relative to the present, emphasising the need for end-of-life recycling. Very low-carbon mixes also introduce considerable uncertainty due to low dispatchability and grid instability. With equal weighting assumed for each sustainability impact, the scenario with an equal share of nuclear and renewables is ranked best.

This paper presents life cycle environmental impacts of UK shale gas used for electricity generation, in comparison with other fossil, nuclear and renewable options. Per kWh of electricity generated, shale gas has higher environmental impacts than the other options, except for coal. Thus, if it were to replace coal, most impacts would be reduced, including the global warming potential (GWP; by 2.3 times). However, if it were to compete with nuclear or some renewables most impacts would rise, with the GWP increasing by 5–123 times. Within a future UK electricity mix up to 2030, shale gas would make little difference to the environmental impacts of electricity generation, including the GWP, even for the most optimistic assumptions for its domestic production. This suggests that, in the medium term, shale gas cannot help towards meeting UK climate change targets and that certain renewables and nuclear power should be prioritized instead.

A multi-period mixed-integer linear programming model has been developed to help explore future pathways for electricity supply where costs and carbon reduction are a priority. The model follows a life cycle approach and can optimise on costs and on a number of environmental objectives. To illustrate the application, the model has been optimised on two objectives: whole system costs and global warming potential (GWP) using the UK as an example. Four different scenarios have been considered up to 2060, each assuming different electricity demand and carbon reduction targets. When optimising on system costs, they range from £156.6 bn for the least carbon-constrained scenario with moderate increase in electricity demand to £269.9 bn for the scenario with high demand and requiring 100% decarbonisation of electricity supply by 2035. In optimisation on GWP, negative carbon emissions are achieved in all scenarios, ranging from −0.5 to −1.28 Gt CO2 eq. over the period, owing to biomass carbon capture and storage. Optimising on the GWP also reduces significantly other environmental impacts at costs comparable to optimised costs. This research shows that meeting carbon targets will require careful planning and consideration of objectives other than costs alone to ensure that optimal rather than suboptimal solutions are found for a more sustainable electricity supply.