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Abstract The 21st Conference of the Parties (COP21) of the United Nations Framework Convention on Climate Change (UNFCCC) marked a milestone in the course of international efforts on global climate action. As part of the COP21 side events, on December 4th the Lima Paris Action Agenda presented a half-day of presentations and round table discussions titled Focus on Private Finance. The event was supported by the Secretary-General of the United Nation, Caisse des Depots, and the I4CE Institute for Climate Economics. This conference report summarizes the findings of the session and the messages delivered by finance industry representatives. Significant investment in low carbon assets is required to maintain global temperature increases below 2 °C. The two resounding themes throughout the session were that in order to attract capital for low carbon investments fossil fuel subsidies must end and a higher carbon price is needed to incentivise investment. Furthermore, accounting and regulatory bodies need to implement more stringent disclosure and reporting requirements so that climate risk is properly understood by investors. There is significant appetite for investment in the low carbon sector which is demonstrated by the growth in the green bond market. Financial institutions have a role to play in aggregating, structuring and de-risking investments to facilitate private finance investment. Policy makers also need to improve the investment environment by creating consistent and stable long term policies which will give investors' confidence.

Abstract The sustainable indicators are characterized by a low degree of aggregation and a high amount of information. An indicator must show a synthetic representation of a real environmental, by using a value or a parameter, so that they can be easily used by policy makers. It is necessary to connect, therefore, the various systems in an appropriately integrated sustainable system. The indicators need to be aggregated based on the structure of the data. Each indicator must to be defined through a weight with reference to another weighted indicator. In this paper is illustrated the calculation of the assigned weights that uses a procedure based on fuzzy logic and to define a model that allows us to estimate the sustainability of a city. The final result is, therefore, a combination of values assigned by expert opinion for the various criteria, processed using fuzzy logic to obtain a weight with significant objectivity and as it is possible to estimate the sustainability of the city through the weights.

Abstract In recent years, distributed energy systems (DESs) have been recognized as a promising option for sustainable development of future energy systems, and their application has increased rapidly with supportive policies and financial incentives. With growing concerns on global warming and depletion of fossil fuels, design optimization of DESs through economic assessments for short-run benefits only is not sufficient, while application of exergy principles can improve the efficiency in energy resource use for long-run sustainability of energy supply. The innovation of this paper is to investigate exergy in DES design to attain rational use of energy resources including renewables by considering energy qualities of supply and demand. By using low-temperature sources for low-quality thermal demand, the waste of high-quality energy can be reduced, and the overall exergy efficiency can be increased. The goal of the design optimization problem is to determine types, numbers and sizes of energy devices in DESs to reduce the total annual cost and increase the overall exergy efficiency. Based on a pre-established DES superstructure with multiple energy devices such as combined heat and power and PV, a multi-objective linear problem is formulated. In modeling of energy devices, the novelty is that the entire available size ranges and the variation of their efficiencies, capital and operation and maintenance costs with sizes are considered. The operation of energy devices is modeled based on previous work on DES operation optimization. By minimizing a weighted sum of the total annual cost and primary exergy input, the problem is solved by branch-and-cut. Numerical results show that the Pareto frontier provides good balancing solutions for planners based on economic and sustainability priorities. The total annual cost and primary exergy input of DESs with optimized configurations are reduced by 21–36% as compared with conventional energy supply systems, where grid power is used for the electricity demand, and gas-fired boilers and electric chillers fed by grid power for thermal demand. A sensitivity analysis is also carried out to analyze the influence of energy prices and energy demand variation on the optimized DES configurations.

Thermal energy storage systems (TES) based on shape-stabilized phase change materials (SSPCM) designed from recycled Tetra Pak (TP) waste, paraffin wax (PW), and expanded graphite (EG) were investigated in this study. This work represents the first study to explore TP waste composed of low-density polyethylene (LDPE)/aluminum (Al) components for energy storage applications. The LDPE part serves as a matrix conserving a material in a compact, solid shape after PW melting; PW acts as an active phase change component contributing to heat absorption/release through a phase change (from a solid to a liquid state, and vice versa) of its crystalline phase. EG serves as a filler that enhances the thermal conductivity and mechanical properties of materials. The focus was put on the optimization of the composition of SSPCM including PW, and EG, to check thermal, mechanical, and rheological properties which influence the future processability of such systems through extrusion, as well as to investigate the synergic effect of graphite and residual Al component on thermal conductivity and leakage of PW. There are two main demands on polymer/PW blends, namely well-separated melting peaks for both components at significantly different temperatures, and good compatibility between polymer and PW. The best performance of SSPCM investigated in this study was found for a mixture having the composition TP/PW/EG = 50/40/10 w/w/w. This mixture shows well-balanced properties, including appropriate heat storage and release parameters, thermal conductivity, thermal diffusivity, toughness and strength, and low leakage of PW from the material. This system can store 116.2 J/g of heat energy and release 93.8 J/g of heat energy. The determination of the heat energy storage and release was performed by the transient guarded hot plate technique. Tensile testing revealed that Young's modulus of the TP/PW/EG = 50/40/10 w/w/w composition was 924 ± 71 MPa and the stress at break was 8.2 ± 1.2 MPa, which are sufficient values from the applicability ...

While the member states of the Gulf Cooperation Council have economically and politically been dominated by the exploitation of fossil fuels, recent years have seen an increasing adoption of renewable energy technologies, the reasons of which are not yet sufficiently understood. This paper argues that the recent adoption of renewable energy technologies in the Gulf and its striking variation can be explained by theories of policy transfer. In addition, we find some support for the alternative hypothesis of endogenous policy development regarding political leadership. Yet there is no support for the alternative hypothesis of a strong direct influence of the international climate regime. Furthermore, the policy transfer hypothesis and political leadership stand as coexisting influences on renewable energy adoption, rather than competing ones. Based on an extensive study of primary and secondary sources, local reports and country analyses of international organizations, and personal interviews with key experts, this paper lays out in detail how transfers of renewable energy policies take place in the Gulf; their drivers; and their impacts. We also discuss the factors that lead countries to lag behind, which can be helpful for prospective research on a more extensive utilization of renewable energy in the region and beyond.

Abstract This paper assesses the effects of a global emissions trading scheme (GETS) for international aviation and shipping as a way of reducing emissions of both greenhouse gases (GHG) and other atmospheric emissions that lead to air pollution. A prior assessment of such integration requires the coupling of energy–environment–economy (E3) global modelling of mitigation policies with the atmospheric modelling of pollution sources, mixing and deposition. We report the methodology and results of coupling of the E3MG model and the global atmospheric model, p-TOMCAT. We assess the effects of GETS on the concentrations of atmospheric gases and on the radiative forcing, comparing a GETS scenario to a reference BASE scenario with higher use of fossil fuels. The paper assesses the outcome of GETS for atmospheric composition and radiative forcing for 2050. GETS on international shipping and aviation reduces their CO 2 and non-CO 2 emissions up to 65%. As a consequence atmospheric concentrations are modified and the radiative forcing due to international transport is reduced by different amounts as a function of the pollutant studied (15% for CO 2 , 35% for methane and up to 50% for ozone).

PurposeValue chain analysis (VCA) can expose strategic and operational misalignments within chains, and the consequential misallocation of resources, and hence opportunities for improvements which create value and economic sustainability. This paper's purpose is to argue why and how VCA needs to integrate the social and environmental aspects of sustainability in pursuit of sustainable competitive advantage.Design/methodology/approachBased on a review of existing methods and case studies, the paper proposes three dimensions of VCA, which illustrate the flaws in narrow tools, and the need to broaden the boundaries of VCA, the interpretation of “value” and relationships along the chain in order to highlight opportunities for creating sustainable value chains.FindingsTo date VCA has largely focused on economic sustainability and paid inadequate attention to social and environment consequences of firm behaviour and the (re) allocation of resources within and between firms in the chain. This risks producing recommendations which either ignore the competitive advantage offered from improving environmental management and social welfare, or have such detrimental external consequences as to render any proposals unsustainable when exposed to government or broader (public) scrutiny.Research limitations/implicationsVCA variants need to be developed which incorporate all three pillars of sustainability. Some initial experiences are presented and ideas for future research and applications proposed.Practical implicationsThe development of sustainable VCA tools should identify business opportunities consistent with Porter and Kramer's imperative for value chains to create shared value between business and society.Originality/valueAdopting the broader dimensions identified will allow VCA to become more widely applicable, and more relevant in business scenarios where there is a growing imperative to include social and environmental impacts into “mainstream” business strategies.

Energy supply is a global hot topic. The social and political pressure forces a higher percentage of energy supplied by renewable resources. The production of renewable energy in form of biomethane can be increased by co-substrates such as municipal biowaste. However, a demand-driven energy production or its storage needs optimisation, the option to store the substrate with its inherent energy is investigated in this study. The calorific content of biowaste was found unchanged after 45 d of storage (19.9±0.19 kJ g(-1) total solids), and the methane yield obtained from stored biowaste was comparable to fresh biowaste or even higher (approx. 400 m(3) Mg(-1) volatile solids). Our results show that the storage supports the hydrolysis of the co-substrate via acidification and production of volatile fatty acids. The data indicate that storage of biowaste is an efficient way to produce bioenergy on demand. This could in strengthen the role of biomethane plants for electricity supply the future.

The configuration of a biologically fertile substrate for edible plant growth during long-term manned missions to Mars constitutes one of the main challenges in space research. Mars regolith amendment with compost derived from crew and crop waste in bioregenerative life support systems (BLSS) may generate a substrate able to extend crew autonomy and long-term survival in space. In this context, the aim of our work was threefold: first, to study the geochemistry and mineralogy of Mojave Mars Simulant (MMS-1) and the physico-chemical and hydraulic properties of mixtures obtained by mixing MMS-1 and green compost at varying rates (0:100, 30:70, 70:30, 100:0; v:v); secondly, to evaluate the potential use of MMS-1 as a growing medium of two lettuce (Lactuca sativa L.) cultivars; thirdly, to assess how compost addition may impact on sustainability of space agriculture by exploiting in situ resources. MMS-1 is a coarse-textured alkaline substrate consisting mostly of plagioclase, amorphous material and secondarily of zeolite, hematite and smectites. Although it can be a source of nutrients, it lacks organic matter, nitrogen, phosphorus and sulphur, which may be supplied by compost. Both cultivars grew well on all mixtures for 19 days under fertigation. Red Salanova lettuce produced a statistically higher dry biomass, leaf number and area than Green Salanova. Leaf area and plant dry biomass were the highest on 30:70 simulant:compost mixture. Nevertheless, the 70:30 mixture was the best substrate in terms of pore-size distribution for water-plant relationship and the best compromise for plant growth and sustainable use of compost, a limited resource in BLSS. Many remaining issues warrant further investigation concerning the dynamics of compost production, standardisation of supply during space missions and representativeness of simulants to real Mars regolith.