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Abstract The development of high-performance shape-stable phase change materials composites (ss-PCMCs) with enhanced thermal conductivity and high phase change enthalpy is of great importance for thermal energy storage. Herein, we report the creation of novel ss-PCMCs by incorporation of organic PCMs (1-hexadecanamine (HDA) and palmitic acid (PA)) into the biomass carbon aerogels (BCAs refer to sunflower receptacle spongy carbon aerogel (r-CA) and sunflower stem carbon aerogel (s-CA)) through a simple vacuum infusion. Due to their abundant porosity, light weight and high specific surface area, organic PCMs can be spontaneously loaded into BCAs with an ultrahigh loading rate of up to 1988 wt%. The obtained of PCM/BCAs composites show high phase change enthalpy of ranging from 207.9 kJ kg−1 to 271 kJ kg−1, in addition to their excellent thermal stability and recyclability, e.g., their phase change enthalpy nearly remains unchanged even after 50 times of melting/freezing cycles. The PCM/BCAs composites also show an enhanced thermal conductivity. Furthermore, the light-to-thermal conversion efficiency was found to be promising candidates for light-to-thermal energy storage applications on basis of their 75.6% for HDA/r-CA and 67.8% for HDA/s-CA, respectively, making them abundant resource, cost-efficiency, simple and scalable fabrication process.

To evaluate flood-prone areas, correlation analysis of flooding factors for the quantitative evaluation of hazard degree was determined to assist in further disaster prevention management. This study used flood-prone areas in 35 villages over eight townships (Changhua, Huatan, Yuanlin, Xiushui, Puyan, Hemei, Dacun, and Erlin) in Changhua County as research samples. Linear combination was used to evaluate flood-prone environmental indices, and an expert questionnaire was designed by using the analytic hierarchy process and the Delphi method to determine the weights of factors. These factors were then used to calculate the eigenvector of a pairwise comparison matrix to obtain the weights for the risk assessment criteria. Through collection of disaster cases, with particular focus on specifically protected areas where flooding has occurred or is likely to occur, public adaptation and response capabilities were evaluated by using an interview questionnaire that contains the items of perceived disaster risk, resource acquisition capability, adaptation capability, and environment understanding and disaster prevention education. Overlays in a geographic information system were used to analyze the flood-risk degree in villages and to construct a distribution map that contains flood-prone environment indices. The results can assist local governments in understanding the risk degree of various administrative areas to aid them in developing effective mitigation plans.

Districts have a significant role in achieving the principles of sustainability. Within the past decades, a great variety of assessment tools and methodologies has been developed in an effort to ‘translate’ the sustainability criteria into applied cases. There is an increasing interest in this contribution scaled up the assessment to larger territorial analysis and urban agglomerations. Notwithstanding, developing an assessment tool with sustainable standards requires strategic approaches to incorporate the theoretical framework to their implementation of city districts by measuring their performance in a consistent manner in respect of multiple criteria. Among these issues, energy efficiency and the zero energy objectives are significant for European policies. This study aims to provide an overview of the existing assessment tools and methods comparing their criteria and key parameters. As a second step, it introduces a simplified methodological assessment theoretical tool (U-ZED) by focusing on the commitment towards the zero energy targets in a future district. In a more general perspective, the study deals with the challenge of the development of a tool from building to district with the main concern to define the context of sustainable and long-term districts dealing with the challenges of 2050 horizon.

Abstract Power-to-gas (PtG), as a promising technology proposed to store surplus renewable energy (RE), can hardly be commercialized for its low profitability. In this paper, three approaches are proposed in this paper to enhance the profitability of the PtG. Firstly, a cooperative union containing PtG is proposed and its sustainability analysis is undertaken based on Shapley Value method. Secondly, the PtG reaction heat, as an essential by-product of PtG which is valuable and therefore requires further study, is fully exploited for district heating in the operation of regional integrated energy system, which is solved by an improved SOCP method. Thirdly, a symbiosis cooperation mode is designed for wind power and PtG to enhance the benefit of PtG through optimization-based trading strategy, which is a MINLP model and solved by Big-M method. The results show that the daily profit of PtG is significantly increased with the cooperative union as the symbiosis cooperation mode can produce a 15.1% profit lift, meanwhile, exploitation of reaction heat can produce an 8.6% profit lift. Finally, our study reveals the conflict of interest between wind power and the cogeneration. A sensitivity study on the proportion of reaction heat used for district heating is performed to verify the mutually beneficial relation between PtG and the cogeneration. The findings of this paper can guide the commercialization of PtG.

Abstract This paper aims to explore the appropriate investment strategy for Chinese power enterprises with the effect of the nationwide carbon emissions trading (NCET) market. Based on the system dynamics (SD) theory and the analysis of investment strategies, the SD model for the investment analysis of power enterprises is proposed. The simulation experiments based on three different investment policy scenarios (i.e., conservative, neutral and active) are conducted. According to the simulation results, the reasonable short-term investment for enterprises should be increased. If enterprises choose to invest more resources in the installation of green powers (hydropower, wind power and photovoltaic), their carbon emissions and profits may be more difficult to achieve qualitative changes in the short term. It is suggested that before the establishment of NCET market, enterprises should give priority to investing in clean technology instead of large-scale green energy installation. In the long run, increasing the investment of green power generation will help enterprises resist the rising cost of carbon trading. In addition, even in the conservative policy environment, the enterprise can still achieve its carbon discharges peak value before 2030, so the government may consider adopting a loose policy standard to support the economic interests of power enterprises.

Abstract Risks posed by composting of municipal solid waste (MSW) depend on the assessment approach used. Occupational risks at present are not overtly serious— only nausea, eye irritation, etc. are reported from inhalation, the chief exposure pathway—but details are lacking on outcomes of pathogenic, chemical and physical threats, including potential secondary problems with organisms developed in compost, their endotoxins, and metabolic products such as aflatoxin. Potential risk pathways of public exposure to MSW compost are dominated by children's lead ingestion, but “dioxins” and other persistent organic carcinogens are also of dietary concern. Risks to the “most exposed individual” (MET) may differ substantially from those based on the Alternative Pollutant Limit (APL) approach. Neither deals adequately with uncertainty or multiple pathway/chemical threats to public and environmental health. Additional issues include (a) incremental vs. total risk, (b) required nutrient intake vs. proscribed toxicant exposure (for the same element) and (c) long-term matters of “no net degradation,” and composting in recycling.

Abstract Biofuels are controversial because of uncertain environmental benefits and reported social drawbacks, including ‘land grabs’ and threats to food security. The present study investigates the relevance of these concerns for a proposed bioethanol project in Cradock, South Africa. The proposed project is anticipated to lead to economic upliftment and could therefore contribute to reduce poverty and thus strengthen food security. With a projected annual production of up to 16,000 l ethanol per hectare, yields would be substantially higher than in most other countries. Agricultural activity would take place on existing farm land, or on biomes classified as ‘least concern’. We estimate a carbon footprint reduction of ~ 30% for sugar beet ethanol in the area. Because various global biofuel concerns do not apply to the proposed Cradock fuel ethanol project, we argue for a more nuanced approach for the evaluation of biofuel projects with more focus on case-specific attributes.

The Swedish energy system is undergoing a transformation due to threats about climate change and political decisions to reduce green house gases and to phase out the nuclear power. The goal is to convert the energy system from a system based on fossil fuels and nuclear power to one based on renewable energy sources. Bioenergy is an available domestic, renewable, carbon dioxide neutral energy source and therefore an increase of the use is forecasted in the future. Studies have shown that bioenergy may cause negative impacts on human health and on the environment due to emissions to air. The aim of this study was to investigate how a future conversion to bioenergy-based heating affect the air quality in residential areas. The contribution of particulate matter (PM10) and benzene from existing heating systems as well as from conversion from electrical heating and firewood boilers to pellets and small-scale district heating systems was investigated. The investigations included monitoring of energy need for heating, identifying suitable energy systems for conversion, identifying emission factors, dispersion calculations and application of the results in a geographical information system (GIS). The results show that conversion from electrical heating to pellets in the investigated areas does not affect the air quality. The GIS maps showed the expected concentrations caused by small-scale combustion of bioenergy-based fuels clearly. The dispersion pattern of the emitted gases and particulates was visualized and the maps can be used for planning purposes when dealing with new residential areas.

Sustainable methods are required to reduce the risks of thermal strain and heat-related illness without exacerbating greenhouse gas emissions. We investigated the effects of sun-shade use on safe heat exposure limit on a sunny summer day using historical climate data in Japan. We simulated a heat-acclimatised person standing at rest (metabolic heat production, 70 W·m-2) and during light work (100 W·m-2) on an asphalt pavement in the sun and sun-shade. Japan has three Köppen climate regions: tropical, temperate and cold. We analysed one city in the tropical region (24°N), three cities in the temperate region (31°N, 35°N and 39°N) and one city in the cold region (40°N). Hourly data were collected from 7 AM to 6 PM, June to September, from 2010 to 2019. The day with the longest daylight hours and the greatest solar radiation intensity was used for analysis. With sun-shade (a white polyester tarpaulin/awning), ambient temperature, global solar radiation and ground surface temperature were assumed to be 0.5°C, 45% and 6°C lower than in the sun, respectively. Sun-shade use eliminated the days with at least 1 hour exceeding safe heat exposure limit at rest in all cities. The same was observed for light work in the temperate and cold cities, although the tropical city had 2 days exceeding safe heat exposure limit during the decade. Sun-shade use on a sunny summer day can be an effective and sustainable method to reduce heat exposure hazard at rest and during light work in tropical, temperate and cold climate regions.

Regional and local decision-makers still require relevant information and training in order to establish long-term strategies and to contribute to national and supranational energy and climate targets. As an example, a widespread participation of local authorities to comply with the Italian long-term building renovation strategy has not occurred so far. Thus, the overall target, annual 1% floor area of new or deeply renovated buildings to the nearly zero-energy building (nZEB) standard by 2020 (PanZEB 2015), proves to have been disregarded to date. Evidence-based, data-enabled assessment of the building stock and of its relationship with the energy system as a whole at a capillary level is crucial to this extent. In Italy, various building databases are already being used with the ultimate purpose of EPBD implementation and to track and record incentives for public and private building renovation. These datasets have an untapped potential for local energy planning that could be released from wider integration, also including energy consumption data and smart-metering data. Moreover, the regulatory landscape is changing toward an interaction of the building with the user, the energy grid and other buildings in a dynamic and functional way. Within this context, the paper will investigate how integrated data could unlock the value of a more evidence-based planning starting from the DIPENDE integrated dataset, a REQUEST2ACTION (IEE 2014–2017) pilot project combining data from energy performance certificates (EPCs) with bottom-up information on building renovation, and other data in order to support decision making at different territorial scales.