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Abstract Understanding China’s GHG (greenhouse gas) emission status is critical for achieving the national mitigation plan. While much attention has addressed China’s national level GHG emission, less is known about its regional and sectoral emission features. In this paper China’s regional and sectoral GHG emission patterns and their driving forces were explored by using upgraded energy consumption data. We constructed a detailed GHG inventory for each province in the year 2009 which covering 28 sectors and further expanded time-serious inventories during 1997–2009. We then conducted variation and index decomposition analysis to explore its sectoral/regional disparity and features. Results showed significant differences of sectoral emission intensity among different provinces, implying a huge disparity of technology level. Since less developed provinces still apply energy intensive technologies, they had contributed to most of national emission increment during 1997–2009 and made the whole country towards carbon intensive direction. Our research outcomes indicate that the inequity of technology level among regions has already become a main barrier for China’s CO 2 mitigation. Such a reality deserves more attention from both researchers and policy makers so that appropriate carbon reduction policies can be raised.

This paper presents a new methodology that allows to define a 100% renewable smart energy system in a sustainable manner. The authors integrate the EnergyPlan with a mathematical model that analyzes the energy system from an exergetic point of view taking into account the exergy of the whole energy system and its components. Once multiple scenarios are obtained by EnergyPLAN, the exergetic model identifies the scenario characterized by the highest exergetic efficiency and the lowest energy wasting. This approach is a novelty since the "exergetic" optimization criterion coupled with EnergyPLAN software has never been utilized. Since the best energy system could not be economically attractive, this methodology might support Municipalities in setting up focused incentives to make the sustainable solutions the most cost effective too. The authors present a case study by applying the new methodology to the city of Pompeii. The results show that the best solution provides 21.0 MWe capacity of PV plant, integrated to 8.10 MWe of CHP plant. Due to a high value of critical excess electricity production, 10 MWe heat pumps must be installed. Finally, a solar thermal plant is installed. The proposed system could be only realized if new incentives are provided.

Abstract This paper presents an innovative water photovoltaic thermal collector prototype. One of the main novelties of such system is its economic affordability, obtained through low-cost materials. The collector, constructed and experimentally tested at the University of Patras (Greece), is composed of a polycrystalline photovoltaic module coupled to eleven plastic pipes for water heating, located under the PV panel in an aluminium box. The prototype, suitable for building architectonical integration, can provide domestic hot water and electricity to the building. In order to assess the energy, economic and environmental performance of the system under different weather conditions and for diverse building uses, a suitable dynamic simulation model was developed and validated vs. experimental data. To investigate the convenience of the presented prototype and the potentiality of the developed software, a suitable case study is presented. In particular, the photovoltaic thermal collector is coupled to a stratified hot water storage tank for supplying domestic hot water to a single-family house located in three different European weather zones: Freiburg, Naples and Almeria. The system layout optimization was also performed through an energy and economic sensitivity analysis to some design and operating parameters. Useful design criteria and interesting energy and economic results were obtained.

This paper analyses the policy relevance of the dominant uncertainty in our current scientific understanding of the terrestrial climate system, and provides further evidence for the need to radically transform-this century-our global energy supply infrastructure, given the global average temperature increase as a result of anthropogenic carbon dioxide (CO

Abstract Growth of urban population around the world and, particularly, within urban areas, has placed various pressing challenges on Food, Energy, and Water (FEW) such as food security, water safety as well as energy scarcity and so on. Current studies on urban FEW nexus are mainly focused on the correlation analysis of elements by pairs, while these works are developed separately. With respect to the methods, the existing researches mostly adopt the bottom-up approach, accounting for the direct relationship between the individual production sectors. While the associations between the internal elements of the system still lack of simulation. In this study, we aim at developing an online open access tool for cities, the Urban Circular Economy Calculator (UCEC), which enables to develop different circular economy scenarios associated to FEW management. UCEC v1.0 uses Beijing data as test case. In particular, more than 20 circular economy policies related on food, energy and water are selected and divided into 6 categories. Long-term simulations on the social, economic and environmental impacts are provided to test the trajectories of policy effects. Being an open access tool, UCEC can be used also for supporting participatory processes as an urban management instrument. The solution is economically and financially feasible, due to the low level of technical requirements. The necessity of such a tool is proved by the societal need of transition toward a low-carbon and sustainable framework, which can be effectively supported by the introduction of circular economy. This transition, such as the idea behind UCEC, should preserve (or even improve) the societal wellbeing, while increasing basic resources (i.e.: FEW) accessibility, security and preservation.

An exergoeconomic analysis of a hybrid power generation cycle is performed on its standalone constituents. The hybrid is based on Allam cycle configuration. Allam cycle is a supercritical carbon dioxide oxy-combustion (OC) Brayton cycle. The proposed hybrid utilizes solar power as its primary heat source and natural gas OC as a complementing heat source. The purpose of the complimenting heat source is to make up for the lost time when the sun is not available due to bad weather conditions or at nighttime. This is done to ensure the reliability, responsiveness, and availability of the cycle for power generation at all times. The hybrid is an attempt to provide power with minimal adverse effects on the environment. This study is divided into three major steps. The first and second are energy and exergy analysis. The third step is exergoeconomic analysis to obtain the cost contribution of each component relative to the cycle’s final product. Although both configurations brought similar power output and second law efficiency, the energy efficiency was higher for the OC configuration. The total product cost ($/GJ) for the OC configuration was half of that for the concentrated solar power (CSP). The unit cost of electricity in (Cent/kWh) for the CSP standalone configuration is approximately 60% higher than that of the OC configuration. In the CSP configuration, the main heat exchanger and the recuperator are the most critical units to consider for savings. Therefore, reducing the exergy destruction in the CSP main heat exchanger and the recuperator units could be cost-effective for the entire cycle, even if this would increase the component investment costs. Therefore, for exergoeconomic performance enhancement, using a recuperator with higher efficiency is recommended. On the other hand, the combustor and air separation unit (ASU) are the most critical units to consider for savings for the OC configuration. Therefore, a replacement for the ASU unit with a lower purchasing cost is recommended for overall exergoeconomic performance enhancement. The parametric study results showed that increasing the turbine’s inlet temperature is conducive to improving both configurations' thermodynamic and exergoeconomic performances. Similar trends were also obtained for the turbine inlet pressure for both configurations. Conference Proceedings of the European sCO2 Conference4th European sCO2 Conference for Energy Systems: March 23-24, 2021, Online Conference, p. 363

We study the valuation of preferences for small scale initiatives in renewable electricity generation. We analyse the results of a stated choice experiment among 507 respondents in The Netherlands and provide valuations of characteristics of small scale initiatives. Respondents prefer installing the capacity in small to medium sized groups and their preferred location for the generation capacity is at sea, followed by their own roofs. People that already consume green electricity, as well as those that have indicated to be willing to generate energy locally, are less price sensitive than others. Our results suggest that there is ample scope for expanding the role of micro-generation. © 2014 Elsevier Ltd.