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AbstractInvestment cost associated to the generation of renewable energy such as wind and solar is generally estimated to be higher. As the wind and solar energy generation do not require any fuel, the marginal cost of electricity generation through renewable energy technologies is very low. Therefore, in the long run, the prices are expected to get reduced, once investment cost is recovered; whereas, in the short run, the expected energy price of electricity increases.However, the final electricity price depends on several factors such as distribution cost, operating cost, storage cost (if any), load factor, and cost associated to switching of technology for electricity generation through total energy mix. In case of solar and wind energy generation, the technologies have grid priorities, but solar and wind are highly sensitive to weather conditions. Therefore, to make the system efficient, an energy system also depends on coal fired plant, gas fired plants, nuclear plants, biomass, hydro, etc. for meeting the energy supply needs. Based on overall capacities, investment costs, energy imports and fuel prices, the final electricity prices are decided. With the current trends in advancement of technologies, and priority for one technology over the other, the prices can still fluctuate in the future.In the current energy literature, methods available for price forecasting followed the modelling approaches that use range of variables for forecasting the possible scenarios. These scenarios and forecasting might affect an investment decisions of investors. However, the challenging future scenario in European energy mix addresses the issue of falling electricity price while the renewable energy technologies getting cheaper; which tends to freeze further investments, unless sufficient government support is available.The current study aims to explore the various economic forecasting methods presented in the literature for the purpose of energy price modelling, in different contexts, such as geographies, demand, supply, marketing, strategy, etc. The results suggest a large variation in the methodologies being used by scientists to address the issues in different countries. A wide range of variable selection approach has been observed. Our study suggests that the current market has not researched well on long run forecasting methods. This study also aims to present some thoughts on energy marketing in the context of emerging economies, such as India for the energy policy framing.

AbstractIn order to increase the thermal efficiency and produce process heat for hydrogen production, the operating temperature of the heat transfer fluid in thermal solar plants needs to increase. In addition reaching 900°C would also increase the heat storage density and the efficiency of the thermodynamic cycle by using a combined cycle for electricity production. The benefits of hydrogen (e.g., for fuel cells) and a more efficient thermodynamic cycle would allow a plant to have a higher energy output per square acre of land use, thereby increasing its economic competiveness.Today, solar thermal plants do not operate at these high temperatures due to the fact that conventional heat transport fluids begin to disintegrate around 600°C [1,2]. For non-solar applications, low melting-temperature metals, such as wood's metal and lead- bismuth eutectic alloy, have been examined as heat-transport media, because of the large temperature ranges over which they remain liquid. Lead-bismuth eutectic alloy (LBE; 45% Pb, 55% Bi) melts at 125°C and does not boil until 1670°C, making it an ideal heat-transfer medium for application in thermal solar power [3]. The main obstacle to using LBE is finding structural materials that can withstand the harsh corrosion environments at high temperatures. In this work the key issues of materials exposed to liquid metal are described while initial data on carious steels tested in liquid metal are provided. While corrosion is a significant issue in this environment, mechanical failure of steels in liquid metal are discussed as well.

Abstract While small and medium size biomass combined heat and power (CHP) plants (i.e., up to 5 MW of electrical rated power) represent an attractive option to exploit locally available biomass resources at low cost, the corresponding investment per unit of rated power significantly rises when the installed power decreases. In these cases, secondary pollutant emissions control measures are most of the time not economically viable and primary emissions control must be used alone to avoid the formation of undesired compounds such as NO x and SO x . Primary control measures require the careful optimization of fuel quality and combustion process. For plant operators, being able to accommodate biomass quality changes in order to minimize the fuel cost can be of great importance in order to guarantee the profitability of the plant. This contribution is dedicated to the development of a zero-dimensional (input–output) combustion simulation model able to predict the pollutants emissions resulting from complete and incomplete combustion with respect to varying combustion operation (ambient temperature, humidity, fumes recirculation, …). This tool is intended to be integrated in a global simulation model of the CHP plant and the attached district heating network installed on the University campus in Liege. Doing so, the plant operation can be optimized with respect to economic as well as environmental and energetic aspects (3E approach) thus ensuring the sustainability of the approach.

Purpose The main aim of the study is to assess the environmental and economic impacts of the lodging sector located in the Himalayan region of Nepal, from a life cycle perspective. The assessment should support decision making in technology and material selection for minimal environmental and economic burden in future construction projects.Methods The study consists of the life cycle assessment and life cycle costing of lodging in three building types: traditional, semi-modern and modern. The life cycle stages under analysis include raw material acquisition, manufacturing, construction, use, maintenance and material replacement. The study includes a sensitivity analysis focusing on the lifespan of buildings, occupancy rate and discount and inflation rates. The functional unit was formulated as the ‘Lodging of one additional guest per night’, and the time horizon is 50 years of building lifespan. Both primary and secondary data were used in the life cycle inventory.Results and discussion The modern building has the highest global warming potential (kg CO2-eq) as well as higher costs over 50 years of building lifespan. The results show that the use stage is responsible for the largest share of environmental impacts and costs, which are related to energy use for different household activities. The use of commercial materials in the modern building, which have to be transported mostly from the capital in the buildings, makes the higher GWP in the construction and replacement stages. Furthermore, a breakdown of the building components shows that the roof and wall of the building are the largest contributors to the production-related environmental impact.Conclusions The findings suggest that the main improvement opportunities in the lodging sector lie in the reduction of impacts on the use stage and in the choice of materials for wall and roof.

Shopping centres are significant built assets and part of the urban fabric in most developed economies. Yet very few studies have conducted a life cycle assessment of shopping centres, despite them using significant amounts of energy and resources throughout their life cycle. This paper presents a parametric model that quantifies the life cycle embodied flow (LCEF) and material cost (LCMC) of Australian shopping centres to inform material selection. Different combinations of building materials and assemblies are identified with minimum LCEF and LCMC for 13 different shop categories typical in shopping centres. The parametric model is used to simulate a case study centre which tests and analyses over 8820 scenarios and delivers benchmark values for the LCEF and LCMC of shopping centres. It shows that a typical centre using concrete and steel, average embodied flow intensities are 14.2 GJ/m2 and 830 kgCO2e/m2. It further demonstrates recurrent embodied flow, which is currently disregarded, is significant and represents up to 56% of the LCEF of a shopping centre over a period of 50 years. Results show that specific assembly combinations could achieve up to 32% LCEF reductions while saving up to 17% on material costs. Foundations and roof structure are identified as the most crucial of building elements for reducing embodied flow in the centre structure. This paper contributes to the embodied environmental impact assessment efforts and the energy-cost nexus by facilitating the appraisal and demonstrating broader societal impacts in making the built environment more economically and environmentally sustainable.

The development of the vehicles powered by photovoltaic (PV) is desirable and very important for reducing CO2 emissions from the transport sector to realize a decarbonized society. Although long‐distance driving of vehicle‐integrated PV (VIPV)‐powered vehicles without electricity charging is expected in sunny regions, driving distance of VIPV‐powered vehicles is affected by climate conditions such as solar irradiation and outside temperature, and the power consumption of the air conditioners. In this article, analytical results for system efficiency of VIPV‐powered vehicles and the effects of usage of air conditioner are presented by using power losses estimated from the electric mileage by using the driving distance data for Toyota Prius and Nissan Van demonstration cars installed with high‐efficiency InGaP/GaAs/InGaAs three‐junction solar cell modules with a module efficiency of more than 30%. The potential of VIPV‐powered vehicles to be deployed in major cities in Japan and the world is also analyzed. Mild weather cities such as Miyazaki in Japan and Sydney in Australia are thought to have longer driving range even under usage of air conditioners. The other power losses for the VIPV such as temperature rise of VIPV modules and partial shading estimate the previous data and some reference as well as effects of usage of air‐conditioners are also discussed in this article.

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.

This perspective article aims to identify key research priorities to make the waste-to-energy sector compatible with the societal goals of circularity and carbon neutrality. These priorities range from fundamental research to process engineering innovations and socio-economic challenges. Three focus areas are highlighted: (i) the optimization of flue gas cleaning processes to minimize gaseous emissions and cross-media, (ii) the expansion of process control intelligence to meet targets for both material recovery and energy recovery, and (iii) climate neutrality, with the potential for negative emissions via the removal of atmospheric carbon dioxide across the full cycle of the waste resource. For each area, recent research trends and key aspects that are yet to be addressed are discussed.