Results 1 - 10 of 90
Results 1 - 10 of 90. Search took: 0.016 seconds
|Sort by: date | relevance|
[en] Conclusions: ♦ SMR CHP has significant role in heat demand provision considering low emissions scenarios; ♦ SMR only electricity are not built; ♦ Only SMR CHP are ‘interesting’ to PLEXOS model; ♦ Due to high variability of heat demand (season but also during week) SMR CHP has rather low heat CF; ♦ SMR CHPs are superior even to Biomas CHP plants in this model.
[en] The work here described is part of the PhD thesis that is being developed with the goal of studying the hygrothermal behavior and energy performance of several dwellings in the Dry-Mediterranean Climate. In this phase, after an annual campaign of in situ experimental tests, research now focuses on the assessment and quantification of the influence of local climate conditions and thermal values of rammed earth walls on energy demands of common traditional buildings in La Mancha. To achieve it, energy simulations have been performed on two buildings, with three goals. 1) Evaluation of construction systems which include walls with a high thermal inertia in comparison with contemporary systems. 2) Study the influence of theoretical values of walls and user activity taken from nominal data in the Catalogue of Building Components (CEC), that can be found in the Technical Building Code (CTE), and compare it with the use of actual in situ data and surveys; 3) Contrast between using standard and actual climate data recorded with a private weather station placed in the same location as the studied buildings. Research like , ,  also execute energy simulations of rammed earth buildings and components but in a different climate, while other papers like , , ,  also compare in situ values with nominal data but the main material of the studied buildings is not rammed In conclusion, results show that: 1) Energy demands of spaces where the theoretical transmittance value (or U-value) has been used are 52-55% higher in winter and 9-15% higher in summer than those where the in situ value has been used. 2) The use of theoretical information against the use of actual surveys about user activity can generate 12-26% difference in energy demands. 3) On the contrary, the use of available climate data measured at nearby locations would produce lower energy demands than using values recorded in the same location as the buildings, being up to 64% lower in winter months and up to 100% lower in summer months. Future research should be performed using combined heat and moisture models (HAMT in Energy Plus), as several studies have demonstrated that there is and important relation between thermal values and water content of the material [earth.
[en] The passive design represents a solution to the energy issue in dwellings. We should highlight the existence of several elements that take belong to the field of passive design. This work aims to study de relation between the implementation of a passive design plus an active- passive design (use of renewable energy) to apply on a dwelling and the resulting energy saving. The object of study is a 100 sq. meter dwelling placed in the top floor of a seven story building in Villaverde (Madrid). To begin Design Builder software  was used, that reaches just up to energy consumption issues. In order to know the contributions about energy saving, a comparative analysis between both (original and modified) Design Builder models. 3D models in Revit and SketchUp were done in order to make a preliminary analysis. Then a passive and an active- passive designs were chosen and keeping in mind the features of the base dwelling, using Design Builder software, for a first approach and analysis of the original model and the proposed one. At the calculation phase original model’s energy requirements were observed in order to be later compared to those of the modified model...
[en] Shortcuts to adiabaticity provide a general approach to mimic adiabatic quantum processes via arbitrarily fast evolutions in Hilbert space. For these counter-diabatic evolutions, higher speed comes at higher energy cost. Here, the counter-diabatic theory is employed as a minimal energy demanding scheme for speeding up adiabatic tasks. As a by-product, we show that this approach can be used to obtain infinite classes of transitionless models, including time-independent Hamiltonians under certain conditions over the eigenstates of the original Hamiltonian. We apply these results to investigate shortcuts to adiabaticity in decohering environments by introducing the requirement of a fixed energy resource. In this scenario, we show that generalized transitionless evolutions can be more robust against decoherence than their adiabatic counterparts. We illustrate this enhanced robustness both for the Landau–Zener model and for quantum gate Hamiltonians. (paper)
[en] As human demand for ecosystem services (ES) continues to increase, ES assessments have gradually become a popular research topic. Among ES, cultural ES (CES) are often overlooked and are difficult to measure during research because of their invisibility. However, the importance and usage of CES increase with supply and demand, which is key to linking the ecosystem with human well-being. This paper quantitatively evaluates various cultural services and generates corresponding Value Index (VI) maps; it then further explores the current dynamics of supply and demand. We selected Cuihua Mountain (CM) as the study area, and we applied the Social Values of Ecosystem Services (SolVES) model to evaluate CES and generated five specific VI maps to indicate the potential service stock (ES capacity). The actual supply (ES supply) is based on the attribute of the visibility of observation points on leisure routes, and the visitors (ES demand) to the service come from socio-economic data as a measure of the rates of access to entertainment venues. The supply and demand relationship (ES budget) solves the significant problems related to the oversupply and shortage of ES in space. The results showed that the CES supply power of CM is greater than the actual demand; thus, there is great potential for future development. This study also provided a reference and guidance for environmental decision-making and development in other regions.
[en] As much wind power is connected to the power system, the accommodation of the wind power in the power grids becomes a huge challenge to the operation model of China’s power system. Releasing and improving the flexibility of the power system will be necessary and important to enable the accommodation of power generated with renewable energy sources, which is connected to the power grids on a large scale and accounts for a high proportion. The paper, with North Hebei as an example, discusses the relationship between the demand for the flexibility of thermal power units and the accommodation of wind power. This paper further analyzes the demand for peak load regulation in North Hebei at both the present and the future as well as the characteristics of power sources in the power grids of North Hebei and the technical potential of power generation. It also compares the quantity of curtailed power before and after the flexibility-oriented transformation of thermal power units in North Hebei and calculates the minimum technical output of thermal power under different levels of accommodation of wind power. The research shows that the peak load regulating resources in the power grids of North Hebei boast huge potential, but in the long term, to achieve the objective of a 10% curtailment rate of power generated with renewable energy sources, the minimum technical output of condensing units must be lower than the internationally advanced level of 25%. So, it is difficult to fulfill the said objective solely relying on the strengthened transformation of generating units. To reach the level of 5% curtailment rate of power generated with renewable energy sources, the minimum technical output must achieve breakthrough improvement, which requires continuous technological innovation and power flexibility in close coordination.
[en] The strategic guidelines of the Armenian Long-Term State Energy Policy are Energy and Environmental Security, as well as Energy and Budget Efficiency. Nuclear Scenario Fragmentation of Energy Policy Problems: Objective - Minimization of GHG emissions in mid-century long term perspective; Criteria - Estimated Values of the appropriate positions on ecology.
[en] Rapid increase in global energy use and growing environmental concerns have prompted the development of clean, sustainable, alternative energy technologies. As one of the countries with the largest population, renewable energy sources like solar and wind are a promising solution for India. However, electrical energy storage (EES) is critical to efficiently utilize electricity produced from renewable sources as they are intermittent. EES is also the only viable near-term option to electrify the transportation sector. Rechargeable batteries are prime candidates for EES, but their widespread adoption for electric vehicles and grid electricity storage requires optimization of cost, cycle life, safety, energy density, power density, and environmental impact, all of which are directly linked to severe materials challenges. Lithium-ion batteries have aided the revolution in portable electronics for more than two decades, but the necessity of large batteries for electric vehicles and grid storage prompts the development of next-generation of low-cost battery chemistries. After providing a brief account of the current status, this presentation will focus on the development of advanced materials and new battery chemistries for near-term and long-term battery technologies. Particularly, the challenges and approaches of transitioning from the current insertion-compound electrodes in lithium-ion batteries to new conversion-reaction electrodes with multi-electron transfer to increase the energy density and lower the cost will be presented. Specifically, batteries based on lithium and sodium as working ions with high-nickel layered oxide and sulfur cathodes and interdigitated alloy anodes will be presented. In addition, low-cost systems based on solid electrolytes with aqueous electrodes will be discussed. The challenges of bulk and surface instability during charge-discharge cycling, advanced characterization methodologies to develop an in-depth understanding, and approaches to overcome the challenges will be presented. (author)
[en] Key messages: 1. To achieve 2°C and 1.5°C, leading global energy scenario studies show: • Increased nuclear power deployment (and electrification); • Complementary role for nuclear and renewables. 2. Compared to current trends, more conducive market and policy conditions are needed to unlock nuclear power’s mitigation potential.