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Heat recovery devices can help ventilation systems conserve energy; However, they cause a pressure drop in the system, and hence the system incurs an electricity consumption. In the present paper, the maximum allowable pressure drop of the recovery units is achieved from thermodynamic and economic points of view. The novelty of the research is that, unlike the existing criterion which does not differ for different cities, the introduced criteria can be calculated for each city with individual weather, economic, power plants, and energy conditions. Although the methods presented to calculate the criteria consider a broad range of effective parameters, there is no need to use complex energy simulation methods. Moreover, for each city, four types of criteria are introduced, which allows the city authorities to choose the best ones according to their city conditions, and then calculate the chosen criteria by the data of the city. In order to gain the criteria, modified enthalpy-hours and bin method variables are introduced to calculate sensible and latent energy consumption due to ventilation. The criteria are numerically calculated for Kerman city in Iran, and the results show that the recovery type and the chosen viewpoint has a considerable effect on the allowable pressure drop. The sensitivity of the results to different variables is analyzed in the end. [ABSTRACT FROM AUTHOR]

The integration of multiple energy systems (MES) provides opportunities to explore the flexibility to accommodate more renewable energy. The concept and methodology of energy hub (EH) enable the standardized modeling of district MES. However, current EH formulations introduce nonlinearities into the modeling and present challenges to analysis and optimization. This paper proposes an automatic and linearized modeling method to formulate energy conversion in EHs, which simplifies the optimization of EH operations. On this basis, the flexibility of an EH is analyzed and quantitatively evaluated based on the ranks of the coupling matrices of the EH and its feasible operational region. Finally, an application of the linearized model on the interval optimization model is illustrated to show how it can suppress uncertainties and fluctuations in distributed renewable energy. A case study is used to demonstrate the effectiveness of the proposed model and the rationality of the flexibility analysis by comparing two EHs with different flexibilities. [ABSTRACT FROM AUTHOR]

In order to achieve greater energy sustainability, the European Union has begun the reform process of the energy policy. Two main lines have been raised: electricity generation with renewable energy and energy saving. The raising cost of energy makes indoor lighting techniques as one of the most important contributors for energy saving in most of the industrialized countries. Therefore, the history of indoor lighting is not exclusively linked to the development of new light sources, having impact on energy saving and sustainability. The aim of this paper was to study and analyse the evolution and milestones of indoor lighting from incandescent bulbs to the modern light-emitting diodes (LEDs) and organic lighting emitting diodes (OLED) going through intermediate milestones like fluorescent lamps (FL) and/or techniques in lighting induction lamps. As main conclusion of this review, it has been found that indoor lighting techniques with their energy efficiency have opened new perspectives for optimizing the energy conversion and this in turn will play a major role in people's quality of life and well-being. [ABSTRACT FROM AUTHOR]

Abstract: This paper deals with the method of how to regenerate the potential energy for a hybrid hydraulic excavator (HHE). After studying the structure and working cycle of the HHE, two energy regeneration systems are considered. Then, the control strategy and parameter matching for the proposed energy regeneration system (ERS) are discussed. United simulations with AMEsim and MATLAB/simulink for the conventional control system and two ERSs are carried out in this paper. An estimated 41% of the total potential energy could be regenerated at the lowering of the boom in accumulator-motor-generator system while the recovery efficiency in the motor-generator system is only about 17%, and it is also shown that the accumulator-motor-generator energy regeneration system (AMGERS) features better speed control of the boom and response characteristics than the motor-generator energy regeneration system (MGERS), hence, the AMGERS is a good configuration for the HHE at present. [Copyright &y& Elsevier]

Abstract: Constructing an indicator to measure the effectiveness of energy management is important for energy agencies and authorities. This paper uses multiple linear regression method and data envelopment analysis to examine the effectiveness of energy management. First, the regression method using environmental factors is used to calculate the predicted energy usage intensity of each evaluated building. Data envelopment analysis is then employed to calculate overall energy efficiency, using the predicted energy usage intensity as output and the observed energy usage intensity as input. Data envelopment analysis can be further applied to measure the overall energy efficiency in details by examining environmental factors and management factors. Finally, the energy consumption of buildings can be measured to evaluate the effectiveness of energy management. Buildings examined as a case study in this paper are government office buildings in Taiwan. The results show that most of the buildings evaluated to report a higher predicted energy usage intensity have successfully used efficient energy management methods in energy saving. [Copyright &y& Elsevier]

Renewable energy consumption has a strong driving force for promoting energy conservation and emission reduction, and is a new way to achieve clean and low-carbon development. Based on this, this paper uses the data of renewable energy consumption, carbon productivity, GDP, population, energy efficiency and technological innovation of 30 provinces in China from 2011 to 2020, and empirically analyzes the impact of renewable energy consumption on carbon productivity in 30 provinces in China, using STIRPAT model, comprehensively considers spatial horizontally and temporal vertically dimension. The empirical results show that: (1) China's carbon productivity shows a significant spatial spillover effect, its impact can spill over to adjacent areas within 1000 km; (2) China's renewable energy power consumption plays a significant role in promoting the improvement of carbon productivity. (3) Renewable energy consumption in the western region plays the most important role in driving carbon productivity. Finally, according to the temporal and spatial relationship between renewable energy consumption and carbon productivity in different regions, we provide specific regional policy suggestions. • The STIRPAT model is employed to explore temporal and spatial impact, while it considers sub regions. • Spatialy, the impact can spill over to adjacent areas within 1000km. Temporally, the impact fluctuates and rises. • The positive role of renewable energy consumption is found in China's western region. [ABSTRACT FROM AUTHOR]

Is there a trade-off between spending on the green economy and an economy's strength? This paper addresses this question by estimating output multipliers for spending in clean energy and biodiversity conservation, and by comparing these to multipliers of spending on non-ecofriendly energy and land use activities. Using a new international dataset, we arrive at two key results. First, we find that every dollar spent on key carbon-neutral or carbon-sink activities can generate more than a dollar's worth of economic activity, whereas non-green spending returns less than a dollar. Second, for categories of spending where formal comparisons are possible, like renewable versus fossil fuel energy, we find that multipliers on green spending are about twice as large as their non-green counterparts. The point estimates of the multipliers are 1.1–1.7 for renewable energy investment and 0.4–0.7 for fossil fuel energy investment, depending on horizon and specification. These findings survive several robustness checks and lend support to bottom-up analyses that find that stabilizing climate and reversing biodiversity loss go hand in hand with economic prosperity. [ABSTRACT FROM AUTHOR]

Abstract: Liquid desiccant air-conditioning system is a novel air-conditioner with good energy saving potential. For the liquid desiccant air-conditioning system, the energy consumption mainly relies on the regeneration process of desiccant solution. As the regeneration process of the liquid desiccant air-conditioning system only needs low-grade energy, solar energy (a kind of renewable energy) can be used to regenerate the desiccant solution and the solar desiccant regeneration system has attracted many attentions. In this paper, recent theoretical and experimental works on solar thermal regeneration method and solar electrodialysis regeneration method of the liquid desiccant air-conditioning system are extensively reviewed. Moreover, the comparison of solar TH regeneration method and solar electrodialysis regeneration method is discussed. The results showed that compared to the solar thermal regeneration system, the solar electrodialysis regeneration system is more energy-efficient but expensive. [Copyright &y& Elsevier]

Abstract: Demand response has proven to be a useful mechanism that produces important benefits for both the customer and the power system. In the context of an increasingly competitive electricity market, where prices are constantly rising and the presence of renewable energy resources is gaining prominence, this paper analyzes the flexibility potential of customers in the meat industry, based on the management of the most energy consuming process in this type of segment: cooling production and distribution. The effectiveness of the proposed actions has been successfully tested and validated in an active factory that produces cured ham in Spain, where savings of about 5% in the total annual cost of electricity have been assessed, together with power reductions in the range of 50% of the total peak demand of the studied facilities. Such results demonstrate the efficacy of these techniques, and they open the door to an innovative perspective on the evaluation of flexibility among customers which are traditionally considered rigid, providing a novel approach to the management of customer infrastructures in order to exploit their flexibility in electricity markets. [Copyright &y& Elsevier]

Abstract: Numerical simulations are essential to the understanding of the long-term geological storage of CO2. Physical modelling of geological storage of CO2 has been based on Darcy’s law, together with the equations of conservation of mass and energy. Modelling and simulations can be used to predict where CO2 is likely to flow, to interpret the volume and spatial distribution of CO2 under storage conditions, and to optimise injection operations. The state of the art of physical modelling and numerical simulation of CO2 dispersion is briefly reviewed in this paper, which calls for more accurate and more efficient modelling approaches. A systematic evaluation of the numerical methods used and a comparison between the streamline based methods and the grid based methods would be valuable. Multi-scale modelling may prove to be of great value in predicting the long-term geological storage of CO2, while highly accurate numerical methods such as high-order schemes may be employed in numerical simulations of CO2 dispersion for local transport calculations. [Copyright &y& Elsevier]

Abstract: The purpose of this paper is to investigate the reasons for ever growing energy consumption in buildings and to give enhanced supervision strategies for reduction of building energy consumption compared to regular ones. A case study of Ningbo city was used to make a detail analysis. Several factors were determined as the reasons for ever growing building energy consumption including climate change, household electricity load increase, the growth of real estate, fast-growing household electrical appliances, high energy consumption in existing buildings, changes in industrial structure and the lack of enhanced government supervision. Then the discussion of suitable countermeasures shows that only enhanced supervision strategies are currently applicable. Finally, it is concluded that enhanced government supervision strategies, including the establishment of a strict control system for new built buildings through information integration and encryption, establishing an energy efficiency supervision system of large-scale public building and a carrot-and-stick approach with added expert checklist for the building application of renewable energy, showed great advantages in promoting building energy efficiency in Ningbo, compared with other cities. These supervision strategies are applicable in other cities as they are in the similar situations in the enforcement of building energy efficiency. [Copyright &y& Elsevier]

Abstract: The purpose of this paper is to identify the relations between transportation energy consumption and its impacted factors. We first analyze the current status of transportation energy consumption in China. Then, the logarithmic mean Divisia index (LMDI) technique is used to find the nature of the factors those influence the changes in transportation energy consumption. We find that: (1) In 2006, the transportation energy consumption increased by 7.63 times against that in 1980. (2) Up to 2006, the oil consumed by transportation accounted for 49.6% of that in the whole country, which almost equaled to the net oil import. (3) In the light of the increasing energy consumption intensity, the energy-utilization effectiveness of transportation sector has been declining gradually. (4) The transportation activity effect is the most important contributor to increase energy consumption in the transportation sector and the energy intensity effect plays the dominant role in decreasing energy consumption. [Copyright &y& Elsevier]

Abstract: Along with high-speed economic development and increasing energy consumption, the Chinese Government faces a growing pressure to maintain the balance between energy supply and demand. In 2009, China has become both the largest energy consumer and CO2 emitting country in the world. In this case, the inappropriate energy consumption structure should be changed. As an alternative, a suitable infrastructure for the implementation of renewable energy may serve as a long-term sustainable solution. The perspective of a 100% renewable energy system has been analyzed and discussed in some countries previously. In this process, assessment of domestic renewable energy sources is the first step. Then appropriate methodologies are needed to perform energy system analyses involving the integration of more sustainable strategies. Denmark may serve as an example of how sustainable strategies can be implemented. The Danish system has demonstrated the possibility of converting into a 100% renewable energy system. This paper discusses the perspective of renewable energy in China firstly, and then analyses whether it is suitable to adopt similar methodologies applied in other countries as China approaches a renewable energy system. The conclusion is that China’s domestic renewable energy sources are abundant and show the possibility to cover future energy demand; the methodologies used to analyse a 100% renewable energy system are applicable in China. Therefore, proposing an analysis of a 100% renewable energy system in China is not unreasonable. [ABSTRACT FROM AUTHOR]

Abstract: As a renewable energy utilization system, the electric-driven seawater source heat pump district heating system is gaining popularity in some coastal areas. However, under what conditions can the system achieve its energy-saving effect and how to evaluate its energy-saving potential are not clear in practice. In this paper, an expression of the critical COP value of the heat pump unit for energy-saving (COP h,c ) is derived through the comparison of the system and the conventional boiler house district heating system in the energy consumption respect. On the other hand, the actual COP values of the heat pump unit (COP h,a ) are calculated by an experimental data regression model on the basis of the manufacturer''s dataset. The comparison of the values of COP h,c and COP h,a makes the energy-saving judgment of an electric-driven seawater source heat pump district heating system and its energy-saving potential, if it has, readily available. It was found that both the heating district radius and the natural conditions of the seawater are the most important factors that determine the energy efficiency of the system. And through comparison, it was also found that the type of the fuel of the boiler has significant impact on the crucial index value of COP h,c . [Copyright &y& Elsevier]

Abstract: This paper reports an experimental and simulation study of application of radiant cooling using natural air for ventilation under hot and humid climate of Thailand. To avoid condensation of moisture on the cooling panel, the temperature of water supplied to the panel was limited to 24°C. This led to the expectation that the low heat reception capacity of the panel would limit its use only to situations when loads were low. Experiments were conducted in an experimental room over the hot and dry period of March, the humid period of May, and the cool period of December. The results generally confirm the good potential for application of radiant cooling. However, the room was served by radiant panels with a total area of 7.5m2. Its capacity was grossly inadequate during the hot period, even for night time application only. A special configuration was devised to achieve thermal comfort for the area served by the panel. The well-known TRNSYS program was used to simulate the use of cooling panels and conventional air-conditioning in the experimental room. Simulation results match experimental results very well. Using comfort criterion adopted by ASHRAE and International Standards Organization, results from experiments and simulation show that thermal comfort could be obtained with application of radiant cooling. [Copyright &y& Elsevier]