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1.
China is facing a number of energy-related challenges such as shortage of electricity supply and environmental pollution. The Government recognized the important role the renewable energy plays in the power generation structure. As a result, a series of supporting policies, laws and regulations have been issued to boost the renewable energies in China. This paper provides a critical analysis of the policy framework for the renewable energy in China and its impacts on the power generation structure. The relevant policy documents, including the most recent government work report delivered by Premier Wen Jia-bao during the Third Session of the 11th National People’s Congress (NPC) in March 2010 are analyzed. The patterns of renewable energy developments are found strongly correlated with the promulgation of relevant policies.  相似文献   

2.
The Energy Tower concept is a renewable energy source suitable for dry and hot climates. It consists in cooling air by spraying water at the top of a tower approximately 1000 m high and thus creating a downdraft with a velocity of approximately 15 m/s. At the bottom of the tower the air goes through turbines and is subsequently exhausted through diffusers to the environment. In this work the influence of heat transfer from the droplets to the air is analyzed, the effect of coalescence being described using the O’Rourque model. It is shown that coalescence is substantial inside the tower and results in the droplets being an order of magnitude larger at the tower bottom and that there is a slight adverse effect on the energy performance, since evaporation from larger droplets is substantially less than from smaller droplets. In the case however that the water spray is a saline solution – which is the only possibility in view of unsalted water being as scarce a resource as energy – it makes it possible to keep the deposited salt inside the tower and the diffuser and in the immediate vicinity of the construction.  相似文献   

3.
This paper examines the possibility of asymmetric transmission of CO2 prices to electricity futures prices in the second phase of the European Emission Trading Scheme. We would like to assess whether output prices tend to respond more quickly to input price increases than decreases: this phenomenon is known as “rockets and feathers” in the literature. Compared to Zachmann and von Hirschhausen (2008), who carried out a similar analysis for Germany in the first phase of the Emission Trading Scheme with data from 2005 to 2006, our study spans a longer timeframe (July 2007–June 2010), with a presumably more mature permit market, and includes three additional European countries (France, Belgium and the Netherlands). Results do not provide empirical evidence of statistically significant differences in the response of power prices to positive and negative shocks in CO2 allowance and fuel markets.  相似文献   

4.
The ongoing transformation of the European energy system comes along with new challenges, notably increasing amounts of power generation from intermittent sources like wind and solar. How current objectives for emission reduction can be reached in the future and what the future power system will look like is, however, not fully clear. In particular, power plant investments in the long run and power plant dispatch in the short run are subject to considerable uncertainty. Therefore an approach is presented which allows electricity market development to be assessed in the presence of stochastic power feed-in and endogenous investments in power plants and renewable energies. To illustrate the range of possible future developments, five scenarios for the European electricity system up to 2050 are investigated. Both generation investments and dispatch as well as utilization of transmission lines are optimized for these scenarios and additional sensitivity analyses are carried out.  相似文献   

5.
Increasing energy efficiency is discussed as an effective way to protect the climate, even though this is frequently associated with additional (investment) costs when compared to standard technologies. However, the investment costs of emerging energy-efficient technologies can be reduced by economies of scale and experience curve effects. This also brings about higher market penetration by lowering market barriers. Experience curves have already been analyzed in detail for renewable energy technologies, but are not as well documented for energy-efficient technologies despite their significance for energy and climate policy decisions. This work provides empirical evidence for effects of economies of scale and experience on the costs of energy-efficient electric motors. We apply a new methodology to the estimation of learning effects that is particularly promising for energy-efficient technologies where the very low data availability did not allow calculations of learning rates so far. Energy-efficient electric motors are a highly relevant energy technology that is responsible for about 55% of German electricity consumption. The analysis consists of three main steps. First, the calculation of composite price indices based on gross value added statistics for Germany which show the changes in cost components of electric motors over the period 1995 to 2006; second, an estimation of the corresponding learning rate which is, in a third step, compared with learning rates observed for other energy-efficient technologies in a literature review. Due to restrictions of data availability, it was not possible to calculate a learning rate for the differential costs of energy-efficient motors compared to standard motors. Still, we estimated a learning rate of 9% for “Eff2” motors in a period when they penetrated the market and replaced the less efficient “Eff3” motors. Furthermore, we showed the contribution of different effects to these cost reductions, like a reduction of material use per motor produced by 15% and an improvement of labor productivity of 43%.  相似文献   

6.
In this paper, a newly developed assessment platform Odyssey is introduced. This platform is dedicated to perform comprehensive techno-economic assessments of energy systems comprising renewable energy sources and energy storage units. The major strengths of this platform are described and it is then illustrated on an application example with the objective to provide elements of validation of the platform. This application case is related to the electrical energy supply of a weather station by the mean of a PV-hydrogen hybrid energy system combining PV modules and a hydrogen chain. Experimental results obtained on the fuel cell and electrolyser systems are confronted to simulation results.  相似文献   

7.
Increased shares of Renewable Energy Sources (RES) to fulfill ambitious European policy targets, mothballing or decommissioning of existing units, and absent investments lead to concerns about the system and market adequacy. To restore market adequacy, capacity mechanisms (CMs) are widely discussed and implemented in various types. They are intended to provide sufficient and clearly perceivable long-term price signals for available capacity. As integral part of the market, CMs interact with the other markets. Markets like day-ahead markets are used to trade energy. Imbalance markets or reserve requirements are examples for markets for flexibility. Among others, green certificates are in place to value emission-neutral injection from RES. Resulting altered prices and shifting remuneration have effects on all generation technologies. CMs may affect participating technologies by imposing a capacity demand. A resulting change in the generation mix may also have an impact on non-participating technologies. Two gaps can be identified in the discussion and modeling of CMs in the literature. First, proposed game-theoretic equilibrium models fall short in representing the distinctive features of different types of CMs. Second, most models incorporating CMs found in the literature only focus on the interaction with the energy-based market. Valid assessments of CM need to consider the interaction of remuneration for available capacity and flexibility, and the indirect interaction with the remuneration for emission-neutral RES. Two formulations of a game-theoretic market equilibrium model are proposed which represent specific CMs with its distinctive features, in particular a market-wide centralized capacity market (cCM) and targeted strategic reserves (SRs). Moreover, the equilibrium models explicitly combine the CMs with markets for flexibility and indirect with remuneration for RES. We contribute to the discussion of CMs by quantifying the interactions and shifting shares of remuneration. Based on the interaction between CMs and remuneration for emission-neutral injection, the effect of CMs on non-participating RES is described. We conclude based on the case study results that targeted mechanisms, like SRs, implemented with the single purpose of ensuring availability introduce large inefficiencies in the system by missing on the interaction between availability and flexibility. In contrast, a market-wide cCM provides a beneficial outcome for all technologies. At the same time, it yields a sufficient high reserve margin at lowest cost. It provides clear signals for the different values of energy-output, flexibility, availability and emission-neutral injection.  相似文献   

8.
This paper presents an analysis of the feasibility of implementing biomass power plants, through thermoelectric power generation, and adding such plants to the electric system of the local electric utility by means of independent power production. Economic, regulatory, and market issues are also addressed.The biomass being considered is produced by the lumber sector, since that is one of the industrial sectors generating the largest amount of residues in a concentrated manner in the region under study, and also considering the fact that the disposal of such residues is currently difficult for the lumber companies.The locations with the largest production of residues, as well as the size of potential plants, are identified, the generation costs of the plants calculated, and the feasibility for implementing the plants is evaluated considering the market and the regulation of the Brazilian electric power sector.  相似文献   

9.
This paper contrasts the potential increase in gas-fired power generation in the UK in the period to 2020 with the ambitious decarbonisation goals set forth for this sector. An increase in Combined Cycle Gas Turbine (CCGT) capacity, in particular, only represents a threat to long-term decarbonisation if some ‘lock-in’ exists. It is against this background, and in the interest of challenging the perception of no significant lock-in to gas-fired generation, that this paper identifies investment lock-in as phenomenon of relevance to policy-makers. The paper determines both direct and indirect ways in which investment in significant new CCGT capacity could negatively impact on the likelihood of meeting decarbonisation goals through ‘locking-in’ the existing technological system. It also identifies that the technical lifetime, and not just the capital repayment period, of CCGT assets is relevant in understanding the strength of the lock-in. Finally, a regulatory structure that aligns with the long-term targets in place is identified as providing a clear signal for investors and asset owners that may reduce the risk of ‘investment lock-in’.  相似文献   

10.
This paper compares different backup power systems for uninterruptible emergency power supply (UPS) in the kW-power range. The cost structure of direct methanol fuel cell systems (DMFCs) is deduced from a DMFC system developed for the replacement of batteries in small fork-lift trucks. The setup for new DMFC backup power systems will be further simplified and those systems will be operated without expensive sensors necessary for laboratory testing. A detailed cost structure of such systems is shown, and in a cost comparison the competitiveness to other existing UPS technologies is indicated.In spite of reduced sensor systems the efficient and secure operation of the system must be guaranteed. The demanded durability in case of UPS is ten years in discontinuous operation. To achieve the long term stability the right treatment of the stack during standby was identified by tests on single cells as well as on short stacks. A number of different standby procedures have been tested in order to identify how the MEAs must be treated in order to avoid premature degradation during standby.  相似文献   

11.
The European Union set binding targets for the reduction of greenhouse gases (GHG) and the share of renewable energy (RE) in final energy consumption by 2020. The European Council agreed to continue with this strategy through to 2030 by setting a RE target of 27% in addition to a GHG reduction target of 40%. We provide a detailed sectoral impact assessment by analyzing the implications for the electricity sector in terms of economic costs and the regional distribution of investments and shares of electricity generated from renewable energy sources (RES-E). According to the Impact Analysis by the European Commission the 27% RE target corresponds to a RES-E share of 49%. Our model-based sensitivity analysis on underlying technological and institutional assumptions shows that the cost-effective RES-E share varies between 43% and 56%. Secondly, we quantify the economic costs of these variants and those which would be incurred with higher shares. The long-term additional costs for higher RES-E shares would be less than 1% of total system costs. The third aspect relates to the regional distribution of EU-wide efforts for upscaling renewables. We point out that delivering high RES-E shares in a cost-effective manner involves considerably different efforts by the Member States.  相似文献   

12.
《Energy Conversion and Management》2004,45(11-12):1671-1679
An experimental study was performed to investigate the effect of using different types of sun tracking systems on the voltage–current characteristics and electrical power generation at the output of flat plate photovoltaics (FPPV). Four electromechanical sun tracking systems, two axes, one axis vertical, one axis east–west and one axis north–south, were designed and constructed for the purpose of investigating the effect of tracking on the electrical values, current, voltage and power, according to the different loads (variable resistance). The above mentioned variables were measured at the output of the FPPV and compared with those on a fixed surface. The results indicated that the volt–ampere characteristics on the tracking surfaces were significantly greater than that on a fixed surface. There were increases of electrical power gain up to 43.87%, 37.53%, 34.43% and 15.69% for the two axes, east–west, vertical and north–south tracking, respectively, as compared with the fixed surface inclined 32° to the south in Amman, Jordan.  相似文献   

13.
This study presents empirical insight into willingness to pay (WTP) for microgeneration technologies and the relative influence of subjective consumer perceptions. First, we apply a double-bounded contingent valuation method to elicit Irish home owners' WTP for micro wind turbines, wood pellet boilers, solar panels and solar water heaters. Utilizing findings from the adoption of innovation literature, in a second step we assess the influence of antecedents on WTP for each of the four technologies, including (1) home owners' perception of product characteristics, (2) normative influences and (3) sociodemographic characteristics. Our results show that WTP varies significantly among the four technologies. More importantly, however, home owners hold different beliefs about the respective technologies, which significantly influence their WTP. The results provide valuable information for marketers and policy makers aiming to promote microgeneration technologies more effectively in consumer markets.  相似文献   

14.
Major re-thinking is required on the conventional pulverized fuel conversion route of power generation wherein the ash and mineral burden in coals is transported through the entire flow passage of the boiler. For high-ash fuels, this has to be contained and the boiler must be clear of all mineral matter. The two independent clean coal candidate technologies for efficiency enhancement and emission controls – ultra-supercritical cycle (USC) and integrated gasification with combined cycle (IGCC) – both have limitations in adaptation to high-ash coals. While the USC is limited by the steam temperature up to 600°C (commercial scale) (700°C pilot scale) and boiler tube failure risks, IGCC is limited to high-quality fuels like diesel, naphtha, etc. (commercial scale) and high-grade coals (pre-commercial scale). The hybridization of the two technologies in their current form (ultra-supercritical cycle with gasification conversion) and carbon capture and storage (CCS) together with solar energy (solar thermal and solar photovoltaic) integration presents possibilities for immediate application to low-grade sub-bituminous coals to achieve the clean technology goals. The energy efficiency of the hybrid system is around 44.45%, which is of the order of the USC with pulverized coal combustion. But the predominant benefits of a clean operation override. The benefits are reduction in CO2 generation from 0.86 to 0.70 kg/kWh and reduction in ash expelled from 0.20–0.24 to 0.12–0.18 kg/kWh besides elimination of dispersion of ash around the power station and facilitating CCS.  相似文献   

15.
Experiments made with a model helical chipper have shown that the infeed angle has a huge impact on chip quality parameters. Furthermore, it could be pointed out that the self feeding mechanism of the helical chipper was impeded with larger infeed angles and finally failed. This situation led to the hypothesis that the infeed angle must have an impact on power requirement during chipping. In the present investigation this conclusion was tested. Standardized preformed test rods were chipped with a helical chipper at seven different infeed angles while torque, rotational speed and chipping time were recorded. The experimentation was done using poplar wood with different moisture content. Based on the measurements power requirement and energy consumed was calculated for each test series. The results of the experiments show that power requirement and energy consumed are decreasing with increasing infeed angle. The results seem to be extraordinary since increasing infeed angles lead to decreasing chip sizes being produced. Based on theoretical deliberations and experimental data it can be assumed that besides the anisotropic character of wood geometrical settings of helical chipping could be a reason for the experimental findings. But, because the chipping time is also dependent on the infeed angle there still must be other reasons concerning the occurring forces during helical chipping, too. For this reason there is a need to have a closer look onto the different forces occurring during helical chipping. Against this background the Discrete Element Method (DEM) could be a simulation method for future research.  相似文献   

16.
The goal of this paper is to analyse the impact of the implementation of a certification system on the management system (costs) of and the availability of land (quantity) for bioenergy production. Twelve socio-economic areas of concern (food supply, child labour, (minimum) wages, employment, health care and education) and environmental areas of concern (soil erosion, depletion of fresh water resources, nutrient losses and soil nutrient depletion, pollution from chemicals and biodiversity) are included. Since there is no generally accepted definition of sustainability, a loose and strict set of criteria are defined. Short rotation coppice (SRC) production systems in Ukraine and South East Brazil in 2015 are taken as case studies. The results indicate that it seems feasible to produce biomass for energy purposes at reasonable cost levels and meeting strict sustainability criteria at the same time. The loose set of criteria has no impact on the costs of energy crop production, which are calculated to be 1.7  GJ?1 in Brazil and 2.1  GJ?1 in Ukraine. The strict set of criteria results in an increase of the costs of energy crop production by 42 % in Brazil and 14 % in Ukraine. In general, compliance with strict socio-economic criteria has a limited impact on the costs, because SRC is relatively labour extensive. Strict environmental criteria likely have a larger impact.  相似文献   

17.
The present study combines methylcyclohexane dehydrogenation and toluene hydrogenation systems to produce steam for power generation. Methylcyclohexane dehydrogenation requires heat input, which has been accomplished using heat, released from toluene hydrogenation system, and heat exchange with steam, produced from the steam generator. The integration of these systems results in the generation of 5 MW electricity, which is used to run the electrolysis unit. The overall process does not require an extra source of energy, decreasing the external utility requirement. Both the systems have been investigated against various catalysts for the selection of best catalyst, thus enhancing overall process efficiency. The study has been carried out using Aspen HYSYS v 9. Aspen Energy Analyzer v 9 has been used to do the energy analysis of the system. Overall plant costing has been carried out using Aspen Economic Analyzer v 9.  相似文献   

18.
As an immanent necessity to reduce global greenhouse gas emissions, the energy transition poses a major challenge for the next 30 years, as it includes a cross-sectoral increase of fluctuating renewable energy production, grid extension to meet regional electricity supply and demand as well as an increase of energy storage capacity. Within the power-to-gas concept, hydrogen is considered as one of the most promising solutions.The paper presents a scenario-based bottom-up approach to analyse the hydrogen supply chain to substitute diesel with fuel cell buses in the Rhine-Main area in central Germany for the year 2025. The analysis is based on field data derived from the 6 MW power-to-gas plant “Energiepark Mainz” and the bus demonstration project “H2-Bus Rhein-Main”. The system is modelled to run simulations on varying demand scenarios. The outcome is minimised hydrogen production costs derived from the optimal scheduling of a power-to-gas plant in terms of the demand. The assessment includes the energy procurement for hydrogen production, different hydrogen delivery options and spatial analysis of potential power-to-gas locations.  相似文献   

19.
In many regions, international power system interconnections provide economic, energy-security, environmental, and technical benefits. In contrast, such interconnections remain scarce in Northeast Asia. In 2016, after approving a joint memorandum of understanding between major electric power companies from China, Japan, South Korea, and Russia, related initiatives regained momentum in the region. Nevertheless, the corresponding developments in Japan remain limited, mainly owing to the lack of involvement of Japanese electric power companies. This study represents a pioneering attempt to provide an economic assessment based on power exchange prices of a power system interconnection between Japan and South Korea regarding the competitiveness of electric power companies in terms of competitive business segments and strategic consequences. We found that although the position of Japanese generators may slightly deteriorate, that of the supply segment would substantially improve, thus suggesting that more opportunities than threats are derived from the interconnection. This promising outcome may foster the adoption of an interconnection with South Korea considering the positive economic and business perspectives in Japan. Furthermore, realizing the interconnection may improve the energy security and air quality in the region.  相似文献   

20.
With the global sustainability transition in energy, hydrogen fuel cell (HFC) applications currently have important niche roles to play across several industrial sectors. Theorists examining this innovative activity have identified key socio-technical factors affecting the nature and pace of change. One functional approach to innovation, Technology-Specific Innovation Systems (TSISs), places national HFC Technological Innovation Systems (TISs) within a framework of a global HFC TSIS. This analytical approach suggests that HFC innovation can start anywhere in space. However, in a case study of HFC innovation and diffusion in the UK covering sixty years’ activity, this theoretical assumption is challenged. Event history analysis and interviews using a neofunctionalist TSIS approach suggest that positive feedback was on the brink of occurring in the UK HFC TIS by 2012. When additional organisational and spatial indicators are added, the evidence on the ground does not support the aspatial assumptions that underlie TIS heuristic thinking. Rather, it suggested that type of investment funding and spatial location can influence HFC innovation. In this context, the implications for HFC policy in the UK are discussed.  相似文献   

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