Different sources of rural household energy consumption and influencing factors in Dazu,China

Rural household energy consumption is an important component of national energy consumption. This paper explores the rural household energy consumption status and influencing factors on different sources of rural household energy consumption in western China. Using data from a survey of 240 households conducted in 2017, this study finds that rural households’ energy consumption structure in the study area is a combination of traditional biomass energy and commercial energy sources. Fuelwood is the most commonly used fuel in the study area, while modern energy sources only occupy a low proportion. Rural household energy consumption is influenced by various factors. Individual perceptions of climate change, social trust and networks, and households’ socio-economic and demographic factors (gender, age, education, income per capita, household size, household location, and number of household appliances) are identified as having significant effects on rural households’ consumption of biomass and commercial energies. The research results provide implications for policy makers to formulate related rural energy policies to improve the rural energy consumption structure and future energy policy design in China and other developing countries.

     

污水处理厂的能源与资源回收方式及其碳排放核算：以芬兰Kakolanmäki污水处理厂为例

探索切实可行的资源与能源回收方案、实现污水处理的碳中和运行,是污水处理领域的重要发展方向。北欧国家一些污水处理厂已凭借污泥厌氧消化产甲烷(CH₄)并热电联产(CHP)、以及余温热能利用等技术实现了能源的回收利用。以芬兰Kakolanmäki污水处理厂为例,结合该厂的污水处理工艺流程分析其能源回收方式,并运用碳足迹模型核算了其污水处理工艺与能源回收环节的碳减排量,以确定其整个运行中的碳足迹。分析结果表明,该厂污水处理工艺不仅可以满足严格的出水水质排放标准,还可通过回收出水余温热能等方式实现能源中和与碳中和运行,并向社会供热。其中,该厂的总回收能量(电能+热能)大于其自身能耗的6.4倍。出水余温热能回收潜力最大,约占全部可回收能量的90%;厌氧消化并热电联产所回收的化学能不足10%。回收能源不仅使该厂实现碳中和(碳中和率333%)运行,而且剩余碳汇(以CO₂当量计)达24 931 t ·a⁻¹。该厂的实践表明,污水处理实现碳中和运行的关键在于重视出水中大量的余温热能回收。芬兰Kakolanmäki污水处理厂的案例可为国内污水处理厂探索高效能源利用、并实现碳中和运行提供参考。     

Panel Discussion on Energy Efficiency

The session on energy efficiency had no formal presentations and was organized as a panel discussion with four panelists. It was concluded that energy efficiency and saving measures on the short term is the most effective way to contribute to a sustainable energy system. Measures to improve and encourage energy efficiency should be implemented at all levels; municipal/local, national and super-national. Prices can be an effective instrument but need to be combined with systemic level measures. The transport sector was identified as the one with largest near future potential for increased energy efficiency. Agriculture and food is also an area with very large energy consumption and large potential for increased energy efficiency. The global population issue is yet another relevant, challenging and complex issue. It was noted that energy audits for end users in business and society increase awareness and insights into what they pay for, and they are likely to promote actions to save energy. Many measures are believed to suffer from Jevin’s paradox, i.e., that more efficient use of energy just leads to more energy consumption somewhere else. Many examples were given, however, where this does not happen. Another point put forward was that measures to make the energy system more efficient do not only mean constraints and regulations but also create great opportunities for market actors and societies.     

废铅蓄电池回收的节能降碳案例分析

为了解我国废铅蓄电池回收过程的节能降碳现状,以典型废铅蓄电池回收工艺为研究对象,分析了废铅蓄电池回收过程的产品综合能耗和碳排放情况。结果表明,案例企业的单位产品综合能耗 (当量能耗) 为98.35 kgce·t⁻¹;天然气消耗是最大的能耗来源;铅膏熔炼工序是废铅蓄电池回收过程中产品综合能耗和碳排放量最大的工序;焦粉作为还原剂进入熔炼工序的排放是最主要的碳排放源。在燃料燃烧、能源作为原材料、净购入电力和热力方面,能耗和碳排放量核算是线性相关的,在上述方面寻求节能措施可使废铅蓄电池回收企业实现同时降碳。此外,碳酸盐引起的过程排放和耗能工质也会影响企业的节能降碳效果,建议在后续的核算指南中进行统一规定。本研究结果可为废铅蓄电池回收过程的节能降碳提供参考。     

Renewable energy and energy-saving initiatives in Greece: policy and experience

Energy policy is a key issue for economic and environmental policies. Indeed, energy is an indispensable element for economic development while, on the other hand, it causes severe environmental problems. In this context, a pressure for using renewable energy resources and for energy saving has emerged and expanded in recent years. As a result, energy policy is being reoriented under the new conditions. This paper examines this reorientation and its results in Greece where the bioclimatic conditions are in favour of renewable energy resources and energy-saving projects.     

Renewable Energy

The Energy Committee of the Royal Swedish Academy of Sciences has in a series of projects gathered information and knowledge on renewable energy from various sources, both within and outside the academic world. In this article, we synthesize and summarize some of the main points on renewable energy from the various Energy Committee projects and the Committee’s Energy 2050 symposium, regarding energy from water and wind, bioenergy, and solar energy. We further summarize the Energy Committee’s scenario estimates of future renewable energy contributions to the global energy system, and other presentations given at the Energy 2050 symposium. In general, international coordination and investment in energy research and development is crucial to enable future reliance on renewable energy sources with minimal fossil fuel use.     

The Energy for Growing and Maintaining Cities

Herein we develop a means to differentiate between the energy required to expand and the energy required to maintain the economies of cities. A nonlinear model is tested against historical data for two cities, Hong Kong and Singapore. A robust fit is obtained for Hong Kong, with energy for maintenance close to that for growth, while Singapore, with a weaker fit, is growth dominated. The findings suggest that decreases in either of the per unit maintenance or growth demands can simultaneously cause gross domestic product (GDP) and total energy use to increase. Furthermore, increasing maintenance demands can significantly limit growth in energy demand and GDP. Thus, the low maintenance demands for Hong Kong, and especially Singapore, imply that, all other things being equal, GDP and energy use of these cities will continue to grow, though Singapore’s higher energy use for growth means it will require more energy than Hong Kong.     

Burning Water: A Comparative Analysis of the Energy Return on Water Invested

While various energy-producing technologies have been analyzed to assess the amount of energy returned per unit of energy invested, this type of comprehensive and comparative approach has rarely been applied to other potentially limiting inputs such as water, land, and time. We assess the connection between water and energy production and conduct a comparative analysis for estimating the energy return on water invested (EROWI) for several renewable and non-renewable energy technologies using various Life Cycle Analyses. Our results suggest that the most water-efficient, fossil-based technologies have an EROWI one to two orders of magnitude greater than the most water-efficient biomass technologies, implying that the development of biomass energy technologies in scale sufficient to be a significant source of energy may produce or exacerbate water shortages around the globe and be limited by the availability of fresh water.     

The global contribution of energy consumption by product exports from China

This paper presents a model to analyze the mechanism of the global contribution of energy usage by product exports. The theoretical analysis is based on the perspective that contribution estimates should be in relatively smaller sectors in which the production characteristics could be considered, such as the productivity distribution for each sector. Then, we constructed a method to measure the global contribution of energy usage. The simple method to estimate the global contribution is the percentage of goods export volume compared to the GDP as a multiple of total energy consumption, but this method underestimates the global contribution because it ignores the structure of energy consumption and product export in China. According to our measurement method and based on the theoretical analysis, we calculated the global contribution of energy consumption only by industrial manufactured product exports in a smaller sector per industry or manufacturing sector. The results indicated that approximately 42% of the total energy usage in the whole economy for China in 2013 was contributed to foreign regions. Along with the primary products and service export in China, the global contribution of energy consumption for China in 2013 by export was larger than 42% of the total energy usage.     

Exploring the impact of transition in energy mix on the CO2 emissions from China’s power generation sector based on IDA and SDA

Environmental Science and Pollution Research - The energy transition from coal and oil to renewable energy, nuclear energy, and natural gas is a fundamental way for emission reduction of...     

Towards sustainable household energy use in the Netherlands

Households consume direct energy, using natural gas, heating oil, gasoline and electricity, and consume indirect energy, the energy related to the production of goods and the delivery of services for the households. Past trends and present-day household energy use (direct and indirect) are analysed and described. A comparison of these findings with objectives concerning ecological sustainability demonstrates that present-day household energy use is not sustainable. A scenario towards sustainable household energy use is designed containing far-reaching measures with regard to direct energy use. Scenario evaluation shows a substantial reduction of direct energy use; however, this is not enough to meet the sustainability objectives. Based on these results, the possibilities and the limitations are discussed to enable households to make their direct and indirect energy use sustainable on the long run.     

Subisokinetic Sampling Errors for Aircraft Turbine Engine Smoke Probes

The years 2012 and beyond seem likely to record major changes in energy use and power generation. The Japanese tsunami has resulted in large countries either scaling back or abolishing the future use of nuclear energy. The discovery of what seems like vast amounts of economically deliverable natural gas has many forecasting a rapid switch from coal- to gas-fired generating plants. On the other hand, environmentalists have strong objections to the production of natural gas and of petroleum by hydraulic fracturing from shale, or by extraction of heavy oil. They believe that global warming from the use of fossil fuels is now established beyond question. There has been rapid progress in the development of alternative energy supplies, particularly from on-shore and off-shore wind. Progress toward a viable future energy mix has been slowed by a U.S. energy policy that seems to many to be driven by politics. The author will review the history of power and energy to put all of the above in context and will look at possible future developments. He will propose what he believes to be an idealized energy policy that could result in an optimum system that would be arrived at democratically.

Implications The combustion energy sector is believed to be a dominant component of environmental pollution. A multitude of technologies support this sector and many have the potential to replace elements of this sector with low-polluting processes. This review covers a selection of energy production technologies that are important for the future. A historical perspective is provided to advance the general knowledge about these technologies as options for the world's increasing demand for energy. In addition, a decarbonization policy option for an energy fee is proposed as an alternative to carbon taxation or cap-and-trade approaches.     

Impact of environmental investment and resource endowment on regional energy efficiency: evidence from the Yangtze River Economic Belt,China

Environmental Science and Pollution Research - As a key economic resource, energy plays an important and strategic role in the national economy. Conserving energy and improving energy efficiency...     

污水处理行业实现碳中和的路径及其适用条件分析

节能降耗、厌氧消化产甲烷、工艺相关的能源利用等策略可有助于碳减排,但这些常规方法的潜力距碳中和目标仍有相当距离。国外诸多案例表明,污水余温热能利用技术是污水处理领域实现碳中和运行的可行方案。在总结污水处理领域碳减排策略的基础上,评价分析其对碳中和的贡献。通过对国内案例计算分析余温热能潜力并与有机 (COD) 能转化率进行比较发现,污水中蕴含的余温热能潜力为有机能的9倍。余温热能利用可使污水处理厂达到碳中和目标,还可将剩余热能 (约75%~85%) 向外以供热/制冷形式输出,或用于原位低温干化污泥,实现污水处理厂向“能源工厂”的转型。     

Review on phase change materials for solar energy storage applications

Environmental Science and Pollution Research - The energy storage application plays a vital role in the utilization of the solar energy technologies. There are various types of the energy storage...     

Energy return on investment: toward a consistent framework

Numerous technologies have been proposed as partial solutions to our declining fossil energy stocks. There is a significant need for consistent metrics to compare the desirability of different technologies. The ratio of energy produced to energy consumed by an energy production technology-known as the energy return on investment (EROI)-is an important first indicator of the potential benefits to society. However, EROI analysis lacks a consistent framework and has therefore yielded apparently conflicting results. In this article, we establish a theoretical framework for EROI analysis that encompasses the various methodologies extant in the literature. We establish variations of EROI analysis in two different dimensions based on the costs they include and their handling of nonenergy resources. We close by showing the implications of the different measures of EROI upon estimating the desirability of a technology as well as for estimating its ultimate net energy capacity.     

Household energy consumption in Switzerland

Households consume more energy embodied in goods and services than they consume with energy carriers. Thus, energy assessments need to address both direct consumption and indirect consumption via commodities. This paper first presents a conceptual framework for describing and analysing the direct and indirect energy use of households. The framework is based on material flux analysis and differentiates between four household activities feeding, housing, transporting and consuming. Secondly, Swiss data on household energy consumption are presented and discussed in the context of household size, technology and consumption behaviour. It is shown that these factors considerably shape per capita energy demand. The third part presents energy projections based on trend assumptions for demographic and technological developments for the next 30 years. When zero growth per capita in commodities consumption is assumed, overall energy demand will increase by about 5%, mainly due to strong increases in gasoline demand. When the growth rate of commodities consumption exceeds 0.3% per year, embodied energy demand will offset efficiency gains achieved by technological improvements in the economic and domestic sectors and will fuel overall energy growth.     

Biomass energy consumption and sustainable development: empirical evidence from Asian economies

Environmental Science and Pollution Research - Biomass energy is an important source of energy consumption. It is a renewable, abundant, and easily produced energy source. Its usage supports...     

太湖流域城镇污水处理厂能耗评价与分析

为分析太湖流域污水处理厂的能耗情况,以比能耗分析法为基础,结合多种统计学方法,探究了太湖流域污水处理厂能耗现状、水量比能耗、污染物削减量比能耗、能耗与日处理水量和耗氧污染物削减量之间的关系。结果表明：太湖流域污水处理厂2017年能耗均值为0.458 kWh·m⁻³,高于发达国家污水处理厂能耗平均值;太湖流域处理规模大于5×10⁴ m³·d⁻¹的污水处理厂水量比能耗基本稳定在0.33 kWh·m⁻³,而处理规模小于5×10⁴ m³·d⁻¹的污水处理厂水量比能耗波动较大;化学需氧量(COD)和氨氮(${\rm{NH}}_4^{+} $-N)削减量与污染物削减量比能耗之间均存在幂函数关系,在每个污染物出水浓度区间内,均呈现削减污染物量越多,污染物削减量比能耗越低的趋势;污水处理厂能耗与日处理水量和耗氧污染物削减量之间存在线性关系。因此,对污水处理厂的节能降耗须重点关注污染物削减量比能耗的降低。     

A research on conventional and modern algorithms for maximum power extraction from wind energy conversion system: a review

Environmental Science and Pollution Research - In the last few decades, wind energy has become a significant source of the renewable energy system, and it is essential to use wind energy for...