• Energy Research

A novel methodology is proposed in this study to examine the stability of ecological industry chain network based on entropy theory. This methodology is developed according to the associated dissipative structure characteristics, i.e., complexity, openness, and nonlinear. As defined in the methodology, network organization is the object while the main focus is the identification of core enterprises and core industry chains. It is proposed that the chain network should be established around the core enterprise while supplementation to the core industry chain helps to improve system stability, which is verified quantitatively. Relational entropy model can be used to identify core enterprise and core eco-industry chain. It could determine the core of the network organization and core eco-industry chain through the link form and direction of node enterprises. Similarly, the conductive mechanism of different node enterprises can be examined quantitatively despite the absence of key data. Structural entropy model can be employed to solve the problem of order degree for network organization. Results showed that the stability of the entire system could be enhanced by the supplemented chain around the core enterprise in eco-industry chain network organization. As a result, the sustainability of the entire system could be further improved.

AbstractThere has been growing awareness and demand for construction enterprises’ transition toward sustainability with an aim to maximize the economic, social, and environmental values of construc...

Purpose– The purpose of this paper is to explore the barriers preventing investment in the re-use of low-grade multi-storey building stock in order to identify attributes that determine whether an existing building is suitable for retrofitting.Design/methodology/approach– Semi-structured interviews were undertaken with key industry practitioners to investigate existing practices and barriers facing low-grade building retrofits and what “ideal” multi-storey building features represent a successful investment opportunity.Findings– The findings showed that tenant commitment is necessary before any project goes ahead and that there exist many barriers influencing the investment decision. These include: high levels of asbestos found in existing buildings; changes in the National Construction Code necessitating enhanced fire safety and disability access; heritage listing; lack of awareness; overestimation of costs involved on simple and effective energy efficiency upgrades and change in tenant demands towards modern and efficient open plan offices. Many low-grade structures are privately owned inherited assets where the owners lack the expertise and capital to undertake retrofitting effectively.Research limitations/implications– The study is focused on the Adelaide CBD in South Australia but the findings are relevant to other Australian cities.Practical implications– There is room in the market for more positive and influential schemes such as the Green Building Fund that encourage more energy efficiency upgrading of these buildings.Social implications– The greater occurrence of retrofitting and re-use of older buildings, rather than demolition and rebuilding, has advantages with regard to reducing the impact of buildings on the environment and promoting sustainability.Originality/value– The research has indicated certain features of older buildings which render them as suitable candidates for retrofitting and refurbishment.

China is facing a number of energy related challenges including a shortage of electricity supply, depletion of fossil fuels and environmental pollution. These challenges make it important to develop renewable energy resources. As per other renewable energy industries, the biomass power industry is facing a series of opportunities and challenges. Utilizing Michael Porter's Five Forces Model theory for analyzing the competitive environment and the competitive situation of an industry, this paper establishes a Five Forces Model for assessing the competitiveness of China's biomass power industry. Inputs for this model include semi-structured interviews with biomass power generation enterprises and a critical analysis of the national policy framework along with relevant literature and official statistics. Five major stakeholders of China's biomass power industry, namely competitors, suppliers, buyers, potential competitors, and substitutes are assessed to determine their influence on the biomass power generation industry. This assessment highlighted the current status, existing issues and future prospects of the biomass power industry. Similarly, it provides assistance to develop procurement strategies for the sustainable development of the industry.

Abstract Associated with the continuing increase of construction activities such as infrastructure projects, commercial buildings, and housing programs, China has been experiencing a rapid increase of construction and demolition (CD and the landfill space demands were estimated to range from 7504 million m3 (the worst scenario) to 706 million m3 (the most optimistic scenario) accordingly. Consequently, increasing the recycling rate and reducing landfill rate of C&D waste could not only improve the potential recycling economic values, but also dramatically reduce land use and potential environmental impacts.

The traditional tie-line generation schedule is entirely based on the electricity transaction, hence it is independent of the generation schedule of local unit, and couldn't be changed by the load. These cause difficulties in resource allocation and safe and stable operation of power grid. Thus, this paper builds three optimal dispatch modes that are suitable for different scenes, whose objective functions are the maximization of grid safety margin, target tie line's absorption capacity and local wind power's absorption capacity. Based on this, the warning strategy models which are aimed at the possible safety problem during tie line connecting to the grid are proposed. At last, a case study based on practical data of a certain power grid is given to show that the models and the methods in this paper are validity and applicability.

Abstract Concentrating solar technology for building facade has attracted a growing level of attention due to its complex structure and dynamic optical properties. In the study presented in this paper, a new concentrating module using Fresnel lens as a concentrator has been designed to be integrated into a building curtain wall while a new connection control structure has been designed using joint bearings as the center fulcrum. The overall optical efficiency of the modules under the vertical incidence of solar radiation and maximum allowable deviation (1° deviation) is 78.68% and 76.86%, respectively. When the deviation exceeds the maximum allowable value, the amount of radiation obtained on the receiver decreases rapidly. The indoor daylight distribution with the integrated concentrating array is examined in this study under typical sunny and cloudy conditions of winter solstice, summer solstice and spring equinox in Tianjin, China. The results show that, during sunny days, the amount of solar radiation received on the floor surface behind the modules will decrease when the concentrating array is in a working state. However, the amount of solar radiation is still higher than in the area without direct sunlight. When the concentrating array is in a non-working state, the amount of radiation received by the floor surface is greater than that of working state, but less than that of without the integrated concentrating array. With the increase of solar altitude, the overall transmittance of the integrated concentrating array will decline. In cloudy conditions, the integrated concentrating array has less impact on the indoor daylight.

Abstract A large amount of demolition waste was generated due to the rapid urbanization. Prior to designing corresponding management measures, it is imperative to understand the amount, composition, and flows of the generated waste. This study proposes a novel approach to quantifying the demolition waste from generation to final disposal and, consequently, formulates corresponding strategies to managing the demolition waste, by using spatial and temporal dimensions in the Geographic information system. Specifically, a GIS-based model is proposed and consequently applied to a case study. Results show that over 135 million tons of demolition waste will be generated in the Nan Shan District between 2015 and 2060, and the recycling potential is valued at $ 6072 million under the optimistic scenario. By contrast, under the worst-case scenario, over 54 million m3 of land area which equals to approximate $ 218 billion could be needed for landfill. Compared to the worst-case scenario, the optimum scenario would reduce the amount of waste to be disposed in landfills by 80% and increase the value of recycling by 65%. The results revealed that, as a rapidly developing city, Shenzhen would likely experience the peak in the generation of demolition waste. Therefore, it is imperative to improve the recycling rate as it helps to raise the potential economic benefits and to reduce the landfill demand. This research is innovative in terms of the systemization, visual representation and analysis of quantifying the demolition waste flows via a novel method. The findings about the generation trends, economic values and environmental effects provide valuable information for the future waste management exercises of various stakeholders such as government, industry and academy.

Abstract Associated with the rapid economic growth, last decades have witnessed significant increases of both energy production and energy consumption in China. It is also recognized that the air pollutants emissions brought by excessive fossil energy consumptions have caused serious environmental problems. It is imperative to save energy and reduce emissions in China. As an innovative market mechanism, Energy Performance Contracting (EPC) can effectively reduce the energy consumption. China has released a series of laws, polices, regulations, and plans that include EPC related contents. Due to the massive demand as well as the facilitation efforts from the governments, EPC has developed rapidly in China. For instance, the number of employees, the aggregate investment, and the total output value of energy service companies increased by 31.8 times, 56 times and 73.2 times between 2005 and 2013. The evolution of policy system of EPC in China is examined in this study. The results show that legal protection, policy guidance and fiscal incentives are main measures to promote the development of EPC. These policies showcase China's efforts on achieving energy conservation, enhancing energy efficiency and improving environmental performance by encouraging the implementation of EPC. However, the analysis also reveals some existing issues. Further development of EPC depends on a number of factors such as a complete legal security system, a mature market mechanism, flexible economic incentives and the specific development plan for EPC. The experiences gained in China are helpful for promoting the development of EPC industry, especially in the developing countries.