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1.
    
Renewable energy systems are essential in coming years to ensure an efficient energy supply while maintaining environmental protection. Despite having low environmental impacts during operation, other phases of the life cycle need to be accounted for. This study presents a geo‐located life cycle assessment of an emerging technology, namely, floating offshore wind farms. It is developed and applied to a pilot project in the Mediterranean Sea. The materials inventory is based on real data from suppliers and coupled to a parameterized model which exploits a geographic information system wind database to estimate electricity production. This multi‐criteria assessment identified the extraction and transformation of materials as the main contributor to environmental impacts such as climate change (70% of the total 22.3 g CO2 eq/kWh), water use (73% of 6.7 L/kWh), and air quality (76% of 25.2 mg PM2.5/kWh), mainly because of the floater's manufacture. The results corroborate the low environmental impact of this emerging technology compared to other energy sources. The electricity production estimates, based on geo‐located wind data, were found to be a critical component of the model that affects environmental performance. Sensitivity analyses highlighted the importance of the project's lifetime, which was the main parameter responsible for variations in the analyzed categories. Background uncertainties should be analyzed but may be reduced by focusing data collection on significant contributors. Geo‐located modeling proved to be an effective technique to account for geographical variability of renewable energy technologies and contribute to decision‐making processes leading to their development.  相似文献   

2.
    
According to previous studies, the life cycle energy intensity of an offshore wind farm (OWF) varies between 0.03 and 0.13 megawatt‐hours (MWh) of primary energy for each MWh of electricity generated. The variation in these life cycle energy intensity studies, after normalizing for capacity factor and life span, is significantly affected by OWF location because of geographical properties, namely, wind speed and water depth. To improve OWF siting, this study investigates how an OWF's distance from shore and geographical location impacts its environmental benefit. A process‐based life cycle assessment is conducted to compare 20 OWF siting scenarios in Michigan's Great Lakes for their cumulative fossil energy demand, global warming potential, and acidification potential. Each scenario (four lake locations at five offshore distances) has unique foundation, transmission, installation, and operational requirements based on site characteristics. The results demonstrate that the cumulative environmental burden from an OWF is most significantly affected by (1) water depth, (2) distance from shore, and (3) distance to power grid, in descending order of importance, if all other site‐relevant variables are held constant. The results also show that when OWFs are sited further offshore, the benefit of increased wind energy generation does not necessarily outweigh the increase in negative environmental impacts. This suggests that siting OWF nearer to shore may result in a better life cycle environmental performance. Finally, we demonstrate how much an OWF's environmental burdens can be reduced if the OWF system is either recycled, transported a shorter distance, or manufactured in a region with a high degree of renewable energy on the grid.  相似文献   

3.
    
Urban energy metabolism includes processes for exploiting, transforming, and consuming energy, as well as processes for recycling by‐products and wastes. Embodied energy is the energy consumed during all of these activities, both directly and indirectly. Multiregional input‐output (MRIO) analysis can calculate the energy consumption embodied in flows among sectors for multiple cities or regions. Our goal was to address a problem apparent in previous research, which was insufficient attention to indirect energy flows. We combined MRIO analysis with ecological network analysis to calculate the embodied energy consumption and the energy‐related carbon footprints of five sectors in three regions that comprise the Jing‐Jin‐Ji agglomeration, using data from 2002 and 2007. Our analysis traced metabolic processes of sectors from the perspective of final consumption. Based on the embodied energy analysis, we quantified the indirect energy consumption implied in exchanges of sectors and its distribution and identified the relationships formed through the indirect consumption to analyze the roles of providers and receivers in the system. Results showed that the embodied energy consumption for the Jing‐Jin‐Ji region increased from 2002 to 2007 as a result of increased energy consumption in Tianjin and Hebei. Overall, consumption of Beijing decreased likely attributable to the fact that government policies relocated industries during this time in anticipation of the Olympic Games. The relationships among sectors changed: Beijing changed from a net exporter to an importer, whereas Hebei changed from a net importer of energy from Beijing to an exporter to Beijing, and Tianjin served as an importer in both years.  相似文献   

4.
    
World food production has increased substantially in the past century, thanks mostly to the increase in the use of oil as input in the production processes. This growing use of fossil fuels has negative effects, both on the environment and the production costs. Fishing is a fuel consuming food production activity, and its energy efficiency performance has worsened over time. World‐wide fisheries are also suffering from overexploitation, which contributes to the poor efficiency performance, adding more pressure and criticism on this economic activity. In this paper we analyzed the energy efficiency performance of more than 20,000 European Union (EU) fishing vessels for the period 2002–2008, using the edible energy return on investment (EROI) indicator. The vessels analyzed, grouped in 49 different fleets, represented 25% of the vessels and 33% of the landings of the EU fishing sector. These EU fishing fleets’ average EROI for 2008 was 0.11, which translates to an energy content of the fuel burned that is 9 times greater than the edible energy content of the catch. Hence, the significance of this study arises from the use of time‐series data on a relevant part of the EU fleet that showed stable or even slight improvements on the EROI over time. Moreover, results showed that the energy efficiency of the different fleets varied significantly (from 0.02 to 1.12), mainly depending on the fishing gear and the vessel length. The performance of the most efficient fleets, such as large pelagic trawlers and seiners, was comparable to many agricultural production activities. The plausible drivers behind these trends are further considered.  相似文献   

5.
    
China has more than 1,500 industrial parks, which, collectively, play a crucial role in facilitating industrialization and urbanization. A key characteristic of these parks is that most rely on shareable energy infrastructure, an efficient configuration that can also deliver substantial and sustainable reductions in greenhouse gas (GHG) emissions. This study offers strategies for mitigating GHG emissions from Chinese industrial parks. We focus on extensive data collection for the 106 industrial parks listed in the national demonstration eco‐industrial park (EIP) program. In doing so, we carefully examine the evolution of 608 serviceable energy infrastructure units by vintage year, fuel type, energy output, and technologies of combined heat and power units. We assess direct GHG emissions from both energy infrastructure and the parks, and then identify the features and driving forces of energy infrastructure development in the EIPs. We also offer recommendations for ways to mitigate the GHG emissions from these industrial parks. The energy infrastructure stocks in Chinese EIPs are characterized by heavy coal dependence (87% of capacity) and high ratios of direct GHG emissions versus the total direct emissions of the park (median value: 75.2%). These findings establish a baseline from which both technology and policy decisions can then be made in an informed way.  相似文献   

6.
    
Global production chains carry environmental and socioeconomic impacts embodied in each traded good and service. Even though labor and energy productivities tend to be higher for domestic production in high‐income countries than those in emerging economies, this difference is significantly reduced for consumption, when including imported products to satisfy national demand. The analysis of socioeconomic and environmental aspects embodied in consumption can shed a light on the real level of productivity of an economy, as well as the effects of rising imports and offshoring. This research introduces a consumption‐based metric for productivity, in which we evaluate the loss of productivity of developed nations resulting from imports from less‐developed economies and offshoring of labor‐intensive production. We measure the labor, energy, and greenhouse gas emissions footprints in the European Union's trade with the rest of the world through a multiregional input‐output model. We confirm that the labor footprint of European imports is significantly higher than the one of exports, mainly from low‐skilled, labor‐intensive primary sectors. A high share of labor embodied in exports is commonly associated with low energy productivities in domestic industries. Hence, this reconfirms that the offshoring of production to cheaper and low‐skilled, labor‐abundant countries offsets, or even reverts, energy efficiency gains and climate‐change mitigation actions in developed countries.  相似文献   

7.
    
In the fifty years since Abel Wolman first published an estimate of U.S. urban metabolism, the field of urban metabolism has begun to thrive, with cities outside the United States being much of the focus. As cities attempt to meet local and international sustainability goals, it is time to revisit the metabolism of cities within the United States. Using existing empirical databases for material flows (the Freight Analysis Framework) and a published database on urban water flux, we provide a revised estimate of urban metabolism for the typical U.S. city. We estimate median values of metabolism for a city of one million people, considering water resources, food, fuel, and construction materials. Food consumption and waste production increased substantially to 3,800 metric tons per day and 4,900 metric tons per day, respectively. To facilitate a second generation of urban metabolism, we extend traditional analyses to include the embedded energy required to facilitate material consumption with important implications in determining sustainable urban metabolism. We estimate that a city of one million people requires nearly 4,000 gigajoules of primary energy per day to facilitate its metabolism. Our results show high heterogeneity of urban metabolism across the United States. As a result of the study, we conclude that there is a distinct need to promote policies at the regional or city scale that collect data for urban metabolism studies. Urban metabolism is an important educational and decision‐making tool that, with an increase in data availability, can provide important information for cities and their sustainability goals.  相似文献   

8.
    
The industrial park of Herdersbrug (Brugge, Flanders, Belgium) comprises 92 small and medium‐sized enterprises, a waste‐to‐energy incinerator, and a power plant (not included in the study) on its site. To study the carbon dioxide (CO2) neutrality of the park, we made a park‐wide inventory for 2007 of the CO2 emissions due to energy consumption (electricity and fossil fuel) and waste incineration, as well as an inventory of the existing renewable electricity and heat generation. The definition of CO2 neutrality in Flanders only considers CO2 released as a consequence of consumption or generation of electricity, not the CO2 emitted when fossil fuel is consumed for heat generation. To further decrease or avoid CO2 emissions, we project and evaluate measures to increase renewable energy generation. The 21 kilotons (kt) of CO2 emitted due to electricity consumption are more than compensated by the 25 kt of CO2 avoided by generation of renewable electricity. Herdersbrug Industrial Park is thus CO2 neutral, according to the definition of the Flemish government. Only a small fraction (6.6%) of the CO2 emitted as a consequence of fossil fuel consumption (heat generation) and waste incineration is compensated by existing and projected measures for renewable heat generation. Of the total CO2 emission (149 kt) due to energy consumption (electricity + heat generation) and waste incineration on the Herdersbrug Industrial Park in 2007, 70.5% is compensated by existing and projected renewable energy generated in the park. Forty‐seven percent of the yearly avoided CO2 corresponds to renewable energy generated from waste incineration and biomass fermentation.  相似文献   

9.
    
A common feature distinguishing between parametric/statistical models and engineering economics models is that engineering models explicitly represent best practice technologies, whereas parametric/statistical models are typically based on average practice. Measures of energy intensity based on average practice are of little use in corporate management of energy use or for public policy goal setting. In the context of companyor plant‐level indicators, it is more useful to have a measure of energy intensity that is capable of indicating where a company or plant lies within a distribution of performance. In other words, is the performance close to (or far from) the industry best practice? This article presents a parametric/statistical approach that can be used to measure best practice, thereby providing a measure of the difference, or “efficiency gap,” at a plant, company, or overall industry level. The approach requires plant‐level data and applies a stochastic frontier regression analysis used by the ENERGY STARTM industrial energy performance indicator (EPI) to energy intensity. Stochastic frontier regression analysis separates energy intensity into three components: systematic effects, inefficiency, and statistical (random) error. The article outlines the method and gives examples of EPI analysis conducted for two industries, breweries and motor vehicle assembly. In the EPI developed with the stochastic frontier regression for the auto industry, the industry median “efficiency gap” was around 27%.  相似文献   

10.
    
Since 1989, efforts to understand the nature of interfirm resource sharing in the form of industrial symbiosis and to replicate in a deliberate way what was largely self‐organizing in Kalundborg, Denmark have followed many paths, some with much success and some with very little. This article provides a historical view of the motivations and means for pursuing industrial symbiosis—defined to include physical exchanges of materials, energy, water, and by‐products among diversified clusters of firms. It finds that “uncovering” existing symbioses has led to more sustainable industrial development than attempts to design and build eco‐industrial parks incorporating physical exchanges. By examining 15 proposed projects brought to national and international attention by the U.S. President's Council on Sustainable Development beginning in the early 1990s, and contrasting these with another 12 projects observed to share more elements of self‐organization, recommendations are offered to stimulate the identification and uncovering of already existing “kernels” of symbiosis. In addition, policies and practices are suggested to identify early‐stage precursors of potentially larger symbioses that can be nurtured and developed further. The article concludes that environmentally and economically desirable symbiotic exchanges are all around us and now we must shift our gaze to find and foster them.  相似文献   

11.
    
Using data from the water service area of the East Bay Municipal Utility District in Northern California, we develop and discuss a method for assessing, at a high resolution, the energy intensity of water treated and delivered to customers of a major metropolitan water district. This method extends previous efforts by integrating hourly data from supervisory control and data acquisition systems with calculations based on the actual structure of the engineered infrastructure to produce a detailed understanding of energy use in space and time within the territory of a large‐scale urban water provider. We found significant variations in the energy intensity of delivered potable water resulting from seasonal and topographic effects. This method enhances our understanding of the energy inputs for potable water systems and can be applied to the entire delivery and postuse water life cycle. A nuanced understanding of water's energy intensity in an urban setting enables more intelligent, targeted efforts to jointly conserve water and energy resources that take seasonal, distance, and elevation effects into account.  相似文献   

12.
    
The deployment of renewable energy generation technologies, driven primarily by concerns over catastrophic climate change, is expected to increase rapidly in the United States. Rapid increases in the deployment of wind and solar energy will translate to increases in critical material requirements, causing concern that demand could outstrip supply, leading to mineral price volatility and potentially slowing the energy transition. This study presents a detailed demand-side model for wind and solar in the United States using dynamic material flow analysis to calculate the requirements for 15 elements: Cr, Zn, Ga, Se, Mo, Ag, Cd, In, Sn, Te, Pr, Nd, Tb, Dy, and Pb. Results show that transitioning to a completely decarbonized US energy system by 2050 could require a five-to-sevenfold increase in critical material flow-into-use compared with business as usual (BAU), with some materials requiring much larger increases. Rare earth elements (REEs) could require 60–300 times greater material flows into the US power sector in 2050 than in 2021, representing 13%–49% of the total global REE supply. Te requirements for reaching net zero by 2050 could exceed current supply, posing challenges for widespread deployment of cadmium-telluride solar. We also investigate several strategies for reducing material requirements, including closed-loop recycling, material intensity reduction, and changing market share of subtechnologies (e.g., using crystalline silicon solar panels instead of cadmium telluride). Although these strategies can significantly reduce critical material requirements by up to 40% on average, aggressive decarbonization will still require a substantial amount of critical material.  相似文献   

13.
    
Eco‐industrial networks (EINs, of which eco‐industrial parks are a subset) have gained support as a solution that simultaneously reduces environmental burdens and promotes economic interests. EINs operate under a mutualistic framework, where waste materials and energy are exchanged between industries to their mutual benefit, creating a diverse web of flows. Recent studies have focused on analogies between food webs (FWs) and EINs, measuring a network's success at ecological imitation as representative of its sustainability. Studies have focused heavily on the number of links and nodes in a network, but have neglected the economic reality that each investment comes at the opportunity cost of all alternatives. This analysis focuses on the nestedness metric as used by ecologists to address this pivotal facet to the FW‐EIN analogy. Nestedness describes an ecological strategy for the position of links between nodes in a network in a way that maximizes network cycling for a given number of connections. This metric presents many advantages for EIN design and analysis, including maturity independence, size normalization, and a strong statistical record in highly mutualistic ecological systems. Application of nestedness to EINs indicates a lower presence of nested structures and more randomness than what is typically seen in FWs. The industrial networks also display a correlation between high nestedness and internal cycles, suggesting that the reuse of materials and energy in EINs can be improved upon by increasing the nestedness of structures.  相似文献   

14.
    
Cyclical industrial networks are becoming highly desirable for their efficient use of resources and capital. Progress toward this ideal can be enhanced by mimicking the structure of naturally sustainable ecological food webs (FWs). The structures of cyclic industrial networks, sometimes known as eco‐industrial parks (EIPs), are compared to FWs using a variety of important structural ecological parameters. This comparison uses a comprehensive data set of 144 FWs that provides a more ecologically correct understanding of how FWs are organized than previous efforts. In conjunction, an expanded data set of 48 EIPs gives new insights into similarities and differences between the two network types. The new information shows that, at best, current EIPs are most similar to those FWs that lack the components that create a biologically desirable cyclical structure. We propose that FWs collected from 1993 onward should be used in comparisons with EIPs, given that these networks are much more likely to include important network functions that directly affect the structure. We also propose that the metrics used in an ecological analysis of EIPs be calculated from an FW matrix, as opposed to a community matrix, which, to this point, has been widely used. These new insights into the design of ecologically inspired industrial networks clarify the path toward superior material and energy cycling for environmental and financial success.  相似文献   

15.
This article focuses on the effects of policy instruments for developing viable eco‐industrial parks (EIPs) in China. We analyzed the root of China's national EIP program and inventoried the general instruments available to local authorities to shape and promote eco‐industrial development. Empirical research conducted in Tianjin Economic‐technological Development Area and Dalian Development Area led to the activities and actions conducted by local authorities. A quantitative method, technique for order of preference by similarity to ideal solution, was adopted to reveal the effects of policy instruments for comparative analysis. We conclude that the planned EIP model is useful in the early stage of EIP development, and, subsequently, it should be combined with a facilitated model to achieve long‐term goals for eco‐transformation. To this end, the policy package of economic, regulatory, and voluntary instruments should be integrated and tailored in alignment with the local situation.  相似文献   

16.
    
In this article, we present methodology and results of a vulnerability assessment of the energy system of the metropolitan region Bremen‐Oldenburg in Northwest Germany. This work is part of the regional climate adaptation project “nordwest2050” aiming at innovative solutions toward a climate‐proof and resilient region. Methodologically, we extended the established vulnerability assessment based on climate change impacts by a structural analysis, highlighting general weaknesses of the metropolitan energy system. Our findings indicate that the structural vulnerabilities of the energy system around Bremen‐Oldenburg pose a greater threat to maintaining the system's services than climate change itself. Climate‐change–based vulnerabilities, however, aggravate many of the structural vulnerabilities and therefore demand attention in their own right. The structural vulnerabilities mainly originate from political and regulatory uncertainties, turbulent market conditions, conflicts along the supply chains, and the current dynamics in the energy sector induced by increased climate mitigation efforts. One of our main conclusions is thus that the metropolitan energy system's capabilities to handle turbulence, perturbations, and surprises must be improved. This will also help in reducing the climate‐change vulnerabilities, because such a system is better equipped when facing currently hard‐to‐predict changes in climate parameters. The results of the assessment described here will be used as the starting point to find options for innovations toward a climate‐proof and resilient energy system for the region in the course of the remaining project.  相似文献   

17.
    
The market for photovoltaic (PV) electricity generation has boomed over the last decade, and its expansion is expected to continue with the development of new technologies. Taking into consideration the usage of valuable resources and the generation of emissions in the life cycle of photovoltaic technologies dictates proactive planning for a sound PV recycling infrastructure to ensure its sustainability. PV is expected to be a “green” technology, and properly planning for recycling will offer the opportunity to make it a “double‐green” technology—that is, enhancing life cycle environmental quality. In addition, economic feasibility and a sufficient level of value‐added opportunity must be ensured, to stimulate a recycling industry. In this article, we survey mathematical models of the infrastructure of recycling processes of other products and identify the challenges for setting up an efficient one for PV. Then we present an operational model for an actual recycling process of a thin‐film PV technology. We found that for the case examined with our model, some of the scenarios indicate profitable recycling, whereas in other scenarios it is unprofitable. Scenario SC4, which represents the most favorable scenario by considering the lower bounds of all costs and the upper bound of all revenues, produces a monthly profit of $107,000, whereas the least favorable scenario incurs a monthly loss of $151,000. Our intent is to extend the model as a foundation for developing a framework for building a generalized model for current‐PV and future‐PV technologies.  相似文献   

18.
Eco‐industrial initiatives, which close industrial loops by turning wastes at one point in a value chain into inputs at another point, are attracting growing interest as a solution to the problem of sustainability of industrial systems. Although Germany and Japan have made important advances in building recycling incentives into their industrial systems and sought competitive advantage from doing so, China is arguably taking the issue even further (in principle) through its pursuit of a circular economy, now enshrined in law as an official national development goal. In this article, we review a number of the eco‐industrial initiatives taken in China and compare them using a common graphical representation with comparable initiatives taken in the West and elsewhere in East Asia. Our aim is to demonstrate some common themes across the case studies, such as the transformation from the former linear economy to a circular economy and the evolutionary processes in which dynamic linkages are gradually established over time. We discuss the drivers of these eco‐industrial initiatives as well as the inhibitors, setting the initiatives in an evolutionary framework and introducing a notion of Pareto eco‐efficiency to evaluate them. We make the argument that China might be capturing latecomer advantages through its systematic promotion of eco‐industrial initiatives within a circular economy framework.  相似文献   

19.
    
Studies investigated the patient‐care (in‐hospital) and outside‐the‐hospital energy consumptions for delivering the hemodialysis (HD) service. A life cycle inventory methodology was used for this patient‐based analysis for two hospitals located in Wichita, Kansas. It was found that, for both hospitals, the actual HD machines consumed approximately 3.5 kilowatt‐hours (kWh) of electrical energy per HD, only 8% to 16% of the total energy used for delivering the HD service (in hospital). This increases to 9.6 to 28.9 kWh of hospital billable energy for the whole system of HD machine, auxiliaries, and dialysis water treatment. Converting these hospital direct electrical energy values to natural resource energy (nre) then adding the cradle‐to‐gate natural resource energy for the manufacturing and supply chain of all the HD consumables, the total is 78 to 149 kWh nre/HD. The nre measures all the direct fuel burned to generate energy and is thus directly related to emissions to the air, water, and land and is a direct secondary impact on public health from HD. The ratio of outside‐the‐hospital energy to direct hospital HD electrical energy consumption is 4:1 to 7:1, so a broader base exists for improvement than just the hospital.  相似文献   

20.
    
ABSTRACT

Wind energy is a reliable source for fulfilling energy demand. However, the wind power usage remains limited due to the investmental risks. Governments’ support on renewable energy compensates these risks partially. Traditional investment evaluation techniques that do not consider the compensations and risks associated with the wind energy investments are one of the main reasons for the limited usage of wind power. In this study a real option and Monte Carlo simulation–based methodology, which considers both risks and compensations associated with these investments, is proposed to evaluate wind energy investments. The model is applied to a wind turbine investment in Turkey in order to show the applicability of the proposed model. The results indicate that the option value created through wind energy investments due to the governmental compensations is very high; therefore the traditional investment techniques are not appropriate for evaluating wind energy investments.  相似文献   

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