Enabling Future Sustainability Transitions

Life cycle water use of coal- and natural-gas-fired power plants with and without carbon capture and storage

Electrification and clean hydrogen are promising low-carbon options for decarbonizing industrial process heat, which is an essential target for reducing sector-wide emissions. However, industrial processes with heat demand vary significantly across industries in terms of temperature requirements, capacities, and equipment, making it challenging to determine applications for low-carbon technologies that are technically and economically feasible. In this analysis, we develop a framework for evaluating life cycle emissions, water use, and cost impacts of electric and clean hydrogen process heat technologies and apply it in several case studies for plastics and petrochemical manufacturing industries in the United States. Our results show that industrial heat pumps could reduce emissions by 12-17% in a typical poly(vinyl chloride) (PVC) facility in certain locations currently, compared to conventional natural gas combustion, and that other electric technologies in PVC and ethylene production could reduce emissions by nearly 90% with a sufficiently decarbonized electric grid. Life cycle water use increases significantly in all low-carbon technology cases. The levelized cost of heat of viable low-carbon technologies ranges from 15 to 100% higher than conventional heating systems, primarily due to energy costs. We discuss results in the context of relevant policies that could be useful to manufacturing facilities and policymakers for aiding the transition to low-carbon process heat technologies.

This article provides consolidated estimates of water withdrawal and water consumption for the full life cycle of selected electricity generating technologies, which includes component manufacturing, fuel acquisition, processing, and transport, and power plant operation and decommissioning. Estimates were gathered through a broad search of publicly available sources, screened for quality and relevance, and harmonized for methodological differences. Published estimates vary substantially, due in part to differences in production pathways, in defined boundaries, and in performance parameters. Despite limitations to available data, we find that: water used for cooling of thermoelectric power plants dominates the life cycle water use in most cases; the coal, natural gas, and nuclear fuel cycles require substantial water per megawatt-hour in most cases; and, a substantial proportion of life cycle water use per megawatt-hour is required for the manufacturing and construction of concentrating solar, geothermal, photovoltaic, and wind power facilities. On the basis of the best available evidence for the evaluated technologies, total life cycle water use appears lowest for electricity generated by photovoltaics and wind, and highest for thermoelectric generation technologies. This report provides the foundation for conducting water use impact assessments of the power sector while also identifying gaps in data that could guide future research.

Life cycle water use and wastewater discharge of steel production based on material-energy-water flows: A case study in China

Hydrogen is a potential solution for hard-to-abate industries while undergoing transitioning to a net-zero economy. Low-carbon hydrogen can be produced from renewable and fossil resources by electrolysis and reforming or gasification with carbon capture by using clean electricity, respectively. This study comparatively evaluates the life cycle water use of various hydrogen production pathways, which varies with feedstock type, production technology, electricity and water supply sources, cooling technology, and production location. Among the stages across the life cycle, hydrogen plant operation and electricity supply dominate the life cycle water use for hydrogen production. The competitiveness of water footprints for electrolysis compared to reforming or gasification with carbon capture highly depends on the source of electricity supplied for hydrogen production, even in a net-zero economy. The lowest life cycle water consumption can be achieved by integrating wind-powered electrolysis with dry cooling at a hydrogen production plant. Dry cooling and alternative water sources can be employed to reduce the use of freshwater for hydrogen production. Hydrogen, water, and electricity are interlinked and should be coordinated locally to ensure sustainability in the three dimensions.

Life cycle water use of a biomass-based pyrolysis polygeneration system in China

Life Cycle Water Use for Electricity Generation: Implications of the Distribution of Collected EstimatesThis article provides consolidated estimates of water withdrawal and water consumption for the full life cycle of selected electricity generating technologies, which includes component manufacturing, fuel acquisition, processing, and transport, and power plant operation and decommissioning. Estimates were gathered through a broad search of publicly available sources, screened for quality and...Author(s)James MeldrumJordan MacknickGarvin HeathSyndi Nettles-AndersonSourceProceedings of the Water Environment FederationDocument typeConference PaperPublisherWater Environment FederationPrint publication date May, 2013ISSN1938-6478DOI10.2175/193864713813503305Volume / Issue2013 / 3Content sourceEnergy ConferenceCopyright2013Word count190

Life cycle water use of low-carbon transport fuels

Water use of a biomass direct-combustion power generation system in China: A combination of life cycle assessment and water footprint analysis

Circular Urban Metabolism Framework

The article aims to provide an initial insight into if and how urban metabolism perspectives and approaches may strengthen accountability in urban environmental strategic planning. It argues that many of the challenges in governing urban environmental flows successfully result from accountability gaps in strategic planning. The aim of the research is to test the assumption that urban metabolism perspectives and approaches strengthen accountability in urban environmental strategic planning. Applying a four-pillar accountability analysis to the strategic climate and resource plans of New York and Zurich, two cities which put environmental sustainability high on their political agenda, the study traces the role of urban metabolism perspectives and approaches and discusses the benefits these may have for accountable strategic planning with a focus on carbon and material flows. The interim results show on the one hand that implicit urban metabolism approaches are vital for both cities’ strategic planning and that they contribute to strengthened accountability in all four pillars of the analysis: responsibility, transparency, assessment and participation. On the other hand, the analysis highlights further potential benefits of urban metabolism perspectives and approaches in urban strategic climate and resource planning.

Tradeoffs in life cycle water use and greenhouse gas emissions of hydrogen production pathways

The water scarcity is becoming a growing concern. Regarded as a potential CO emission mitigation technology for coal-fired power plants, oxy-fuel combustion, a typical CCS technology, theoretically consumes a large amount of water, which increases the severity of the water scarcity. Therefore, revealing the water use of oxy-fuel coal-fired power plants is of great importance for the deployment of CCS technologies under water resource constraint in the future. In this respect, the aim of this study is to evaluate the life cycle water use of oxy-fuel CO capture, transport and storage via a 600 MW coal fired oxy-fuel power plant in China. By using a tiered hybrid life cycle assessment, both direct and indirect water use are calculated. Results show 22.9L H O/kg of CO and the oxy-fuel power plant stage dominates the total water use, while the water intensity for power generation is calculated as 3233.3 L H O/MWh, which is higher than the conventional power plants. Sensitivity analysis is performed in this research and indicates that the variation of tap water use affects the water intensity immensely. Furthermore, the use of the membrane method for air separation decreases the overall water use 14.21% respectively. China is continually increasing its efforts to reduce carbon emissions due to both domestic and international pressure. Hence the development and implement of the CCS technology is of great urgency. At the end of this study possible solutions such as using wasted or discarded wind power for the separation of oxygen to minimize water use in oxy-fuel power plant stage are put forward.

This work provides consolidated estimates of water withdrawal and water consumption requirements for the full life cycle of photovoltaic (PV) systems, including component manufacturing, power plant construction, system operation, and decommissioning. Life cycle data were also collected for other types of electricity generating technologies for comparison purposes. Published estimates were gathered through a broad search of publicly available sources, screened for quality and relevance, and harmonized for methodological differences, when possible. Compared with other electricity generating technologies, the total life cycle water use for PV systems are lower than all other technologies except for wind technologies.

IntroductionNowadays, urban metabolism (UM) is believed to provide new insights for more sustainable resource management in cities and their hinterlands. UM studies, however, focalize chiefly on quantitative resource input and output (e.g. energy, materials) and tend to neglect the element of space and the qualitative characteristics of the urban landscape. This paper explores the use of UM as a basis for planning and design, focusing on the design process and on landscape configuration, in an attempt to bridge the gap between such an approach and the perceptions of urban inhabitants.Case descriptionTwo case studies on the metropolitan scale based on UM quantification which aim to develop projects that can improve urban sustainability are analyzed: the International Architecture Biennale of Rotterdam and the Amsterdam Urban Pulse project. Subsequently, De Ceuvel is explored, an experimental neighborhood in Amsterdam that deployed the UM approach to develop a participatory design and implementation process.Discussion and EvaluationThe method consists in a case study analysis centered on field work, document analysis, and semi-structured interviews with the designers involved, while the inhabitants’ points of view are also polled on the neighborhood scale.ConclusionsThe key results highlight how the UM approach can be integrated with spatial design in two different ways, according to the scales implicated. On the metropolitan scale, UM provides a means of identifying key locations and proposing interventions that can improve a city’s global metabolism. On the scale of the neighborhood, however, the UM approach aims to close the energy and material cycles on the design plot, though without necessarily connecting the neighborhood to the city network.