| 41. |
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| 42. |
- Jerome, Adeline, 1994, et al.
(författare)
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Environmental sustainability of high voltage motors: do better efficiency and repair lead to improved environmental impact?
- 2022
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Konferensbidrag (övrigt vetenskapligt/konstnärligt)abstract
- Various circular economy (CE) strategies, for instance lifetime extension by repair or reuse, have been suggested to improve products’ environmental performance. The literature emphasises the need to better understand the consequences of those CE strategies with assessment tools such as life cycle assessment (LCA). From previous assessments, Böckin et al. (2020) identifies energy use reduction and use extension by maintenance, repair or remanufacturing as relevant CE strategies for durable and active products. However, this conclusion is based on assessments of small- and medium-size electronic products, leaving out more durable and more energy consuming bigger products. In this study, the implementation of two CE strategies, energy use reduction and use extension by repair, is explored for high voltage (HV) motors delivering 135GWh per year over at least 20 years. Electric motors are prominent active products, representing 50% of the electricity consumption in Europe. Even in small numbers, HV motors represent a significant share of this consumption due to their more intensive use and high output power. Two main HV motor technologies exist: induction motors (IM) and synchronous motors (SM), which are more energy efficient. Both are often used until failure, which frequently occurs in stator windings but could be repaired by rewinding at the expense of a slight decrease in efficiency. This study aims to compare the life-cycle environmental impact of the two motor technologies and to explore their lifetime extension by repair in comparison to their replacement. For each motor technology, a cradle-to-grave LCA is performed for global warming and mineral and metal resource depletion impact categories. The IM has an efficiency of 97.3%, the SM an efficiency of 98.3% and both are run 20 years. Results show that the impact of electricity consumption during use is dominant. Besides, the SM has a lower environmental impact than the IM. In term of resource depletion, SM manufacturing is more impactful but lower energy losses during use compensate for the difference. Repair is modelled with the production of a new stator winding and a decrease in efficiency of 0.7%. Three scenarios are compared. The IM is initially used for 20 years, and an additional 10 years of use is provided by either 1) replacing with an IM with the same efficiency, 2) replacing with the SM, or 3) repair by rewinding. LCA results show that the additional energy losses after repair in scenario 3 offset the gain from avoiding the production of a new motor compared to scenarios 1 and 2. This study shows that the long lifetime and high energy requirements of HV motors lead the energy efficiency to be an essential factor for the life-cycle environmental performance. Choosing and maintaining high energy efficiency is key in this situation, especially for lifetime extension strategies to be beneficial for the product environmental performance. Reference: Böckin et al. (2020), How product characteristics can guide measures for resource efficiency. Resources, Conservation and Recycling 154, 104582.
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| 43. |
- Jerome, Adeline, 1994, et al.
(författare)
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Is repair of energy using products environmentally beneficial? The case of high voltage electric motors
- 2023
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Ingår i: Resources, Conservation and Recycling. - 0921-3449 .- 1879-0658. ; 196
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Tidskriftsartikel (refereegranskat)abstract
- Repair is advocated as a circular strategy to improve the environmental performance of products. Whether this holds for very long-lived and energy intensive products has not been addressed. This study compares environmental impacts of two high voltage motors of different energy efficiency and assesses their use extension by repair with life cycle assessment (LCA). Due to high energy use, long lifetime and intensive use, the use phase dominates all environmental impacts, even resource depletion. Therefore, a higher energy efficiency is more beneficial than extending the use by repair, and if the energy efficiency is slightly reduced, the repair is not beneficial. Therefore, product requirements and users and manufacturers of such products should ensure designs with high energy efficiency rather than making the product repairable. Finally, the results highlight the importance of including resource use from electricity production and transmission in LCA of the use extension of energy using products.
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| 44. |
- Jerome, Adeline, 1994, et al.
(författare)
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Repair for high-voltage electric motors energy efficiency vs resource use?
- 2022
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Konferensbidrag (övrigt vetenskapligt/konstnärligt)abstract
- Electric motors in the industry represent 69% of the industrial electricity consumption in Europe. Even if few in number, high voltage (HV) motors represent a significant share of this consumption due to their more intensive use and high output power. Two main HV motor technologies exist: induction motors (IM) and synchronous motors (SM), of which the latter are more energy efficient. Improving energy efficiency as well as use extension by maintenance, repair or remanufacturing have been identified as relevant circular economy strategies for improving the environmental performance of such active and durable products. However, the assessments performed focus on small- and medium-size electronic products, leaving out bigger products that are more durable and more energy consuming such as HV motors. Those motors are often used until failure, which frequently occurs in stator windings, and which could be repaired by rewinding at the expense of a slight decrease in efficiency. However, other use extension strategies such as reuse and remanufacturing are hindered by the customization of HV motors to their specific use. Finding an appropriate set-up for a second use is difficult for such motors and it is therefore performed seldom. The aim of this study is to compare the life-cycle environmental impact of lifetime extension by repair for the two motor technologies in comparison to their replacement.
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| 45. |
- Jerome, Adeline, 1994, et al.
(författare)
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When is repair environmentally beneficial? The case of high-voltage electric motors
- 2023
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Konferensbidrag (övrigt vetenskapligt/konstnärligt)abstract
- Use extension by repair is a circular economy (CE) strategy that has been advocated to improve products’ environmental performance and resource efficiency. Previous studies have shown that this does not necessarily hold for energy-using products, for instance, when a more energy-efficient product is available for replacement. The requirements for use extension to be beneficial have been found to vary with the product and its use conditions. However, resource depletion is seldom discussed, and the case of very long-lived and energy-intensive products has not been addressed yet. An example of such an energy-intensive product is high-voltage (HV) electric motors, typically used for more than 20 years and in operation for 50 weeks a year full time. Electric motors represent 50% of the electricity consumption in Europe and despite being few, HV motors represent a significant share of this consumption. The two HV motor designs, induction motors (IM) and synchronous motors (SM), are often used until failure, commonly occurring in stator windings which could be repaired but with the risk of affecting energy efficiency. This work aims to provide recommendations on important aspects for use extension to be environmentally beneficial for long-lived and energy-intensive products. Cradle-to-grave LCAs are performed for global warming and mineral resource depletion to compare (1) the two motor designs and (2) each motor with and without use extension through repair. The motors are chosen to deliver the same output of 16 MW and the functional unit is set to one year of operation. The IM has an energy efficiency of 97.3%, the SM has an efficiency of 98.3% and both are run for 20 years. The additional use time and the efficiency reduction after the repair are left as varying parameters between 1 and 20 years and between 0 and 1% respectively. Results show that, due to high energy use and long lifetime, the impact of electricity use during motor use is dominant for both global warming and resource depletion. This dominance remains with different electricity mixes, including in a scenario with hydroelectricity only. For resource depletion, it is due to copper in transmission lines and resources for electricity production (e.g., uranium from nuclear energy production). The dominance of the use phase results in energy efficiency being key to the environmental performance of HV motors. The more efficient design, the SM, results in lower impacts than the IM in both impact categories. In terms of resource depletion, SM manufacturing is more impactful but lower energy losses during use compensate for the difference. Besides, additional energy losses from a small energy efficiency reduction offset the gain from the repair for both global warming and resource depletion. The gain from the use extension by repair is small compared to the benefit of choosing the more efficient design. Choosing and maintaining high energy efficiency is key for long-lived and energy-intensive products’ environmental performance due to their high energy requirements and long lifetime. Thus, efforts should be channelled on ensuring high energy efficiency by design and after repair. This is relevant for both policy-making and manufacturers or users when prioritising strategies for improving products’ environmental performance. Finally, as conclusions are similar for global warming and resource depletion, this work demonstrates the importance of including resource use from electricity production and transmission when exploring the use extension of energy-using products.
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| 46. |
- Johansson, Björn, 1975, et al.
(författare)
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Evaluation and Calculation of Dynamics in Environmental Impact Assessment
- 2013
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Ingår i: IFIP Advances in Information and Communication Technology. - Berlin, Heidelberg : Springer Berlin Heidelberg. - 1868-4238 .- 1868-422X. - 9783642403514 ; 397:1, s. 135-141
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Konferensbidrag (refereegranskat)abstract
- In ten years customers will select products not only based on price and quality but also with strong regard to the product value environmental footprint, including for example the energy consumed. Customers expect transparency in the product realization process, where most products are labeled with their environmental footprint. Vigorous companies see this new product value as an opportunity to be more competitive. In order to effectively label the envi-ronmental impact of a product, it is pertinent for companies to request the envi-ronmental footprint of each component from their suppliers. Hence, companies along the product lifecycle require a tool, not only to facilitate the computing of the environmental footprint, but also help reduce/balance the environmental impact during the lifecycle of the product. This paper proposes to develop a procedure that companies will use to evaluate, improve and externally advertise their product’s environmental footprint to customers.
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| 47. |
- Johansson, Björn, 1975, et al.
(författare)
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Power Level Sampling of Metal Cutting Machines for Data Representation in Discrete Event Simulation
- 2015
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Ingår i: International Journal of Production Research. - : Informa UK Limited. - 0020-7543 .- 1366-588X. ; 53:23, s. 7060-7070
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Tidskriftsartikel (refereegranskat)abstract
- An extension to the application area for discrete event simulation (DES) has been ongoing since the last decade and focused only on economic aspects to include ecologic sustainability. With this new focus, additional input parameters, such as electrical power consumption of machines, are needed. This paper aim at investigating how NC machine power consumption should be represented in simulation models of factories. The study includes data-sets from three different factories. One factory producing truck engine blocks, one producing brake disc parts for cars and one producing forklift components. The total number of data points analysed are more than 2,45,000, where of over 1,11,000 on busy state for 11 NC machines. The low variability between busy cycles indicates that statistical representations are not adding significant variability. Furthermore, results show that non-value-added activities cause a substantial amount of the total energy consumption, which can be reduced by optimising the production flow using dynamic simulations such as DES.
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| 48. |
- Kanchiralla, Fayas Malik, 1989, et al.
(författare)
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Life-Cycle Assessment and Costing of Fuels and Propulsion Systems in Future Fossil-Free Shipping
- 2022
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Ingår i: Environmental Science and Technology. - : American Chemical Society (ACS). - 0013-936X .- 1520-5851. ; 56:17, s. 12517-12531
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Tidskriftsartikel (refereegranskat)abstract
- Future ships need to operate with low or possibly zero greenhouse gas (GHG) emissions while ensuring low influence on other environmental impacts and that the operation is economically feasible.This study conducts a life-cycle evaluation of potential decarbonization solutions involving selected energy carriers (electrolytic hydrogen, electro-ammonia, electro-methanol, and electricity) in different propulsion system setups (engines, fuel cells, and carbon capture technologies) in terms of environmental impact and costs.The results of the study show that the assessed decarbonization options are promising measures to reduce maritime GHG emissions with low-carbon-intensive electricity.The same order of GHG reduction is shown to be possible independent of the propulsion system and energy carrier used onboard.However, the carbon abatement cost ranges from 300 to 550 €/tCO2eq, and there is a trade-off with environmental impacts such as human toxicity (cancer and non-cancer effects) and freshwater ecotoxicity mainly linked with the wind infrastructure used for electricity production.Electro-ammonia in fuel cells is indicated to be effective in terms of the carbon abatement cost followed by the so-called HyMethShip concept.The higher abatement cost of all options compared to current options indicates that major incentives and policy measures are required to promote the introduction of alternative fuel and propulsion systems.
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| 49. |
- Kanchiralla, Fayas Malik, 1989
(författare)
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Life cycle navigation through future energy carriers and propulsion options for the energy transition in shipping
- 2023
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Licentiatavhandling (övrigt vetenskapligt/konstnärligt)abstract
- The shipping industry's heavy reliance on fossil fuels has a detrimental effect on the global climate, human health, and the natural environment. The shipping sector now relies on the use of cheap and energy-dense heavy fuel oil and is perceived as ‘difficult-to-decarbonize’. Presently the shipping sector is adopting incremental emission reduction measures related to operational and technological energy efficiency solutions. However, to meet the global climate target, the transition from fossil-based marine fuels to renewable energy carriers is needed. Electro-fuels, which are produced from low-carbon electricity, or direct use of electricity with battery storage, are two pathways for energy transition included in this thesis. This thesis aims to assess the possible influence of the above two decarbonization paths based on energy demand, environmental performance, and economic performance across the whole life cycle of ships. The assessment is performed for hydrogen, ammonia, methanol, and battery-electric on three case study vessels using prospective life cycle assessment (pLCA) and life cycle costing (LCC). The pLCA is based on systems thinking used for the environmental assessment of emerging technologies that are in an early stage of development, and the LCC is used for the economic assessment of technologies over the life cycle based on the same systems thinking. To understand the environmental and economic tradeoffs for decision making an integrated assessment of pLCA and LCC is employed in the thesis. Considering the complexity and challenges of integration, a framework termed ‘integrated life cycle framework’ is developed for this thesis, allowing for consistent assessment to understand tradeoffs. This framework can be useful for other transport sectors. The study shows that there is a substantial potential for reducing the environmental impact of shipping through the studied pathways; however, this depends on the carbon intensity of the electricity used in fuel production. Technically, not all fuels are suitable for all vessels. Their suitability is primarily determined by the amount of fuel required for bunkering and the amount of space available onboard. Reduced climate impact comes at the expense of several other impact categories, such as human toxicity, water use, and resource use (minerals and metals). For the same type of fuel, fuel cells have greater impact reduction potential than engine options; however, engines are more cost competitive. Fuel price and utilization rate also influence cost competitiveness. The total life cycle cost of all the studied options is significantly higher than the conventional diesel option, and the critical parameter is the cost of the fuel. The cost of fuel is sensitive to the price of electricity. The carbon abatement cost estimated in this study shows that policies should be designed to imply at least a cost of 250–300 €/tCO2eq for emitting greenhouse gases to make the assessed fuel options cost competitive.
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| 50. |
- Karlsson, Ida, 1980, et al.
(författare)
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Mistra Carbon Exit Technical roadmap - Buildings and transport infrastructure
- 2020
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Rapport (övrigt vetenskapligt/konstnärligt)abstract
- This report explores different possible trajectories of technological developments in the supply chains of buildings and transportation infrastructure. By linking short-term and long-term goals with specific technology options, the Mistra Carbon Exit roadmaps describe key decision points and potential synergies, competing goals and lock-in effects. The analysis combines quantitative analytical methods, i.e. scenarios and stylized models, with participatory processes involving relevant stakeholders in the roadmap assessment process. The roadmaps outline material and energy flows along with costs associated with different technical and strategical choices and explore interlinkages and interactions across sectors. The results show how strategic choices with respect to process technologies, energy carriers and the availability of biofuels, carbon capture, transport and storage (CCS) and carbon neutral electricity may have very different implications on energy use and CO2 emissions over time.
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