Repair or replace? Guidance from indicators and life cycle assessment on circular economy strategies for energy-using products

Various circular economy (CE) strategies, such as use extension with repair or reuse, have been suggested as a means for addressing the increasing resource and environmental footprint of society. To identify effective CE strategies, companies or policy makers seek guidance from the evaluation of resource use and environmental impact of alternatives that introduce different CE strategies to product systems. CE indicators and life cycle assessment (LCA) have been used for that purpose. However, a clear description of the differences between these two assessment methods as well as of the aspects accounted for by CE indicators is still missing. Therefore, the aim of this licentiate thesis is to advance the description of CE indicators and LCA in order to provide recommendations for practitioners to select the appropriate assessment method for their specific assessment goal.To this end, LCA and CE indicators are compared by considering the type of results generated and the modelling specifications. Specific attention is given to the assessment of use extension of energy using products (EuP). This comparison builds on two studies: a review and analysis of CE indicators which identify the flows and processes that indicators account for and how indicators’ and LCA results differ, and an LCA of the repair of a long-lived and energy intensive product which identifies what aspects are important to consider in the assessment of this overlooked product category.The comparison shows that the two assessment methods provide different types of results. CE indicators inform on variations of resource use and especially on variations that are relative to other flows in the product system. LCA provides information on the environmental impacts and thus makes it possible to identify trade-offs between different types of environmental impacts. Besides, LCA allows a greater flexibility than CE indicators in capturing flows and processes but requires an extensive data collection. In comparison, CE indicators, and especially indicators focusing on one CE strategy at a time, have the advantage of being more time-efficient and of providing a detailed description of variations in resource use.For assessing the reuse or repair of EuP, CE indicators are more limited than LCA with regards to ensuring that important changes in resource use are not missed. No indicator accounts for resource use in the use phase, and thus for changes in energy efficiency by design or with repair and for resources in energy production and transmission. These have however been found to be key aspects in the environmental performance of the repair of an energy intensive EuP. Therefore, to decide on a repair or replacement, the selection of CE indicators and LCA as assessment methods depends on the type of impacts that a practitioner wants to base its decision on (e.g., environmental impact and/or resource use) and on the important modelling specifications for the product system (e.g., resources in energy production and transmission for the repair of an energy intensive EuP). Further research could focus on understanding the needs from practitioners in specific contexts to develop the practicability of these recommendations and on exploring other central modelling aspects for use extension such as the product’s lifetime

Repair for high-voltage electric motors energy efficiency vs resource use?

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

Repair for high‐voltage electric motors: energy efficiency vs resource use?

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. Please click Additional Files below to see the full abstract

Environmental sustainability of high voltage motors: do better efficiency and repair lead to improved environmental impact?

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, B\uf6ckin 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:B\uf6ckin et al. (2020), How product characteristics can guide measures for resource efficiency. Resources, Conservation and Recycling 154, 104582

Is repair of energy using products environmentally beneficial? The case of high voltage electric motors

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

Mapping and testing circular economy product-level indicators: A critical review

Numerous indicators have been suggested as tools for assessing progress towards the circular economy (CE). However, it is unclear what specifically is captured by CE indicators and few studies have tested them on real cases. This review addresses this gap by describing and comparing the resource-related effects captured by existing resource-based product-level indicators and suggesting recommendations for their use and further development. First, the flows and processes quantified by product-level indicators are mapped on a novel flowchart model, which can also be used to select and develop indicators. Second, the indicators are tested on seven real cases. Third, indicator and life cycle assessment (LCA) results are compared. A significant divergence of indicators’ scope is found, where most capture a limited part of the product system. Moreover, important aspects of the CE are not captured: no indicator accounts for resource use in the use phase and there is limited attention to lifetime extension strategies. Additional limitations are the difficulties to assess multiple use-cycles and that most indicators cannot capture absolute mass variations, thus neglecting mass reduction strategies. The testing reveals that using a set of single-focus indicators may be necessary to outline trade-offs. Multi-focus indicators are sometimes harder to analyse but provide a more comprehensive assessment. The testing also illustrates that indicator and LCA results are not necessarily aligned. The latter provides information on environmental impacts and can point to trade-offs between impact categories such as climate change, resource use and land use, indicating that CE indicators cannot easily replace LCA

Exploring the Relationship between Environmental and Economic Payback Times, and Heritage Values in an Energy Renovation of a Multi-Residential Pre-War Building

Cultural value and heritage have been identified as necessary for a sustainable living environment, alongside environmental concern and energy efficiency. In this study, multiple methods, i.e., life cycle assessment, payback, and questionnaires and interviews with tenants, and empirical data from a recent energy renovation of a multi-residential pre-war building with wooden construction were used to analyse the impact of the renovation on cultural and aesthetic values, environmental impact, financial payback time, and user satisfaction. In the energy renovation, the fa\ue7ade, which had been disfigured in an earlier renovation, was recreated to resemble the original architecture. The main questions are: What impact has the recreation of the fa\ue7ade on the environmental payback time in comparison to a more conventional renovation? What are the consequences for the user satisfaction and financial return on investment? The results show that the recreated fa\ue7ade has improved the building’s aesthetics without compromising the environmental benefits. It also resulted in better thermal comfort, which is highly valued by the tenants. The improved aesthetics are also appreciated by the tenants, but to a lesser extent. Financially, the renovation is estimated to be not viable. Results of this study can be applied in the decision-making of similar renovation project

The observed link between urbanization and invasion can depend on how invasion is measured

Aim Cities are thought to promote biological invasions because invasive species are more often introduced in urban areas and because they are more successful in disturbed environments. However, the association is not as strongly supported by the literature as is generally assumed and might depend on how urbanization and invasion are measured. In this study, we test if the type of data used to assess the link between urbanization and invasion can affect a study's conclusions. Location Europe and middle Rhône valley (~5000 km2 in south-eastern France). Method We studied the spatial distribution of the invasive garden ant Lasius neglectus in its current introduced range in Europe and tested its association with urbanization using three measures of invasion (presence-only, presence–absence and population area) and two measures of urbanization (urban/nonurban land cover classification and proportion of impervious surfaces (buildings, road) per spatial unit). Results Based on presence-only data across Europe, L. neglectus occurred in urban areas 10 times more often than expected from a random geographical distribution. However, when controlling for spatial bias in sampling effort with presence–absence data (1870 sampling locations in the middle Rhône valley, France), the occurrence of the species was independent of urbanization. Moreover, the surface occupied by L. neglectus populations was negatively correlated with urbanization. Main conclusions These findings show that the type of occurrence data used to test the link between urbanization and invasion can strongly affect the conclusion of a study. This is particularly concerning because invasion studies often use presence-only data that are likely biased towards cities. Future urban invasions studies must be carefully designed to avoid this pitfall.Peer reviewe

Clinical features of H1N1 2009 infection in critically ill immunocompromised patients

Seasonal influenza virus has been described as an emerging and severe pathogen in immunocompromised hosts. Since the beginning of the 2009 influenza A novel H1N1 pandemic, several series have described the clinical course of the disease in various populations. We report the clinical course of H1N1 2009 infection in 10 immunocompromised patients. Half of the patients received long-term steroid therapy. Disease was characterized by a clinical picture similar to that of non-immunocompromised patients but with prolonged course and higher mortality

Incidence of Postpartum Infection, Outcomes and Associated Risk Factors at Mbarara Regional Referral Hospital in Uganda

Background: There is a paucity of recent prospective data on the incidence of postpartum infections and associated risk factors in sub-Saharan Africa. Retrospective studies estimate that puerperal sepsis causes approximately 10% of maternal deaths in Africa. Methods: We enrolled 4231 women presenting to a Ugandan regional referral hospital for delivery or postpartum care into a prospective cohort and measured vital signs postpartum. Women developing fever (\u3e 38.0 °C) or hypothermia (\u3c 36.0 °C) underwent symptom questionnaire, structured physical exam, malaria testing, blood, and urine cultures. Demographic, treatment, and post-discharge outcomes data were collected from febrile/hypothermic women and a random sample of 1708 normothermic women. The primary outcome was in-hospital postpartum infection. Multivariable logistic regression was used to determine factors independently associated with postpartum fever/ hypothermia and with confirmed infection. Results: Overall, 4176/4231 (99%) had ≥1 temperature measured and 205/4231 (5%) were febrile or hypothermic. An additional 1708 normothermic women were randomly selected for additional data collection, for a total sample size of 1913 participants, 1730 (90%) of whom had complete data. The mean age was 25 years, 214 (12%) were HIV-infected, 874 (51%) delivered by cesarean and 662 (38%) were primigravidae. Among febrile/hypothermic participants, 174/205 (85%) underwent full clinical and microbiological evaluation for infection, and an additional 24 (12%) had a partial evaluation. Overall, 84/4231 (2%) of participants met criteria for one or more in-hospital postpartum infections. Endometritis was the most common, identified in 76/193 (39%) of women evaluated clinically. Twenty-five of 175 (14%) participants with urinalysis and urine culture results met criteria for urinary tract infection. Bloodstream infection was diagnosed in 5/185 (3%) participants with blood culture results. Another 5/186 (3%) tested positive for malaria. Cesarean delivery was independently associated with incident, in-hospital postpartum infection (aOR 3.9, 95% CI 1.5– 10.3, P = 0.006), while antenatal clinic attendance was associated with reduced odds (aOR 0.4, 95% CI 0.2–0.9, P = 0.02). There was no difference in in-hospital maternal deaths between the febrile/hypothermic (1, 0.5%) and normothermic groups (0, P = 0.11)