Emission Savings Research Articles

P0027 The carbon footprint of remote monitoring of IBD patients – a green opportunity for sustainable outpatient care

Abstract Background Climate change is a major public health threat, with healthcare systems contributing 4-5% of global greenhouse gas (GHG) emissions. Inflammatory Bowel Disease (IBD), a chronic and increasingly prevalent condition, demands extensive healthcare resources, making healthcare for this patient population a notable contributor to carbon dioxide (CO2) and other GHG emissions. Remote care offers an opportunity by reducing transport-related emissions through fewer outpatient visits. In this study we aimed to assess the carbon footprint of IBD care and compare the emissions associated with remote versus standard care. Methods A randomized controlled trial involving 909 IBD patients from two academic and two non-academic hospitals in the Netherlands compared telemedicine via myIBDcoach with standard outpatient care for a 12-month period.1 In an explorative analysis, the annual carbon footprint of IBD-related healthcare, expressed as CO2-equivalent (CO2e), was estimated, covering outpatient and inpatient services, diagnostic procedures (i.e., endoscopy, radiology), surgeries, and patient travel (assuming 100% car use).2 Staff travel, laboratory tests, and medication use were out of scope. Emission conversion factors were derived primarily from Dutch literature and supplemented with international sources (Table 1). Results The total annual carbon footprint for all patients was 53,779 kg CO2e (Figure 1), mainly driven by hospitalization (50.6%) and patient travel (29.0%, mean travel distance: 20.3 km). Per IBD patient, the mean annual carbon footprint was 65.5 kg CO2e in the standard care group (n=443) and 56.5 kg CO2e in the remote monitoring group (n=438), saving 9.0 kg CO2e per patient annually. Reduced outpatient visits in the remote monitoring group accounted for most savings, with annual emissions dropping from 21.6 kg CO2e to 14.3 kg CO2e, saving 7.3 kg CO2e per year. Scaling remote care to the 120,000 patients IBD patients in the Netherlands3 could save approximately 878 tons CO2e per year. This is equivalent to the annual carbon footprint of 47 average Dutch households, including housing, transport, clothing, food, and other goods. Conclusion IBD care has a substantial environmental impact. Remote care reduces outpatient visits and achieves notable emission savings, with even greater potential in larger countries than the Netherlands. Implementing remote monitoring with tight disease control in routine care can substantially reduce carbon emissions for IBD and other chronic disease populations.

P0398 Point of Care Intestinal ultrasound – is it the key to reducing the carbon footprint of IBD Care?

Abstract Background Sustainability of IBD care has been identified as a key priority for the coming years by ECCO as part of the REACH strategy. Additionally, the Irish Health Service Climate Action Strategy aims to achieve net-zero emissions by 2050 and provide healthcare that is environmentally and socially sustainable. The STRIDE II consensus discusses new treatment goals in the care of IBD such as endoscopic healing which would require more frequent monitoring. However this poses an environmental burden as one MRI generates approximately 20kg CO2e, 3 times more than a CT scan (7kg CO2e), and 20 times more than an ultrasound (1kg CO2e) and 1 colonoscopy is estimated to generate between 28-55kg CO2e. Decontamination of the endoscope generate a further 11.19 kg CO2e. Point of Care Intestinal ultrasound (POC-IUS) offers a low carbon alternative compared to CT, MRI and endoscopy for disease assessment and monitoring. Aim To calculate the potential reduction in Greenhouse Gas (GHG) emissions from the use of POC-IUS for disease monitoring. Methods A retrospective analysis of all POC-IUS performed over a 12mth period was conducted. We focused on the impact of utilising IUS in the IBD clinic instead of interval MRE or colonoscopy to assess disease activity. The immediate carbon emissions saved as a result of utilising IUS alone was calculated. The long term reduction of carbon emissions over a three year period from using IUS as an alternative tool for disease monitoring was also calculated. Data on patient travel, investigations and associated emissions were collected from the patient health record and calculated on ecotree.green. Results 259 patients were identified who underwent IUS, 92% had Crohns disease. 20% (n=52) of patients had active disease which was followed up by POC-IUS alone. Mean F.Calpro was 495. Consequently, 14 fewer colonoscopies and 43 fewer MRE were performed over the 12mth period due to the immediate assessment offered by IUS corresponding to at least 5460km reduction in travel to and from appointments with an overall reduction in GHG emission of 1,485kg CO2e. Overall, the use of POC-IUS instead of MRE and/or colonoscopy led to an estimated reduction in GHG of 3269kg CO2e. Projecting these results over an interval period where IUS is used as the only primary monitoring tool to assess disease activity showed potential carbon emission savings of 36,531kg C02e.This is equivalent to 15 Round-Trip Flights from New York to London. Conclusion The findings emphasise the role IUS delivered within the IBD clinic might play in reducing the carbon footprint of IBD care. POC-IUS is a low carbon alternative and is a tool in providing a lean care system which are two key principles of delivering a sustainable clinical practice.

Life Cycle Carbon Emissions Savings of Replacing Concrete with Recycled Polycarbonate and Sand Composite

Recent work demonstrated that 50:50 sand-recycled polycarbonate (rPC) composites have an average compressive strength of 71 MPa, which dramatically exceeds the average offered by commercial concrete (23.3–30.2 MPa). Due to the promising technical viability of replacing carbon-intensive concrete with recycled sand plastic composites, this study analyzes the cradle-to-gate environmental impacts with a life cycle assessment (LCA). Sand-to-plastic composites (50:50) in different sample sizes were fabricated and the electricity consumption monitored. Cumulative energy demand and IPCC global warming potential 100a were evaluated to quantify energy consumption and greenhouse gas emission associated with sand–plastic brick and two types of concrete, spanning the life cycle from raw material extraction to use phase. The results showed that at small sizes using Ontario grid electricity, the composites were more carbon-intensive than concrete, but as samples increased to standard brick–scale rPC composite bricks, they demonstrated significantly lower environmental impact, emitting 96% less CO2/cm3 than sand–virgin PC (vPC) composite, 45% less than ordinary concrete, and 54% less than frost-resistant concrete. Energy sourcing has a significant influence on emissions. Sand–rPC composite achieves a 67–98% lower carbon footprint compared to sand–vPC composite and a 3–98% reduction compared to both types of concrete. Recycling global polycarbonate production for use in sand–rPC composites, though small compared to the total market, could annually displace approximately 26 Mt of concrete, saving 4.5–5.4 Mt of CO2 emissions. The results showed that the twin problems of carbon emissions from concrete and poor plastic recycling could be partially solved with sand–rPC building material composites to replace concrete.

The impact of the Bangkok metro expansion via Big Taxi GPS probe data

Urban rail investments in megacities aim to reduce congestion and related externalities. This study investigates the impact of Bangkok’s metro expansion on taxi trips using GPS-based data from 2017 to 2019. A rigorous approach to processing and analyzing the extensive traffic data in a difference-in-differences estimation framework shows that the metro expansion decreases taxi trips by approximately 32.2%, compared to areas not served by the metro system. This effect persists for catchment sizes of 300, 500, and 800 meters and increases over time. Bangkok’s 19 new metro stations result in an annual climate benefit of approximately 0.17–0.34 MtCO2-eq yearly or 0.21–0.42% of Thailand’s transport sector emissions. Excluding private vehicle trips from the analysis, this is a conservative estimate of total climate savings. Multi-decadal CO2 emission savings are valued at around $1 billion, supporting the need for climate funding for transit systems in rapidly growing cities in developing countries.

Comparison of two hybrid systems employing linear Fresnel collector and waste heat recovery based on energy, exergy, economic, and environmental aspects

This research aims to develop a new hybrid system that incorporates a linear Fresnel collector (LFC) and waste heat recovery technology using direct storage tanks (DST) to generate stable and uninterruptible power. Moreover, the proposed hybrid system is assessed in terms of energy, exergy, economic, and environmental factors and is compared to a direct steam generation (DSG) hybrid system. In both systems, the heat recovery system recycles the waste heat of an electric arc furnace's low-temperature flue gases. In the first system, the DST plays a vital role in reducing the solar field's fluctuations to provide a stable heat load for an Organic Rankine Cycle (ORC). The ORC receives continuous thermal energy with a solar multiple of 2.7 and a storage capacity of 16 h, generating an average net power of 1,253.80 kW throughout a full day. The findings show that the DST hybrid system has a 10.50% and 14% thermal and exergy efficiency superiority over the DSG hybrid system, respectively. Upon comparing the two hybrid systems, it is evident that the cost of the generated electricity is approximately 25% lower when using two DSTs. However, the DSG hybrid system shows greater savings in both emissions and production costs of CO2.

Modelling the environmental performance of logistics distribution processes: a business case in the agri-food supply chain

PurposeLogistics practitioners face a significant challenge in meeting local and international regulations and the United Nations' Sustainable Development Goals (SDGs) due to the complexities of measuring and assessing the CO2e emissions of logistics processes. This challenge is pronounced in distribution processes, where the literature currently lacks a structured approach based on existing guidelines and regulations or real-case implementation examples.Design/methodology/approachTo analyse the environmental performance of distribution processes, a model with Visual Basic for Applications (VBA) algorithms compliant with the Global Logistics Emissions Council (GLEC) framework was developed. An integrative review identified key elements for evaluating the environmental impact of distribution processes, leading to model development. The model was validated through a business case in the agri-food supply chain, demonstrating its applicability and enabling the analysis of optimisation scenarios.FindingsThe findings suggest potential savings in CO2e emissions of up to 50% by improving vehicle efficiency and maximising vehicle capacity utilisation. Further savings of up to 30% are highlighted for the business case company by increasing intermodal transport modes use.Originality/valueThis study offers several academic and managerial contributions. On the one hand, it offers a structured approach to assess the environmental performance of the logistics distribution processes based on a comprehensive European standard and enriches the literature by providing an industrial application of GLEC framework guidelines. On the other hand, it empowers logistics practitioners with a model to assess the environmental impact of distribution processes, and it enables an enhanced decision-making process in selecting transport modes to achieve the company’s sustainability goals.

An ex-ante study on the impacts of reduced EU sugar consumption: a sweet mix of health and environmental benefits

This paper estimates the health and environmental benefits from reducing sugar intake in EU households. A CGE model is modified by linking probability density functions of body mass index for EU populations to a complete demand system with nutrition accounting. Following the WHO recommendation, sugar intake is reduced to 10% of total dietary energy intake, whilst two further scenarios explore more ambitious targets of 7.5% and 5%. This dietary transition leads to a relative reduction in overweight and obese EU adults of between 8 and 15 million by 2050, with potentially significant health gains in Scandinavia. Environmental ‘footprints’ reveal relative land and emissions savings of up to 56m2 and 20 kgCO2e per capita per year by 2050. With scientific evidence supporting a virtuous circle of improved health, higher wages and increased macroeconomic performance, the reported negative impacts on economic indicators in this study could be reversed through targeted redistributive policies.

Potential impacts of optimised care pathways on carbon impact of anaesthesia consultation-A monocenter prospective study.

Global warming presents major public health challenges, with healthcare transportation significantly contributing to carbon dioxide equivalent emissions (eCO2). While the greenhouse effects of anaesthetic gases are well-documented, the eCO2 of pre-anaesthesia consultations remains underexplored. This study aims to evaluate and propose strategies to reduce the carbon impact of these consultations at a Tertiary University Hospital. In a prospective, observational study over one month, data were collected from patients attending pre-anaesthesia consultations. ECO2 emissions from transportation and electricity were calculated. To reduce emissions, several modifications to the care pathway were investigated, including teleconsultation, remote consultation, grouping of consultations, carpooling, and the promotion of public transport. The effects of current and optimised care pathways were then compared. Data from 213 patients showed that 75% attended the hospital solely for pre-anaesthesia consultations, mostly by car (82%). The mean eCO2 per consultation was 22.4 kgCO2 (95% CI: 14.6-30.2). Implementing optimisation strategies in 65% of cases could reduce emissions to 5.6 kg CO2 (95% CI: 0.2-10.9) per consultation, leading to a 74% reduction and an annual saving of 274 t of eCO2. Our study highlights the potential for significant reductions in the eCO2 of pre-anaesthesia consultations. The adaptation of the care pathway would largely involve grouping consultations and developing teleconsultations. These potential savings in greenhouse gas emissions are in the same order of magnitude as not using desflurane in the operating theatre and could be the next step towards greener anaesthesia.

Life cycle analysis of a solar photovoltaic system in a Philippine university

Abstract Renewable energy sources have been growing in popularity because of the Republic Act 9513, also known as the Renewable Energy Act 2008. With these, various universities in the Philippines have already installed solar photovoltaic (PV) systems. However, details such as carbon emissions reduction and the efficiency of PV systems in Philippine universities still need to be included as baseline data for policy formulation and sustainability. This study aims to evaluate the solar PVs installed at Saint Louis University as part of its climate change advocacy. The environmental Life Cycle Assessment (LCA) approach was conducted through the OpenLCA software with the Ecoinvent database. Results showed that the PV panels installed in the university are economically and environmentally beneficial, wherein the installed panels’ break-even point and cost-benefit ratio are 7 years and 4.5, respectively. Through the cradle-to-grave analysis from manufacturing, transportation, installation, operation, and recycling, the solar PV system yielded an annual emission savings of 278,369 kg of CO2 equivalent. Moreover, the GHG emission payback period was only 2.22 years, with a 93% GHG reduction from utilizing solar PV systems instead of coal-fired power plants. With the summarized results of LCA, this paper hopes to contribute to the solar energy data on Energy Payback Time (EPBT) and GHG emission rates.

Modeling and energy management of hangar thermo-electrical microgrid for electric plane charging considering multiple zones and resources

Achieving net zero goals by 2050 is driving an energy transition towards clean electrical energy. Consequently, many initiatives have been proposed aiming to reduce carbon emissions in the building and transportation sectors, focusing, for instance, on the implementation of efficient heating and cooling systems based on heat pumps and the use of electric planes. Microgrids can effectively integrate thermal and electrical energy resources and loads to satisfy customer demands while providing technical, economic, and environmental benefits. Thus, this paper proposes the implementation of a model of a hangar microgrid and its Energy Management System to optimize the dispatch of resources of such thermo-electrical airport grid, using a Model Predictive Control approach to address uncertainties, and including a detailed building thermal model, heat pump modeling for the heating and cooling systems, and battery degradation. The proposed mathematical model of the Energy Management System is applied to a model of a microgrid being developed for a hangar at the Waterloo Wellington Flight Centre in Ontario, Canada, taking into account the specific characteristics of the microgrid’s components, the expected energy consumption of the equipment and the electric plane used for pilot training based on field measurements, and multi-room temperature control requirements, seeking to ensure a reliable and cost-effective operation, while considering the occupants’ comfort in different spaces. The results indicate that the proposed Energy Management System model, featuring multi-room temperature control through multiple thermal resources, can achieve significant savings in operational costs and CO2 emissions compared to a scenario where the microgrid is not deployed and another where a single-room building thermal model with a single heat pump is included.

A comparative analysis of car fleet efficiency evolution in Europe and Australia insights on policy influence

Regulators worldwide introduce measures to improve energy consumption and reduce greenhouse emissions of road vehicles. The present study focuses on the impacts of passenger car carbon dioxide (CO2) and fuel efficiency measures, attempting to evaluate their effectiveness using vehicle and fleet modelling. To obtain a robust counterfactual result, two regions are compared as a case study: the European Union (EU), where CO2 emissions have been regulated for over fifteen years, and Australia, a region that recently introduced such a policy element. The average difference in the certified CO2 emissions of new cars registered in the two regions increased from 50 g/km in 2018 to 60 g/km in 2021 due to accelerated electrification in the EU. To demonstrate the importance of mandatory targets, a sensitivity analysis of the 2020 EU registrations showed that lower by one-third sales of zero and low-emission vehicles (Z-L-EVs) would have resulted in seven out of ten manufacturer pools failing to meet the 2020 target of 95 g/km. The simulation framework was validated against certified values of 2021 registrations and was subsequently used to calculate real-world fleet performance to quantify the actual emissions savings. The real-world CO2 emissions in the registered fleets for 2021 were estimated to be 143 g/km and 204 g/km, for the EU and Australia, respectively. With these results as a reference, the share of ZEVs required to meet the targets set in both regions is calculated: 51% of the new registrations in 2030 in the EU for achieving 49.5 g/km, and 60% in Australia for recently set target of 58 g/km for 2029. The respective calculated average fleet-wide real-world tailpipe CO2 emissions were estimated to be 66 g/km (EU) and 77 g/km (Australia). As a last step, the study discusses the application of similar tools and analysis in the design of future policies.

Towards Sustainable Corrosion Protection: An Investigation into Ecofriendly Sol-Gel Conversion Coatings for AZ61 Magnesium Alloy

The sustainability and corrosion protection are two critical factors in the field of materials for mobility. Lightweight alloys, such as the AZ61 magnesium alloy, are gaining recognition for their potential applications in the aerospace, automotive, and marine industries. The use of these alloys not only contributes to weight reduction and consequent fuel and CO2 emission savings, but also opens up new possibilities for innovative design and performance enhancements [1].In search for sustainable corrosion protection, we have focused our research towards the development of environmentally acceptable sol-gel coatings enriched with green corrosion inhibitors. These coatings not only prolong the lifespan of materials made with the AZ61 magnesium alloy but also align with the commitment to environmental stewardship, offering promising prospects for effective corrosion protection [2].The sol-gel coatings were synthesized using tetraethyl orthosilicate (TEOS) and 3-(trimethoxysilyl)propyl methacrylate (MAPTMS) as precursors. Four different organic inhibitors - L-cysteine (CYS), N-acetyl-cysteine (N-A-CYS), curcumin (CUR), and methylene blue (MB) - that are environmentally friendly, non-toxic, inexpensive and contain S, N heteroatoms, O and/or OH groups and/or conjugated double bonds - were selected for the study. These compounds were incorporated into the sol as dopants. A set of sols was doped with a common corrosion inhibitor, benzotriazole (BTA), for comparison purposes. The resulting sols were processed and deposited on AZ61 substrates using the dip-coating technique.The thickness of the coatings was determined using the interference fringe method in the ultraviolet-visible and near-infrared ranges [2]. Transmission spectra of coated glass samples were also obtained to determine the wavelength of each coating at 50% transmission. The hydrophilic character of the coatings was characterized by measuring the contact angle.To study the corrosion behaviour of the coated surfaces, weathering tests, based on a variation of the ISO 11130 [3], were conducted. The samples were weighed before and after the corrosion test to examine weight variations. Optical microscopy provided insights into the surface of the samples both before and after the corrosion test. Detailed observations of the surface morphologies of the samples were made using SEM, and EDX analyses were performed to verify the compositions of the compounds found. Confocal Raman microscopy was also employed to provide accurate compositional information at a local microscale level, shedding light on the compounds formed considering the chemical strategies developed in the protective sol-gel coating [4,5]. The study was concluded by applying global and localized electrochemical impedance spectroscopies (EIS, LEIS) to study the corrosion protection behaviour of the sol-gel coatings during immersion tests in 0.006 M and 0.6 M NaCl aqueous solutions.As a concluding remark, it is noteworthy that in several of the tested sol-gel coatings, micro-cracks and defects formed during weathering tests self-seal, thanks to oxy-hydroxides adhering to the Mg alloy substrate. Additionally, in response to the corrosive anions of the aqueous solution, due to the release of the organic inhibitors that were nanoencapsulated in the sol-gel matrix, an active corrosion protection is initiated beneath the coatings. In conclusion, the tested eco-friendly coatings, applicable by dip-coating or spray at room temperature, offer potential for broad industrial use and economic feasibility, suggesting industrial scale-up feasibility. Funding Sources This work has been supported by the Projects PID2022-139920OB-I00, PID2021-126323OA-I00 and TED2021-129688-CT21 (Ministry of Science, Innovation and Universities, MICINN, Spain). The team extends its acknowledgements to Miguel Romero Martín of the ECORR Group for his help with impedance measurements and result analysis.

Development of an optimization-based methodology for subsidy programs of residential buildings

The success of the energy transition in the building sector depends not only on the technical feasibility but also on the economic viability of energy modernization measures. Subsidy programs for building owners and energy prices significantly influence this economic viability, thereby affecting the adoption of low-emission energy systems in buildings. In order to achieve national climate targets, an efficient allocation of funds to modernization measures that reduce building emissions is necessary. In this context, the question arises as to how funds should be used from the perspective of a funding agency in order to achieve a cost-effective steering effect with regard to the achievement of climate goals. Against this background, this study presents a novel two-stage optimization approach to determine cost-effective subsidy strategies. In the upper level, the government aims to reduce subsidies to achieve CO2 targets. In the lower level, individual building models optimize their total costs by upgrading the heat conversion technology or insulating the building envelope. To achieve feasibility, the lower model is implemented into the upper model as a discrete set, resulting in a single-stage problem. The model determines the minimum subsidy rates that make the purchase of the technologies and measures profitable for the building owner, depending on a CO2 target set by the government. The results show that the introduction of subsidy programs has a significant steering effect on emissions savings. The targeted promotion of low-emission heat supply technologies, such as heat pumps, with up to 40 % subsidy quota in combination with subsidies for insulation measures significantly contributes to their installation in existing buildings. This contributes to the achievement of climate protection goals, especially when considering the future expansion of renewable energies in the electricity mix. With the current cost and emission factors of pellets, the promotion of pellet heating can further contribute to strong emission savings. The approach presented highlights the critical role of economic incentives in guiding emission reductions and achieving climate change goals.

Impact of layout strategy and sector-coupling on the multi-criteria assessment of energy technology concepts for residential buildings

Energy system transformation needs decentralisation, decarbonisation and sector-coupling. Local energy systems are often customarily designed using heuristics for the technology layout. However, optimisation of the technology layout and operation is considered a powerful tool. Therefore, we investigate the influence of an optimised layout and the coupling of the electricity and heat sector on economic, ecological and technological criteria. The criteria comprise the annual costs, CO2 emissions, and the energy performance in terms of self-sufficiency and self-consumption. We consider typical energy technology concepts with fixed technology combinations for the heat and electricity supply of residential buildings. The optimisation is performed using a Mixed-Integer Linear Programming under the objective of minimal costs. The assessment is done using the Analytic Hierarchy Process. An optimised layout is found to reduce costs at the expense of emissions and energy performance. In comparison to the heuristic layout, especially the storage sizes differ among the layout strategies. Sector-coupling leads to CO2 emission savings and a higher self-consumption of the PV energy produced within the system. The multi-criteria assessment reveals higher performance scores for heuristically laid out concepts under a local sensitivity analysis of the criteria weights.

Surrogate-assisted optimization under uncertainty for design for remanufacturing considering material price volatility

Remanufacturing is a well-established end-of-life (EOL) strategy that promises significant savings in energy and carbon emissions. However, the current design practices are not remanufacturing-inclusive, i.e., the majority of products are designed for a single life cycle. As a result, potential products that can sustain multiple life cycles are deprived of additional benefits of being designed for remanufacturing, such as reduced material usage, lower cost, and improved environmental impact. Moreover, the uncertainty in design, material selection, and economics are not considered to produce remanufacturable designs. Accordingly, this research proposes a design for remanufacturing (DfRem) framework that accounts for design uncertainty and material price volatility. The framework systematically explores the design space, performs design optimization under uncertainty, followed by topology optimization to provide additional mass savings, and finally, a price volatility analysis for plausible design material choices. The candidate designs are evaluated based on their design mass, material price volatility, failure mode characteristics, carbon footprint, and embodied energy impacts. The proposed framework's utility is demonstrated via the use of an engine cylinder head case study subjected to thermo-mechanical loads along with fatigue and wear failure. Considering grey cast iron and aluminum alloy as the design material choices, it was found that the cast iron design reduced the initial design mass by 6% as opposed to a 5% decrease for aluminum. On the other hand, about 8% area of the cast iron design failed due to fatigue, compared to 3% for aluminum. We further observed that although the aluminum design provided better mechanical performance than the cast iron design, this material was more expensive and volatile in price.

An agile life cycle assessment for the deployment of photovoltaic energy systems in the built environment

BackgroundIn the context of urban energy transition, photovoltaic (PV) systems play an important role in electricity generation. However, PV technology has some environmental drawbacks that also need to be acknowledged and managed. Life cycle assessment (LCA) is widely used to assess the environmental impacts of systems, but LCA is very complex to perform. Therefore, this research work presents a proof of concept for a parameterized LCA tool for grid-tied photovoltaic systems in urban areas that allows non-experts in LCA to obtain LCA results reliably and quickly.ResultsThe resulting methodology is an integration of three preexisting tools: PVGIS, Brightway and Ecoinvent, plus a Breakeven point analysis. The first step of the approach consists of identifying the main parameters of photovoltaic systems: geographical, technological, and temporal. Once the non-expert practitioner sets the influential parameters, the tool assesses the greenhouse gas emissions over the life cycle of the PV panels per unit of supplied electricity, allocates the emissions per component, and calculates the point at which the avoided emissions compensate for those produced by the power system. The algorithm strives to find the optimal PV system configuration to reduce the environmental impact, providing decision-making support for promoters and policymakers in the context of the urban energy transition. Two case studies are presented to illustrate the proposed method’s applicability and benefits.ConclusionsThe production of PV panels was confirmed as the main source of emissions in this kind of installation. The reasons are analyzed, allowing for improved design. Furthermore, the estimated break-even point where savings of conventional electricity offset emissions shows the influence of the parameters on the system’s environmental performance.

Study on steam energy efficiency enhancement, cost management and CO2 emissions in the food industry

Malaysia's energy intensity per unit GDP has been increasing since the 1990s, leading to the government's efforts to promote energy efficiency via policies and initiatives such as Energy Performance Contracting (EPC). Additionally, the industrial sector in Malaysia consumed 28 % of total final energy in 2018, placing it as the country's second-largest final energy consumer [1]. This case study focuses on improving energy efficiency in the steam system of an existing plant in the food industry in Malaysia. This work was performed in collaboration with a local Energy Service Company (ESCO) to study the existing steam system, recognize its process requirements and constraints and consequently propose and evaluate retrofit opportunities. These opportunities were evaluated across 3 performance parameters (power output or energy savings, cost savings and CO2 emissions savings). Simulations were performed using the Steam System Modeler Tool (SSMT). The study found that Combined Heat and Power (CHP) was not feasible due to a combination of low steam pressure and flowrate available in the system. However, the study also found that improving condensate recovery coupled with condensate flashing from the high pressure to low pressure header offered the highest increments in overall performance.

Gasification of agricultural residues to support the decarbonization of the transport sector via electricity generation: a case study

Abstract The gradual electrification of transport, particularly private cars, requires widespread electricity availability and potential peak demand in rural or underdeveloped regions could strain the existing electricity network. Therefore, exploring distributed electricity generation is crucial to reduce grid demand and can be an opportunity to promote low-carbon technologies. In this research work we analyze the potential contribution of a biomass gasifier, fueled by vine prunings, in supplying electricity to a local site for electric vehicles charging. The performance of the system is assessed from a technical, economic and environmental point of view. In particular, the specific equivalent CO2 emissions of the system are compared to the alternative emissions of the national power grid, considering the estimated charging profiles based on available patterns from real case studies that incorporate different users’ behaviours and preferences. The electricity produced by the gasifier has a calculated supply chain carbon intensity of 134 gCO 2e · kWh −1, which can be sharply reduced to -34 gCO 2e · kWh −1, indicating a carbon-negative process, when the carbon sequestration of the co-produced biochar is considered. These figures should be evaluated against a weighted average carbon intensity of the national electricity mix equal to 384 gCO 2e · kWh −1 in 2018, while the same figure for 2030 ranges from 141 gCO 2e · kWh −1 to 226 gCO 2e · kWh −1 depending on the future scenario that is considered. The economic assessment estimates payback times between 6 and 8 years with an average utilization factor of the charging station equal to 14% and a charging price equal to 0.62 €/kWh. In addition to the emission savings that are obtained, this approach could generate further positive effects on the territory: a) the production of electricity allows rural areas to establish their sustainable electric transportation network, reducing their marginalization; b) the production portfolio of farms or agricultural consortia is diversified; c) create a carbon-negative recovery chain for lignocellulosic waste and offers a sustainable solution for their disposal. The results of this analysis can be of use for other researchers dealing with similar topics, and for policymakers that aim to compare available solutions for the decarbonization of the transport sector.

Solar-Powered Refrigeration for Sustainable Refrigerated Transport

Abstract Solar-powered refrigeration systems offer a feasible and promising solution for enhancing the sustainability of refrigerated transportation. This paper provides a comprehensive overview of the design and construction of a solar-powered refrigeration unit tailored for a refrigerated van, featuring photovoltaic (PV) panels mounted on the rooftop of the refrigerated box. The key components and operational mechanisms of the unit are also highlighted. The study reports on five preliminary experimental tests conducted to validate the feasibility and efficacy of a transport refrigeration unit (TRU) powered by solar energy. These tests demonstrate the impact of the PV solar system on the energy balance of the refrigerated unit under various environmental and operational conditions. The results indicate that the photovoltaic system enables autonomous operation of the refrigeration unit for 2.5 hours at a set point of -18°C (suitable for frozen products) and over 5 hours at +4°C (suitable for fresh products), assuming afternoon deliveries starting at 14:00 with climatic conditions typical of June and July in Fisciano, Salerno, Italy. These findings support the feasibility of sustainable regional and inter-regional transportation. The study also evaluates the effect of different starting times, revealing an increase in the duration of autonomous operation by up to 35% for transportation at 0°C when the start time is shifted from 14:00 to 11:00. Furthermore, the research assesses emission savings, identifying reductions between 4.1 and 4.4 kgCO2,e per delivery at set point temperatures of -18 °C and +4 °C, respectively. This range is even wider when considering earlier starting time (up to 5.4 kgCO2,e per delivery in the tests performed). This underscores the significant potential of solar-powered solutions in advancing the decarbonization of the cold chain. This research aims to inform policymakers and technology developers about the potential of deploying solar-based solutions in the refrigerated transport sector.

Remanufacturing construction and demolition waste and incineration ashes into eco-blocks: Quantitative sustainability assessment

This study performed a sustainability evaluation of a proposed business for remanufacturing concrete materials from construction and demolition waste (CDW) and ash from the combustion of municipal solid waste (MSW) to produce eco-blocks for construction applications. Six possible industrial remanufacturing alternatives are proposed based on commercially available industrial machinery and their economic sustainability was compared by a cost and profit feasibility study. Furthermore, the technical feasibility was evaluated by considering the maturity of the selected machinery based on the relationships among the cost–productivity, power–productivity, and number of workers–productivity pairs. The proposed remanufacturing business achieves a maximum profit of 17,643 USD/day with a minimum remanufacturing cost of 30.65 USD/t for the production of 529 t of eco-blocks in an 8-h factory shift. A quantitative environmental sustainability assessment was performed using the remanufacturing cost, profit, concrete savings, energy savings, CO2 emission savings, and eco-cost savings as criteria based on demographic statistics from the literature for current and predicted CDW and MSW generation. CDW and incineration ash are widely available, so the proposed process is viable worldwide. Based on the technical, economic, and environmental sustainability results, a final sustainability index of 0.874 was calculated, which exceeds literature thresholds for a sustainable business, indicating that the proposed eco-block remanufacturing process has the potential to generate substantial profits, while positively contributing to reducing waste and energy usage by recovering valuable resources and producing value-added products. The remanufactured eco-blocks are prepared in the same way as typical concrete blocks and can be used for all of the same residential, commercial, and industrial construction and landscaping applications. The remanufactured eco-blocks have several advantages over typical concrete blocks, including a much lower manufacturing cost (∼50 % lower), significant environmental and resource savings by avoiding the use of new sand and gravel resources, and improved mechanical properties.