Emission Savings Research Articles

Biogas and biohydrogen for net zero cooking and transportation in Bhutan

Agricultural biomass is a promising renewable energy material for Bhutan to support net zero transition of its cooking and transport sectors. In this study, crop residue and animal manure biomass-based biogas and biohydrogen potential of Bhutan are assessed at district and regional levels using a spatial framework. Existing energy demand of the cooking and transport sectors and associated greenhouse gases (GHGs) emissions are also estimated spatially. To analyze the net zero transition potential in the cooking and transport sectors, current energy situations of the sectors are compared with biogas-based cooking and biohydrogen-based transportation. It is observed that, annual biogas potential of Bhutan is 105 million cubic meter (mcm), equivalent to 2091 tera joule (TJ) energy. The potential is higher than the current cooking energy demand of 1230 TJ. At individual district level, 16 out of 20 districts can 100 % substitute LPG and firewood with biogas to support net zero transition of the cooking sector. Estimated annual GHGs emissions from the cooking sector are 102,089 t CO2eq. Transitioning to biogas-based cooking would provide significant GHGs emissions savings benefits for Bhutan. For example, annual emissions savings of 93,443 t CO2eq could be achieved through crop residue biogas-based cooking. Similarly, estimated biohydrogen potential (111 mcm, equivalent to 1194 TJ) can meet 35 % of current transportation energy demand (3353 TJ) of Bhutan. Full realization of the biohydrogen potential (1194 TJ) could provide annually 27,187 t CO2eq emissions savings in the transport sector of Bhutan. The findings of the present research could be useful for net zero transition of cooking and transport sectors of Bhutan. Thus, by leveraging the potential of biogas and biohydrogen, Bhutan can accelerate net zero transition and circular growth.

Transitioning the apparel supply chain to circular economy: a quantitative approach

This paper aims at exploring the potential of implementing circular economy in global supply chains, from the economic and environmental perspectives. The scientific community has revealed a growing interest in deepening the topic of global circular supply chain management, although literature based on quantitative studies is almost scant. This paper aims at filling some significant gaps by demonstrating that a transition to a circular supply chain not just leads to savings of emissions and natural resources, but it is also a driver to boost profitability. To this purpose, a real-life case-study of a global supply chain in the apparel industry has been modelled and simulations are conducted to quantitatively evaluate the benefits of three different circular supply chains implementing Reuse, Remanufacture and recycled processes over a traditional linear configuration. Results are obtained through a robust design of experiments and are validated via ANOVA test. According to the findings, a circular supply chain configuration can boost profitability by more than 5%, reducing at the same time the consumption of environmental resources by more than 10%.

Energy and cost savings of cool coatings for multifamily buildings in U.S. climate zones

While cool coatings have recently received much attention for building applications, their impact on building energy consumption strongly depends upon climatic conditions. Herein we evaluate the energy, cost, carbon, and interior comfort impact of cool coatings applied to a residential multifamily building across 32 climate zones in the United States by applying advanced cool coating properties to established building energy models. The model not only considers promising cool coating properties based upon recent experiments but also an ideal cool coating. Our calculations show that the ideal cool coating can achieve annual cooling energy savings of up to 6.64 kWh/m2 (Phoenix, AZ), annual net utility cost savings up to $1.16/m2 (Brawley, CA), and net annual carbon emission savings up to 7.7 % (Phoenix, AZ). We also estimate the change in interior temperature for buildings without space cooling systems and show that cool coatings make buildings in the warmest climate zones in the U.S. without space cooling more comfortable by 30 % to 50 % on a cooling degree days basis. Using analysis of variance, we examine the statistical relationships between building performance metrics and climatic parameters. The presented methodology enables evaluation of cool coating application to buildings in various climate zones across the world.

A framework for evaluating urban solar adoption considering economic and environmental priorities of project owners

In recent years, the utilization of photovoltaic (PV) solar systems in built-up regions have received more attention due to global warming issues and the need to mitigate the dependence on fossil fuels in buildings. In this context, it becomes critical to comprehend the economic and environmental implications of roof-installed PV systems for project owners looking to expand their usage. Thus, there is a need to develop a framework for optimizing rooftop solar PV systems in urban regions considering the economic and environmental aspects with regard to the PV project owners’ priorities, in addition to the energy-saving context, which was addressed in previous studies. Therefore, this study develops a search space optimization method to find the optimum layout of PV modules on roofs of buildings in urban regions, considering solar PV project owners' economic and environmental priorities. Payback time (PBT) and CO2 emission savings are considered for the economic and environmental criteria calculations, respectively. The results show the significance of owners’ economic and environmental priorities toward PV module arrangement on roofs. Instead of having an entire economic priority, having a 25 % environmental priority enhances annual PV system output and CO2 emission savings about 1.5 times with almost the same PBT.

Unlocking the potential of the bioeconomy for climate change reduction: The optimal use of lignocellulosic biomass in Germany

AbstractThe concept of a circular bioeconomy has become a new economic leitmotif for reducing greenhouse gas (GHG) emissions. Its central narrative rests on the idea of replacing fossil resources with biobased ones for a broad spectrum of products including, for example, heat, electricity, fuels, plastics, or chemicals. Yet, the amount of available bio‐resources is limited, rendering some technologies successful while leaving behind others. Lignocellulosic biomass (LBM) is a key resource already used on a large scale for heating purposes or electricity production and increasingly for the production of chemicals and biofuels. Because market mechanisms do not necessarily drive a cost‐optimal use with respect to their GHG‐reduction potential, a new bi‐objective linear optimization model under long‐term scenarios was developed for Germany accounting for competition with non‐biobased technologies. In the biofuels and biochemicals sectors, multi‐output processes that address industrial symbiosis and fossil references are used to compute profits and GHG emission savings of biobased products. However, in the absence of a reference for heat, a detailed representation of the heat sector is used in which heat demand for 19 subsectors is met, thus deriving costs and emission savings endogenously. When explicitly accounting for GHG emission reduction targets, biomass is optimally used in high‐temperature industries whereas heat pumps dominate in building heat. Because of the optimal use of biomass in industrial usage, subsidies for biomass heating are found to be inefficient in the building sector. Catalytic hydropyrolysis to produce biogasoline and biodiesel using LBM dominates the production of biofuels while biochemicals—strongly depending on oil price developments—will become competitive on a large scale after 2030.

Optimization of an off-grid PV/biogas/battery hybrid energy system for electrification: A case study in a commercial platform in Morocco

The use of hybrid renewable energy systems is growing as a viable option for clean power generation, fueled by the increasing demand for sustainable energy sources and the need to reduce carbon emissions. In this context, this paper evaluates the optimal configuration, as well as the economic and environmental performances of a hybrid solar PV/biogas/battery energy system designed to provide electricity to a commercial platform in Berkane- Morocco. The optimization model aims to determine the optimal capacity of renewable energy systems achieving the most cost-effective levelized cost of electricity, reducing greenhouse gas emissions, and utilizing locally available renewable energy resources. The model was developed using HOMER software incorporating real-measured data for electricity demand, solar irradiance, and biogas availability. It was found that the PV/biogas/battery combination is very optimal in terms of cost and emissions savings in comparison with the use of only one source of power generation. The optimal design of the energy system results in 231 kW of PV modules, 170 kW biogas generator, a 140-kW converter, and a 201 kWh Li-Ion battery park. The optimization results in an LCOE of 0.280 $/kWh; Moreover, the proposed system would save almost 40 % of carbon dioxide (CO2) emissions in comparison with only biogas system. A sensitivity test has been performed, showing that the proposed hybrid system is sensitive to capital subsidies and discount rates. This study demonstrates the economic viability and environmental benefits driven by the integration of the hybrid of PV/Biogas/Battery system in Morocco, making it an attractive alternative for future sustainable development.

Using different transport modes: An opportunity to reduce UK passenger transport emissions?

In 2022, transport accounted for around one third of UK territorial emissions. Many decarbonisation pathways include modal shift as a possible way of reducing passenger transport emissions. Yet, the mitigation potential of modal shift often depends on generic behavioural assumptions rather than the technical feasibility for using different transport modes. Here travel microdata from the UK is used to systematically assess which trips could use more efficient transport modes, establishing a theoretical maximum for how much modal shift could take place with no reduction in mobility. Compared to current passenger transport use, emissions could be reduced by about 30% by changing the transport modes used for personal travel. This is possible if car use is reduced by approximately 27% and mainly replaced by trains. Further emissions savings are possible by increasing bicycle and motorcycle availability, increasing capacity of coach and surface rail, and increasing the time typically spent travelling.

Feasibility assessment of remanufacturing waste sheet steel into angle mesh steel

AbstractAs a better alternative to the energy‐intensive process of recycling waste sheet steel (WSS) from the exterior components of end‐of‐life vehicles to produce new steel, the feasibility of remanufacturing WSS into angle mesh steel (AMS) for construction applications is evaluated. A remanufacturing unit with a capacity of 1278 m2/day of WSS (30,000 vehicle/year) was evaluated using a triple‐bottom‐line sustainability analysis of the technological, economic, and environmental feasibilities by hybrid defuzzification–curve‐fitting, solid‐waste recoverability management, and weighting methods. Based on the remanufacturing productivity, an economic feasibility index was calculated considering the sales potential and profit, while the energy and CO2 emission savings were used to evaluate the environmental feasibility. The technical feasibility considered machine parameters and topological properties of the WSS. The Volkswagen Passat has the best remanufacturability of 200 analysed vehicle models. Remanufacturability indexes of 0.61 and 0.86 were calculated, giving remanufacturing efficiencies of 58%–82%. All feasibility indexes exceed literature thresholds, indicating that the proposed remanufacturing process is a sustainable business strategy and contributes to the United Nations Sustainability Goals of climate action; responsible consumption and production; no poverty; and industry, innovation, and infrastructure.

Theoretical and experimental evaluation of electric coolant pump benefits in real driving cycles

Engine thermal management is a promising option to reduce fuel consumption and harmful emissions of Internal Combustion Engines. This is particularly suitable to support the transition towards a carbon-neutral transportation sector, considering that the role of combustion engines is expected to persist in the near and medium future. In this study, a prototype pump electrically actuated was compared to a mechanical pump of a downsized gasoline engine that propels a real vehicle. In the first phase of the analysis, the cooling circuit was tested from a hydraulic point of view on all its branches using an engine mounted on a bench equal to that working on the vehicle. The hydraulic circuit was fully characterized via pressure transducers and flow meters in all branches for different thermostat lifts, representing different coolant temperatures. On the same bench, the OEM pump and an electrically actuated one, suitably redesigned on an operating point more representative of the real operating conditions, were tested. A vehicle propelled with the same tested engine (having a conventional mechanically actuated pump) was run on the road following three different driving cycles. The engine revolution speeds were registered, as well as the temperature of the cooling fluid. The electric and mechanical pumps were compared using the performance maps previously obtained. The electric pump speed was set to deliver the same coolant flow rate as the OEM pump, following the same sequence of thermostat lifts. The results show that a 60 % average reduction of the pump energy consumption is possible, leading to an average specific CO2 emission reduction of 1 g/km. This result is even more relevant during urban driving, with emission savings hitting 2.5 g/km.

The potential role of biomethane for the decarbonization of transport: An analysis of 2030 scenarios in Italy

This paper aims at evaluating the best allocation of potential biomethane generation for the decarbonization of the transport system, presenting a case study in Italy. The country has some peculiar features, such as several operating biogas plants, additional potential feedstock for biogas/biomethane generation, a well-developed natural gas network and established relevant natural gas uses in different final sectors, including transport. Based on current estimates for sustainable biomethane potential by 2030, ranging from 2.3 to 7.6 billion cubic meters depending on the scenario, the analysis compares technologies for the generation, distribution and final use of biomethane. The results of the analysis confirm the potential interesting contribution of biomethane in decarbonizing the Italian transport system: a billion cubic meters of biomethane can lead to 2.33–4.37 MtCO2e savings, depending on the feedstock mix and the application. On a national basis, annual climate emission savings in 2030 range from 10.0 to 26.7 MtCO2e, depending on the scenario. Additional 3.1–8.1 MtCO2 of emissions can be avoided if the CO2 captured during the biomethane upgrading can be stored or reused. The proposed methodology could be used to extend the analysis to other countries, and to the European context.

The effects of dietary changes in Europe on greenhouse gas emissions and agricultural incomes in Ireland and Denmark

Livestock farming is one of the main sources of greenhouse gas emissions. In Europe, the agricultural sectors of Ireland and Denmark are the most livestock-intensive. Based on a scenario analysis using a computable general equilibrium model, we estimate the effects of dietary changes toward the recommendations of the EAT-Lancet Commission in Europe on the agricultural sector of Ireland and Denmark. Our results show that full adoption of the diet reduces agricultural emissions, particularly methane, with potential emission savings of 26.4% or 5.4 Mt CO2-equivalent in Ireland and 21.7%, or 1.9 Mt CO2-equivalent in Denmark. Global agricultural emissions decrease by 2.4% or 193.7 Mt CO2-equivalent. However, incomes in livestock farming fall. This is offset to varying degrees by gains in horticulture and trade dynamics, leading to different outcomes across regions. Policymakers should promote plant-based diets and monitor export dynamics to achieve effective emission reductions. Additionally, methane mitigation strategies should be integrated into climate plans. This study highlights the need for further research on country-specific environmental impacts and trade-offs associated with dietary changes.

Waste heat recovery integration options for commercial bakeries in a thermo-economic-environmental perspective

In commercial bakeries, a substantial amount of heat is exhausted which is not only a waste of useful resource, but also contributes to higher fuel consumption and carbon emissions, if not recovered. In this study, waste heat from a single oven is considered and five potential heat recovery options are investigated in a techno-economic-environmental perspective to provide essential results for integrating an appropriate technology for waste heat recovery in the commercial bakeries sector. Waste heat recovery options were selected considering the temperature profile, the waste heat source, quality and quantity of heat and the heat energy demand for the various processes in commercial bakeries. Thermodynamic, economic, and environmental models are developed to assess the heat recovery performance, cost savings and emission reduction at both design and off-design conditions. Results show that up to 286 kW of waste heat can be recovered and reused in the case of air pre-heater, which can save up to 161.93 t/year of natural gas and an equivalent cost and emission savings of $ 93,594/year and 412.5 tCO2e/year, respectively. Moreover, the earliest payback period of 0.77 years was estimated for the air pre-heater option with an estimated capital investment cost of $71,631, whereas a maximum payback period of 4.59 years was estimated for the electricity generation by the organic Rankine cycle having an estimated capital investment cost of $304,040. These results reveal that air preheating is the most energy-efficient and cost-effective option to recover the waste heat from the ovens in the bakery industry.

Climate vs Energy Security: Quantifying the Trade-offs of BECCS Deployment and Overcoming Opportunity Costs on Set-Aside Land.

Bioenergy with carbon capture and storage (BECCS) sits at the nexus of the climate and energy security. We evaluated trade-offs between scenarios that support climate stabilization (negative emissions and net climate benefit) or energy security (ethanol production). Our spatially explicit model indicates that the foregone climate benefit from abandoned cropland (opportunity cost) increased carbon emissions per unit of energy produced by 14-36%, making geologic carbon capture and storage necessary to achieve negative emissions from any given energy crop. The toll of opportunity costs on the climate benefit of BECCS from set-aside land was offset through the spatial allocation of crops based on their individual biophysical constraints. Dedicated energy crops consistently outperformed mixed grasslands. We estimate that BECCS allocation to land enrolled in the Conservation Reserve Program (CRP) could capture up to 9 Tg C year-1 from the atmosphere, deliver up to 16 Tg CE year-1 in emissions savings, and meet up to 10% of the US energy statutory targets, but contributions varied substantially as the priority shifted from climate stabilization to energy provision. Our results indicate a significant potential to integrate energy security targets into sustainable pathways to climate stabilization but underpin the trade-offs of divergent policy-driven agendas.

Environmental impact of the supervised toothbrushing programme amongst children in Scotland

ObjectivesTo understand the environmental impact of providing a nationwide supervised toothbrushing programme (Childsmile) for 5-year-old children in Scotland. MethodsA life cycle assessment was conducted to assess the annual environmental effects of the supervised toothbrushing programme in early years childcare, as well as each dental procedure (dental restoration under local anaesthesia (LA), single tooth extraction under LA, and multiple teeth extraction under general anaesthesia) spanning from 2001/02 to 2009/10. The expected savings in annual carbon dioxide equivalent (CO2e) emissions for all combined dental treatments in subsequent years were calculated compared to those in 2001/02. ResultsAn overall decrease in CO2e emissions was evident in the Childsmile programme and across all dental procedures. The estimated reduction in emissions across all procedures varied from 102.5 tonnes in 2002/03 to 461.1 tonnes in 2009/10 when compared to 2001/02. Within three years, the expected emissions savings from all combined dental procedures surpassed the emissions generated by implementing the Childsmile programme. ConclusionsOver time, there was a significant reduction in annual CO2e emissions for all combined dental treatments in children. In the eighth year of the Childsmile, emissions savings were more than 4.5 times greater than the emissions generated during its implementation. Clinical significanceThe study highlights the importance of educating public by individual dentists about the environmental impact of caries prevention programmes and paediatric dental treatments as this may influence patient choice. It also encourages commissioners of community dental programmes to support the implementation of supervised toothbrushing programmes in early years childcare.

Estimating the environmental impacts of global lithium-ion battery supply chain: A temporal, geographical, and technological perspective.

A sustainable low-carbon transition via electric vehicles will require a comprehensive understanding of lithium-ion batteries' global supply chain environmental impacts. Here, we analyze the cradle-to-gate energy use and greenhouse gas emissions of current and future nickel-manganese-cobalt and lithium-iron-phosphate battery technologies. We consider existing battery supply chains and future electricity grid decarbonization prospects for countries involved in material mining and battery production. Currently, around two-thirds of the total global emissions associated with battery production are highly concentrated in three countries as follows: China (45%), Indonesia (13%), and Australia (9%). On a unit basis, projected electricity grid decarbonization could reduce emissions of future battery production by up to 38% by 2050. An aggressive electric vehicle uptake scenario could result in cumulative emissions of 8.1 GtCO2eq by 2050 due to the manufacturing of nickel-based chemistries. However, a switch to lithium iron phosphate-based chemistry could enable emission savings of about 1.5 GtCO2eq. Secondary materials, via recycling, can help reduce primary supply requirements and alleviate the environmental burdens associated with the extraction and processing of materials from primary sources, where direct recycling offers the lowest impacts, followed by hydrometallurgical and pyrometallurgical, reducing greenhouse gas emissions by 61, 51, and 17%, respectively. This study can inform global and regional clean energy strategies to boost technology innovations, decarbonize the electricity grid, and optimize the global supply chain toward a net-zero future.

Quantifying emissions and enhancing inclusivity: Insights from ASCO attendance data.

442 Background: In-person conference attendance contributes significantly to a professional’s annual greenhouse gas (GHG) emissions. However, estimating conference emissions has often relied on assumptions about attendee numbers and travel, especially for investigations of medical conferences. This project aims to address these limitations by utilizing actual attendance data from the American Society of Clinical Oncology’s (ASCO) Annual Meetings. The objectives of this project are to establish a quantitative baseline of conference-associated emissions for different formats (in-person, virtual, and hybrid) and simulate changes to conference parameters with evaluation of associated emissions to provide recommendations for sustainable changes. Methods: Data was provided by ASCO including the number of attendees, zip codes of origin, and attendance method (in-person versus virtual) for their 2019-2022 Annual Meetings. Using a variety of conservative assumptions, emissions were calculated with consideration of the following factors: travel versus virtual attendance, conference space utilization, hotel stays, and electricity. The results were stratified by country, attendance method, and year, and differences in emissions were assessed with t-tests. Simulations were conducted to evaluate the impact of different conference sizes, locations, and formats on emissions. Results: The highest estimated GHG emissions were associated with the in-person 2019 conference, totaling 37,251 metric tons of carbon dioxide equivalents. While international attendees accounted for the largest proportion of emissions (>50%) in all years, optimizing conference locations models only reduced emissions by 3%. However, simulations of hub-and-spoke models showed the potential for larger decreases of up to 86%, and various hybrid models offered similar emission savings. Furthermore, hybrid conferences in 2020 and 2021 demonstrated increased attendee diversity with a higher percentage of international attendees compared to the in-person 2019 conference (44% international attendance in 2019 versus 53% in 2020 and 54% in 2021). Conclusions: This study not only quantifies the emissions impact of alternative conference formats but also highlights the importance of diversity, equity, and inclusion (DEI) considerations in reducing emissions. While travel remains a significant contributor to conference emissions, conference models focusing solely on location optimization were not as effective as hybrid models in reducing emissions. Hybrid models may present an opportunity to effectively mitigate GHG emissions while maintaining networking opportunities and cultivating inclusivity for attendees from diverse backgrounds.

Policy simulation modelling to inform national carbon budget pathways

Carbon budgets are emerging as a key policy tool to set cumulative targets on greenhouse gas emissions at a national and international level. In this paper, we develop a methodology for simulation modelling of energy demand and carbon dioxide (CO2eq.) emissions to assess the implication of different scenarios on sectoral emissions ceilings and carbon budgets. We demonstrate how this simulation modelling approach to carbon budgets applies to Ireland's Climate Action Bill, which sets a legal obligation to keep within defined sectoral emission ceilings. The transport, residential, industry, and electricity sectors meet Carbon Budget 1 (2021–2025), and the residential and services sector meets Carbon Budget 2 (2026–2030) sectoral ceilings in the scenario presented. This paper also examines the interaction effect between these policy scenarios. The interaction effect between public transport and modal shift shows an additional emissions savings of 0.1 MtCO2eq. The interaction effect also highlights a ‘double counting’ effect between the uptake of Electric Vehicles (EVs) and increased biofuel mixing for private car transport of 0.3 MtCO2eq., and for Evs and passenger transport modal shift of 0.2 MtCO2eq.

Waste heat upgrading with high-temperature heat pumps for assisting steam generation in ships: Performance, cost and emissions benefits

An alternative waste heat recovery technology is examined based on a high-temperature heat pump (HTHP) for heat upgrading in ships. This solution exploits the low-temperature heat of the cooling water of marine engines at 85 °C with two integration options, for either preheating the water before entering the auxiliary (steam) boiler or directly generating 6-bar steam for a vessel’s needs. An electric-driven heat pump cycle is used with an economizer for increasing the Coefficient of Performance (COP) and the heating capacity, while reducing the discharge temperature of the compressor. An ultra-low GWP refrigerant (R1233zd(E)) with a high enough critical temperature is considered. The sizing parameters of the HTHP are examined with the use of a validated numerical model attempting to find the best match between high performance and short discounted payback period (PBP). The latter is estimated with appropriate cost correlations that relate the component sizing with the equipment cost, in order to calculate the total capital cost. The operating costs on the other hand depend on the net fuel savings, i.e. fuel savings minus the fuel required to generate the electricity for the heat pump, the fixed operating cost such as for maintenance and service and the fuel price. The net emissions savings of the HTHP are also examined in a variety of ship types and sizes, based on their typical specific factors. The results show that the proposed solution leads to significant net fuel savings especially in oil tankers and cruise ships, reducing the boiler’s fuel consumption by up to 2.5%. But due to the low COP of the steam generation HTHP case of around 2, a very long PBP is achieved of over 20–30 years, whereas the preheat case always leads to a very short PBP of 2–6 years in all ship types, even though its capacity is low. Moreover, the net total emissions savings are significant especially for the preheat case, although additional fuel is consumed for producing electricity to drive the HTHP, while NOx and CO emissions are increased with the steam generation HTHP.

Environmental and Economic Sustainability Impacts of Metal Additive Manufacturing: A Study in the Industrial Machinery and Aeronautical Sectors

Metal additive manufacturing has emerged as a promising alternative to conventional manufacturing in various industries, offering advantages like complex geometries and reduced material waste. However, there is a research gap in the form of comparative and industry-specific investigations and case studies to comprehensively assess the environmental and economic impact of metal additive manufacturing.This study focuses on two significant sectors, industrial machinery and aeronautics, to understand how metal additive manufacturing influences environmental and economic sustainability compared to conventional manufacturing. Therefore, taking a life cycle approach, the environmental and economic impacts of this technology are evaluated and compared to conventional manufacturing through representative case studies in the two sectors using life cycle assessment and life cycle cost methodologies.The economic evaluation reveals that metal additive manufacturing reduces the total cost for aeronautical components by 33.2 %, even considering several post-processing operations. While for industrial machinery parts, this cost increases by 79.3 % due to high machine and material cost. However, this technology reduces the potential environmental impact by more than 60 % for both sectors, mainly due to reduced material consumption. The use phase for aeronautical components further contributes to environmental and economic benefits, with significant fuel and CO2 emissions savings. The results emphasize the sector-dependent nature of metal additive manufacturing's environmental and economic impact and underscore the importance of a life cycle perspective for informed decision-making.Some critical points for sustainable adoption of metal additive manufacturing in each sector are equipment investment, the post-processing applied, the material selected or, for the aeronautical industry, the impact of the use phase. Nevertheless, future developments are needed to address powder reuse, optimization, certification, and the social impact of metal additive manufacturing.

Dynamic simulation of a 4th generation district heating network with the presence of prosumers

District Heating Network is identified as a promising technology for decarbonizing urban areas. Thanks to the surplus of heat available from distributed renewable energy plants, a typical heat consumer of the network could become an energy producer during the day (typically referred to as a “prosumer”). Most of the models for thermal grids developed during past years usually assumed a centralized production of the consumed heat. The increasing presence of prosumers will require accurate dynamic modelling to monitor the changes induced in the thermohydraulic parameters of the network. To fill this knowledge gap, this paper aims at developing a model of a thermal grid with prosumers in the TRNSYS environment. The model allows for the dynamic monitoring of the main thermohydraulic parameters of the network. To show these capabilities, a ring-shaped network serving a cluster of 10 residential users located in Palermo (Italy) was assumed as the case study. Different scenarios are investigated based on the presence of solar collectors, prosumers along the network, and cooling by an absorption chiller. The achievable energy and emissions savings are calculated. The results of the study show that even only decreasing the operating temperature can significantly reduce heat losses via the network pipes. In particular, a temperature drop from 100 °C to 80 °C can reduce heat losses by 27.1%. Furthermore, the heat losses can be decreased by up to 52.8% when the network temperature is lowered from 100 °C to 60 °C. Additionally, the presence of prosumers and the solar field could lead to a 31.3% reduction in the energy produced by the centralized plant and a 17.6% reduction in energy consumed for pumping.