Residential Applications Research Articles

A systematic literature review of the bifacial photovoltaic module and its applications

AbstractBifacial modules can absorb radiation on both sides, increasing energy yield per unit area. Climatic conditions, mounting configuration, and system parameters influence the energy yield. The flexibility of bifacial modules allows for various installation orientations, including vertical and east‐west, which can help balance load profiles and reduce bottlenecks. Bifacial solar cells are found to provide higher current density and power compared to monofacial cells. Under optimum conditions, bifacial modules offer up to 30% more energy than conventional modules. Comparative assessments also demonstrate higher energy output from bifacial modules, especially on cloudy days, with low light intensity. Increasing ground reflectance (albedo) to 0.5 can further enhance the bifacial gain worldwide. The progress in performance modelling and accurate energy yield prediction has led to widespread adoption in residential and commercial applications and integration into emerging systems like floating PV and agro‐photovoltaic systems. Bifacial photovoltaic (PV) technology has received much interest, with the International Technology Roadmap for Photovoltaic (ITRPV) projecting a market share of 85% for bifacial PV cells by 2032. This study highlights the research on bifacial PV technology during the last 13 years and also discusses future trends and challenges. Furthermore, recommendations are made to ensure the bankability and scalability of bifacial PV modules.

Comprehensive Performance Analysis of Hybrid Solar Water Heating Systems: Synergizing Photovoltaic and Thermal Technologies

Abstract: Solar water heaters are an efficient and sustainable technology for meeting the growing demand for hot water in residential and commercial applications. This abstract presents a comprehensive overview of the performance evaluation of solar water heater systems through an extensive experimental study. The study aims to assess the effectiveness and efficiency of different solar water heater configurations under varying operating conditions. The experimental investigation involved the measurement and analysis of key performance parameters such as solar collector efficiency, heat transfer efficiency, thermal storage capacity, and overall system efficiency. A range of factors including solar radiation intensity, ambient temperature, water flow rate, and collector tilt angle were systematically varied to examine their impact on system performance. The results of the experimental study demonstrated the significant potential of solar water heaters in providing cost-effective and environmentally friendly hot water solutions. The solar collector efficiency was found to be highly influenced by the solar radiation intensity, with higher levels of solar irradiation leading to increased thermal energy generation. The heat transfer efficiency was optimized by adjusting the water flow rate and collector tilt angle, ensuring efficient transfer of heat from the collector to the water. Furthermore, the thermal storage capacity of the system played a crucial role in maintaining a consistent supply of hot water during periods of low solar radiation or high demand. Overall system efficiency was found to be strongly dependent on the integration of efficient heat exchangers and insulation materials. Based on the experimental findings, recommendations for system design and optimization were formulated, highlighting the importance of proper sizing, selection of suitable materials, and appropriate control strategies. The results also identified areas for future research, such as the integration of advanced heat transfer enhancement techniques and the utilization of hybrid solar water heater systems

Priority-based scheduling in residential energy management systems integrated with renewable sources using adaptive Salp swarm algorithm

With the remarkable growth and implementation of communication technology, sensors, and measurement equipment in the Smart Grid (SG) environment, demand side management (DSM) and demand response (DRs) can be easily implementable in residential energy systems integrated with renewable energy sources (RES). Looking at this perspective, this paper suggests an intelligent and dynamic load-priority-based scheduling optimal smart residential energy management system (REMS). The objectives to achieve through priority-based scheduling in the case of a residential energy management system are multi-focussed in terms of peak load reduction, consumer choice of consumption according to priority basis, and cost-effectiveness towards electricity price savings. The issues related to uncertainties with RES due to environmental dependency must be incorporated into the DSM. A single objective discrete formulation based on the Adaptive Salp Swarm Algorithm (ASSA) has been done on modelling and optimizing the crucial system parameters for scheduling, ideally the operation of residential appliances, along with the sources and prioritized-based loads available. System constraints, consumer priorities, energy source availability, uncertainties, and objectives are considered in the formulation to justify the approach that is feasible in real-time conditions. To enhance the search capabilities of SSA, the control parameters vary optimally in both the exploration and exploitation stages of searching. Comparative results with genetic algorithms (GA), particle swarm optimization (PSO), and conventional SSA are presented in different cases, such as (1) traditional homes without REMS, (ii) smart homes with REMS (iii) smart homes using REMS with RES.

Flow-induced noise and vibration in axial fan: a case study

AbstractReducing axial fan noise is crucial in residential, commercial, and industrial applications. This study explores how attaching different add-on designs to axial fans reduces aerodynamic noise. Eight design cases were examined, including extending the outlet and inlet ducts, using Chevron nozzles, placing internal spherical balls in staggered and straight patterns, applying a wavy inner wall treatment, and combining some of these nozzle designs. CFD and acoustic analyses were performed using Ansys Fluent 2022 R1. Noise reduction was measured at the nozzle outlet in each design case. All nozzle modifications reduced noise levels, with noise reductions ranging from 3 to 10% at the blade tip and 26–55% at the outlet. As an add-on to existing fan cases, the design cases investigated in this study can potentially improve the acoustic environment in various settings. The findings of this study can contribute to the development of quieter axial fans.

Energy usage of spruce with waste face masks and spent coffee grounds as fuel in a pellet boiler

It is necessary to reduce dependency on fossil fuels for heating and waste generation, while also utilizing the energy potential of waste materials. One possibility is to create fuel pellets where waste makes up a small proportion so that the properties of the wood are not significantly altered with. This article investigates the energy usage of pellets containing spent coffee grounds (5 % or 10 %) and waste face masks (5 % or 10 %), with spruce sawdust as the primary input material (80 % or 90 %). The elemental, thermogravimetric, calorific value, mechanical durability, emission and performance characteristics, and ash melting temperatures of the pellets were evaluated during the experiment. The results were compared with respect to pure spruce sawdust pellets and the specified limit values for wood pellets in commercial and residential applications as specified in ISO 17225 [18]. Both tested samples met the element content limit (N, S, Cl, As, Cd, Cr, Cu, Pb, Hg, Ni, and Zn) for the highest quality grade (A1). No significant amounts of harmful elements were detected. The samples also complied with the limits of moisture content, ash content, and net calorific value (also known as lower calorific value). All samples met the emission limits in their respective classes (3, 4, or 5) according to STN EN 303-5+A1 [35]. However, the samples failed to meet the limit values for mechanical durability and ash melting temperatures. Despite this, the manufactured pellet samples represent a suitable fuel product for combustion purposes as a more sustainable thermal energy fuel.

Evaluating the performance of spherical, hemispherical, and tubular solar stills with various configurations - A detailed review

Solving global water shortages has become an urgent challenge, hindering sustainable development. Therefore, comparing different solar still designs from application and economic perspectives is necessary. Solar distillation is considered a major innovation in the alternative energy sector for purifying brackish or brine water into clean water. Despite the extensive literature on improved solar stills, determining the most efficient designs for residential and industrial applications remains difficult. This review compares the productivity of spherical, hemispherical, and tubular solar still designs. The aim is to study the factors that influence the efficiency of each type and to analyze recent research and results obtained under different conditions. The results show that innovations in solar distillation design can take many forms to improve efficiency and productivity. For example, adding parabolic mirrors can increase productivity in spherical, hemispherical, and tubular stills by 35 to 70%. Likewise, innovative designs such as rotating spheres and changing bowl shapes significantly increased the productivity of spherical and hemispherical stills. Likewise, retrofitting a still with vacuum generation technology can significantly increase yields by 50 to 70%. In addition, using nanomaterials, especially nanophase change materials (NPCM), has increased the efficiency of the spherical and tubular stills by 116.5%, producing 7.62 kg/m2 per day. Therefore, the NPCM-equipped model was still the most efficient option among the three designs.

Hydrogen storage solutions for residential heating: A thermodynamic and economic analysis with scale-up potential

The study presents a thermodynamic and economic assessment of different hydrogen storage solutions for heating purposes, powered by PV panels, of a 10-apartment residential building in Milan, and it focuses on compressed hydrogen, liquid hydrogen, and metal hydride. The technical assessment involves using Python to code thermodynamic models to address technical and thermodynamic performances. The economic analysis evaluates the CAPEX, the ROI, and the cost per unit of stored hydrogen and energy. The study aims to provide an accurate assessment of the thermodynamic and economic indicators of three of the storage methods introduced in the literature review, pointing out the one with the best techno-economic performance for further development and research. The performed analysis shows that compressed hydrogen represents the best alternative but its cost is still too high for small residential applications. Applying the technology to a big system case would enable the solution making it economically feasible.

Enhancing residential energy access with optimized stand-alone hybrid solar-diesel-battery systems in Buea, Cameroon

This study examined the optimal size of an autonomous hybrid renewable energy system (HRES) for a residential application in Buea, located in the southwest region of Cameroon. Two hybrid systems, PV-Battery and PV-Battery-Diesel, have been evaluated in order to determine which was the better option. The goal of this research was to propose a dependable, low-cost power source as an alternative to the unreliable and highly unstable electricity grid in Buea. The decision criterion for the proposed HRES was the cost of energy (COE), while the system’s dependability constraint was the loss of power supply probability (LPSP). The crayfish optimization algorithm (COA) was used to optimize the component sizes of the proposed HRES, and the results were contrasted to those obtained from the whale optimization algorithm (WOA), sine cosine algorithm (SCA), and grasshopper optimization algorithm (GOA). The MATLAB software was used to model the components, criteria, and constraints of this single-objective optimization problem. The results obtained after simulation for LPSP of less than 1% showed that the COA algorithm outperformed the other three techniques, regardless of the configuration. Indeed, the COE obtained using the COA algorithm was 0.06%, 0.12%, and 1% lower than the COE provided by the WOA, SCA, and GOA algorithms, respectively, for the PV-Battery configuration. Likewise, for the PV-Battery-Diesel configuration, the COE obtained using the COA algorithm was 0.065%, 0.13%, and 0.39% lower than the COE provided by the WOA, SCA, and GOA algorithms, respectively. A comparative analysis of the outcomes obtained for the two configurations indicated that the PV-Battery-Diesel configuration exhibited a COE that was 4.32% lower in comparison to the PV-Battery configuration. Finally, the impact of the LPSP reduction on the COE was assessed in the PV-Battery-Diesel configuration. The decrease in LPSP resulted in an increase in COE owing to the nominal capacity of the diesel generator.

Recent Developments in Hydrogen Production, Storage, and Transportation: Challenges, Opportunities, and Perspectives

Hydrogen (H2) is considered a suitable substitute for conventional energy sources because it is abundant and environmentally friendly. However, the widespread adoption of H2 as an energy source poses several challenges in H2 production, storage, safety, and transportation. Recent efforts to address these challenges have focused on improving the efficiency and cost-effectiveness of H2 production methods, developing advanced storage technologies to ensure safe handling and transportation of H2, and implementing comprehensive safety protocols. Furthermore, efforts are being made to integrate H2 into the existing energy infrastructure and explore new opportunities for its application in various sectors such as transportation, industry, and residential applications. Overall, recent developments in H2 production, storage, safety, and transportation have opened new avenues for the widespread adoption of H2 as a clean and sustainable energy source. This review highlights potential solutions to overcome the challenges associated with H2 production, storage, safety, and transportation. Additionally, it discusses opportunities to achieve a carbon-neutral society and reduce the dependence on fossil fuels.

Experimental insights into thermoelectric freezer systems: Feasibility and efficiency

This study presents an experimental investigation into the operational performance of a thermoelectric (TE) freezer system. A freezer unit is composed of two-stage thermoelectric modules, an aluminum plate fin heat exchanger sink with fans positioned either on top or directing airflow through the center, and a cooling block incorporating circulating icy water for heat dissipation. Three distinct configurations, featuring varying numbers of freezer units and fan arrangements, underwent testing using a 300-liter freezer prototype under typical room conditions, specifically at 21 °C. The findings illustrate that the minimum temperature inside the freezer cabinet can achieve −16.0 °C across all configurations. Moreover, the cooling capacity can reach up to 74.7 W, with the thermoelectric coefficient of performance (COP) achieving a maximum of 0.45, while the system COP ranges from 0.23 to 0.28. The minimum TE power consumption and TE system power consumption are recorded at 138.8 W and 174.4 W, respectively, suggesting feasibility for practical residential freezer applications. This investigation sets the stage for the development of TE freezers integrated with ice thermal storage applications.

Design and Manufacturing of Air Conditioning Coil

This paper consists of the detail design process of a cooling coil which is used in Evaporator of VARC System for given cooling load. The process consists of designing a part using the calculation and various other parameters. The stability of long-term materials is becoming increasingly important as the demand for air conditioning systems in commercial and residential applications grows. Because of temperature variations and heat flow, materials in air conditioning systems can fail, reducing the cooling effect of the system. Low thermal transitions through the coil's material cause a significant amount of heat to be wasted in the evaporator coil, which lowers the system's overall efficiency. This paper outlines the methodology used to choose the right material for the evaporator coil in an air conditioning system using the CES Granta design software. Based on design and functional requirements, nickel-chromium alloys, pure titanium, copper, low alloy steel, cast iron, and pure titanium are the candidates that made the shortlist for evaporator coils. The best candidates are low alloy steel, titanium, and stainless steel.

Comprehensive evaluation of flat pack modular building systems: Design, structural performance, and operational efficiency

The demand for innovative and sustainable building solutions has led to a growing interest in modular construction methods. Modular building units have gained popularity in recent years for both residential housing and emergency and temporary shelters. However, embodied carbon and energy accumulation from the transportation, storage, and reuse of modular building units have become a rising concern regarding overall sustainability performance. Therefore, this research focuses on addressing this concern by assessing innovative alternative solutions for flat-pack modular building units, with an emphasis on sustainable, eco-friendly, and portable building solutions utilizing deployable modular technology. Initially, based on existing conventional modular building practices, conceptual designs of three types of flat-pack techniques were introduced. These designs were then compared and ranked according to structural, design, operational, and environmental performance criteria. The findings indicate that overall, detachable 2D panelised modules are the most favorable flat-pack technique for both residential and emergency applications due to their superior performance in these criteria. Deployable flat-pack solutions also showed notable advantages in certain aspects, but detachable solutions outperformed these in most cases to a significant scale. The key contribution of this research lies in its comprehensive evaluation of flat-pack modular designs, providing insights into optimizing traditional systems for enhanced sustainability. This research also highlights the advantages of flat-pack solutions over traditional techniques, demonstrating their potential to significantly reduce transportation-related carbon emissions and improve modular construction practices, thereby promoting rapid, cost-effective, and eco-friendly building methods.

Energy Consumption Management of Residential Appliances Based on Load Signatures Decomposition

Nowadays, energy consumption management techniques in the residential side have gained significant importance due to their considerable influence on the control of power flow in distribution networks and especially the possibility of managing a huge part of domestic electrical demand during peak-load hours. Since the customer’s data are recorded in an aggregated form, therefore, in order to apply control approaches, it is necessary to use load pattern evaluation techniques (load signature). These methods capable to decomposition effective features that help control approaches to implement with more accuracy. In this article, features of residential loads have been extracted by using the signature of the aggregated consumer’s demand. Then these features have been evaluated by methods such as logistic regression, k-nearest neighborhood, and decision tree. By assessing the results, it was determined that among the extracted features, the first two features (consumed power and injected harmonics) covered more than 89% of the variance of the entire set, and with the help of using the principal component analysis method, it was determined that by reducing the number of features to 2, a considerable amount of computation is reduced and only about 4% of the accuracy is reduced. Also, the convolutional neural network approach was used to estimate the type of load, and by identifying controllable loads and applying remote home energy management methods, it was found that by increasing participation up to 80%, more than 41% of peak-load consumption could be shifted to off-peak hours.

Environmental presence and toxicological outcomes of the herbicide pendimethalin in teleost fish.

Herbicides are often detected in aquatic ecosystems due to residential and agricultural applications and can harm aquatic organisms once deposited into water systems. Pendimethalin is part of the dinitroaniline chemical family and is applied to crops like corn, legumes, potatoes, and soybeans. The potential toxicity of pendimethalin to aquatic species is understudied compared to other widely studied herbicides, like atrazine and glyphosate. The objectives of this review were to (1) collate information on sub-lethal responses to pendimethalin exposure in fish, (2) evaluate how exposure studies relate to environmental concentrations, and (3) identify putative bioindicators for exposure studies. Overall, studies reporting pendimethalin in water systems worldwide indicate a range of 100-300 ng/L, but levels have been reported as high as ~15 µg/g in sediment. In teleost fish, studies demonstrate developmental toxicity, immunotoxicity, and behavioral disruptions. The strongest evidence for pendimethalin-induced toxicity involves oxidative stress, although studies often test toxicity at higher concentrations than environmentally relevant levels. Using the Comparative Toxicogenomics Database, pathway analysis reveals linkages to neurotoxicity and mechanisms of neurodegeneration like "Ubiquitin Dependent Protein Degradation", "Microtubule Cytoskeleton", "Protein Oxidation and Aggregation in Aging", and "Parkinson's Disease". Other prominent pathways included those related to mTOR signaling and reproduction. Thus, two potential mechanisms underlying pendimethalin-induced toxicity in fish include the neural and reproductive systems. This review synthesizes current data regarding environmental fate and ecotoxicology of pendimethalin in teleost fish and points to some putative physiological and molecular responses that may be beneficial for assessing toxicity of the herbicide in future investigations.

Smart System for Reducing Standby Energy Consumption in Residential Appliances

Residential consumption represents one of the most important percentages of total electricity consumption. A considerable number of household appliances consume energy even when they are not in operation, i.e., they are in the so-called standby state, thus producing additional costs, which become significant over time. In this context, one method to solve this problem is to develop a smart system capable of severing the power connection to devices in standby mode, thereby conserving energy and reducing the energy costs. The first step in the design of this system consists of the identification and accurate measurement of the standby state, which was carried out for three of the most common household appliances. Then, by using an ESP32 microcontroller, a system was designed to manage the operation of a relay module based on the current consumption of the connected equipment. Control over the system was achieved through a web application that works across all devices equipped with a web browser, offering functionalities to adjust current value time delays and to manually switch the system on or off. Finally, the deployment of this system across the three appliances studied led to a reduction in the energy consumption in standby mode of 26.68 kWh per month.

Feasibility-sustainability study of power generation using solar energy at an industrial site: a case study from Egypt

BackgroundFossil fuel utilization is the biggest contributor to the emissions of greenhouse gases which are the main reason for global warming. Solar energy photovoltaic (PV) technology is one of the most rapidly rising technologies and is a sturdy candidate to replace fossil fuels due to its versatility. Egypt receives high solar intensity which makes it a perfect place for utilizing this technology. However, for the past years, the focus in Egypt was on using solar energy for residential applications, henceforth a research gap was identified in studying the feasibility of using solar energy for industrial applications in Egypt. To ensure the sustainability of this application, this feasibility study addresses technical, economic, environmental, and social aspects.ResultsA case study is investigated for utilizing solar PV panels for energy generation in Egypt at an industrial site. A food factory was studied under three scenarios. Scenario 1 is the baseline case for the other scenarios with fixed tilted PV panels and no storage, Scenario 2 is the same as Scenario 1 with difference in is the model of the PV panels with no tracking or storage system. Scenario 3 has a vertical axis tracking system. Software was used to simulate the performance of the three scenarios for 25 years. Results have shown that Scenario 1 and Scenario 2 had close values of the annual energy production. However, Scenario 3 produces 2047 MWh annually which is considerably higher. Finally, a sensitivity analysis is carried out to test the effect of some economic parameters on the financial feasibility.ConclusionsAll the three scenarios are found to be feasible. Scenario 1 has the shortest discounted payback period with a net present value of 414,110.12 USD, a nominal levelized cost of energy of 0.022 USD/kWh, and avoided CO2 emissions of 14,898.993 tons. Although Scenario 3 has higher costs, it has higher energy production and better impact on the environment with 18,891.435 tons of avoided CO2 emissions. The paper concluded that a generalization could be done about using solar PV systems in Egypt for energy generation to be sustainable and feasible technically, economically, and environmentally.

Thermal Performance of Conventional-Metal and Novel-Plastic Drain Water Heat Recovery Device

Drain water heat recovery (DWHR) systems are effective for reducing energy consumption by capturing waste heat from drain water and using it to preheat the primary water supply in buildings. However, traditional DWHR devices, with copper helical tubes wrapped around a central pipe, can be expensive for residential use, deterring homeowners. This study introduces an innovative 3D-printed DWHR design using Nylon PA material. This design eliminates contact and conduction resistances of helical tubes, resulting in reduced thermal resistance, weight, manufacturing cost, and improved performance. Experimental testing compares the new plastic DWHR device with the conventional metal one under steady and transient conditions. In addition, detailed heat transfer models and thermal networks are given for both devices. The plastic device consistently outperforms the metal one, achieving higher effectiveness within the first few minutes of operation across various water flow rates. This advantage is particularly beneficial for short-term drain water usage like sinks and showers. Additionally, the novel DWHR device maintains a 16–20% higher steady-state effectiveness at high flow rates. This innovative approach promises cost-effective and efficient heat recovery, making DWHR technology more accessible for residential and commercial applications.

Downstream natural gas composition across U.S. and Canada: implications for indoor methane leaks and hazardous air pollutant exposures

Previous research has shown that natural gas (NG) leaks from residential appliances are common, affecting greenhouse gas emission inventories and indoor air quality. To study these implications, we collected and analyzed 587 unburned NG samples from 481 residences over 17 North American cities for hydrocarbons, hazardous air pollutants, and organosulfur odorants. Nearly all (97% of) gas samples contained benzene (between-city mean: 2335 ppbv [95% CI: 2104, 2607]) with substantial variability between cities. Vancouver, Los Angeles, Calgary, and Denver had at least 2x higher mean benzene concentrations than other cities sampled, with Vancouver exhibiting a nearly 50x greater mean benzene level than the lowest-concentration city (Boston). We estimate that current U.S. and Canadian emissions inventories are missing an additional 25 000 [95% CI: 19 000, 34 000] and 4000 [95% CI: 3700, 5200] lbs benzene yr−1 through downstream NG leakage, respectively. Concentrations of odorants added for leak detection varied substantially across cities, indicating a lack of standardization. Houston, for instance, had 5x higher mean tert-butyl mercaptan levels than Toronto. Using these odorant measurements, we found that methane emissions as high as 0.0080–0.28 g h−1 and indoor benzene enhancements 0.0096–0.11 ppbv could go undetected by persons with an average sense of smell, with large uncertainties driven by smelling sensitivity, gas composition, and household conditions. We also observed larger leaks (>10 ppm ambient methane) in ∼4% of surveyed homes, confirming that indoor leakage occurs at varying degrees despite the presence of odorants. Overall, our results illustrate the importance of downstream NG composition to understand potential emissions, exposures, and odor-mediated leak detection levels. Given methane’s global warming potency, benzene’s toxicity, and wide variation in smelling abilities, our findings highlight the deficiencies regarding the sole reliance on odorization to alert and protect all occupants from indoor leaks.

Reducing e-waste in Europe: Examining the impact of environmental and financial literacy on the premature replacement of appliances across owner-occupier and rental residential properties using the EVIDENT serious game

AimAs premature replacement of residential appliances drives rising e-waste levels in Europe, analysis of the factors impacting consumer decision-making when faced with opportunities to extend (repair) or reduce appliance lifespans (premature replacement) is needed. This manuscript seeks to explore the impact of environmental and financial literacy on consumer willingness to seek repair of home appliances (over replacement) across owner-occupier and rental properties. The impact of financial salience within the informational frames of these decisions is also explored. MethodAn online discrete choice experiment was conducted using the EVIDENT serious game, a life-simulation game in which players manage a virtual home and face energy decisions. Participants (n = 1056) completed a series of 3 choice experiments exploring repair/replace decision-making and willingness to pay for repair. Prior to the game, measures of environmental literacy, financial literacy, household type, and sociodemographic factors were obtained using a pre-game survey. For rental properties, a further stated preference experiment was conducted to determine the impact of financial incentives on willingness to invest in more efficient appliances for both landlords and tenants. ResultsWhile an overall willingness to seek repair for broken home appliances was found, most participants selected to prematurely replace their broken appliance with a more efficient alternative. Participants aged over 51 were significantly less likely to choose a repair (p < .001), while those in non-full-time employment more likely to select a repair (p < .001). Limited impact of environmental and financial literacy on repair/replace decision-making was found, though financial knowledge, environmental knowledge, and environmental skills were associated with willingness to pay for repair. Willingness towards repair in rental properties (landlords and tenants) was found with tenants willing to pay 34–71.3 % more than homeowners for repair and landlords willing to pay 93.3–108.8 % more depending on the appliance. Mixed impacts of financial incentives in rental properties to surmount impacts of split incentives were found. While 86.6 % of landlords were willing to accept a small fee from tenants towards a more efficient appliances, 65.2 % of tenants were unwilling to pay such a fee. ConclusionResults cast light on the specific impacts of individual financial and environmental literacy, demographic factors, and residence type on early replacement decisions, providing valuable direction for future policy actions.

Techno-Economic Model of District Heating Energy Hub: The Case of Latvia

Up to 60% of Latvia’s energy resources are used as fuel for district heating systems. Heating sector is an important emitter of greenhouse gases – especially carbon dioxide. Therefore, reduction of carbon emissions of district heating systems are crucial in Latvia’s decarbonization efforts. One of the solutions is integration of energy hub in the district heating network. There are many types of energy hubs, and the most suitable solution must be found in each case. A goal of this study is to find the best solution for Latvia’s district heating systems to achieve decarbonization and use of green (renewable) hydrogen. This coincides with European Union’s plans to increase the use of green hydrogen not only in industrial and residential application, but in heat production as well.To facilitate the plans of the European Union and Latvia’s decarbonization needs a mathematical model made in Microsoft Excel is used as a method to explore the techno-economic aspects of the energy hub and its integration in the district heating system. Several alternatives are considered, and green hydrogen is used in all of those. Results show the economically most feasible alternative. Calculations are made on an annual term basis, considering such factors as electricity and district heating price, required capacity of electrolysis apparatus for hydrogen production etc.From the model some results are apparent – the price of electricity has a sizable impact on the economic feasibility of the project, and the best use for green hydrogen economics-wise may differ throughout the year as the price of electricity, hydrogen, district heating and methane gas change.